Commit graph

17,104 commits

Author SHA1 Message Date
Kuniyuki Iwashima
c0c8d419da af_unix: Add dead flag to struct scm_fp_list.
commit 7172dc93d6 upstream.

Commit 1af2dface5 ("af_unix: Don't access successor in unix_del_edges()
during GC.") fixed use-after-free by avoid accessing edge->successor while
GC is in progress.

However, there could be a small race window where another process could
call unix_del_edges() while gc_in_progress is true and __skb_queue_purge()
is on the way.

So, we need another marker for struct scm_fp_list which indicates if the
skb is garbage-collected.

This patch adds dead flag in struct scm_fp_list and set it true before
calling __skb_queue_purge().

Fixes: 1af2dface5 ("af_unix: Don't access successor in unix_del_edges() during GC.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240508171150.50601-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:24 +02:00
Kuniyuki Iwashima
3600729b7f af_unix: Try not to hold unix_gc_lock during accept().
commit fd86344823 upstream.

Commit dcf70df204 ("af_unix: Fix up unix_edge.successor for embryo
socket.") added spin_lock(&unix_gc_lock) in accept() path, and it
caused regression in a stress test as reported by kernel test robot.

If the embryo socket is not part of the inflight graph, we need not
hold the lock.

To decide that in O(1) time and avoid the regression in the normal
use case,

  1. add a new stat unix_sk(sk)->scm_stat.nr_unix_fds

  2. count the number of inflight AF_UNIX sockets in the receive
     queue under unix_state_lock()

  3. move unix_update_edges() call under unix_state_lock()

  4. avoid locking if nr_unix_fds is 0 in unix_update_edges()

Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202404101427.92a08551-oliver.sang@intel.com
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240413021928.20946-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:23 +02:00
Kuniyuki Iwashima
7b1ffbd3b2 af_unix: Remove lock dance in unix_peek_fds().
commit 118f457da9 upstream.

In the previous GC implementation, the shape of the inflight socket
graph was not expected to change while GC was in progress.

MSG_PEEK was tricky because it could install inflight fd silently
and transform the graph.

Let's say we peeked a fd, which was a listening socket, and accept()ed
some embryo sockets from it.  The garbage collection algorithm would
have been confused because the set of sockets visited in scan_inflight()
would change within the same GC invocation.

That's why we placed spin_lock(&unix_gc_lock) and spin_unlock() in
unix_peek_fds() with a fat comment.

In the new GC implementation, we no longer garbage-collect the socket
if it exists in another queue, that is, if it has a bridge to another
SCC.  Also, accept() will require the lock if it has edges.

Thus, we need not do the complicated lock dance.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240401173125.92184-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:23 +02:00
Kuniyuki Iwashima
de7921631f af_unix: Replace garbage collection algorithm.
commit 4090fa373f upstream.

If we find a dead SCC during iteration, we call unix_collect_skb()
to splice all skb in the SCC to the global sk_buff_head, hitlist.

After iterating all SCC, we unlock unix_gc_lock and purge the queue.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-15-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:23 +02:00
Kuniyuki Iwashima
324005012f af_unix: Assign a unique index to SCC.
commit bfdb01283e upstream.

The definition of the lowlink in Tarjan's algorithm is the
smallest index of a vertex that is reachable with at most one
back-edge in SCC.  This is not useful for a cross-edge.

If we start traversing from A in the following graph, the final
lowlink of D is 3.  The cross-edge here is one between D and C.

  A -> B -> D   D = (4, 3)  (index, lowlink)
  ^    |    |   C = (3, 1)
  |    V    |   B = (2, 1)
  `--- C <--'   A = (1, 1)

This is because the lowlink of D is updated with the index of C.

In the following patch, we detect a dead SCC by checking two
conditions for each vertex.

  1) vertex has no edge directed to another SCC (no bridge)
  2) vertex's out_degree is the same as the refcount of its file

If 1) is false, there is a receiver of all fds of the SCC and
its ancestor SCC.

To evaluate 1), we need to assign a unique index to each SCC and
assign it to all vertices in the SCC.

This patch changes the lowlink update logic for cross-edge so
that in the example above, the lowlink of D is updated with the
lowlink of C.

  A -> B -> D   D = (4, 1)  (index, lowlink)
  ^    |    |   C = (3, 1)
  |    V    |   B = (2, 1)
  `--- C <--'   A = (1, 1)

Then, all vertices in the same SCC have the same lowlink, and we
can quickly find the bridge connecting to different SCC if exists.

However, it is no longer called lowlink, so we rename it to
scc_index.  (It's sometimes called lowpoint.)

Also, we add a global variable to hold the last index used in DFS
so that we do not reset the initial index in each DFS.

This patch can be squashed to the SCC detection patch but is
split deliberately for anyone wondering why lowlink is not used
as used in the original Tarjan's algorithm and many reference
implementations.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-13-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:23 +02:00
Kuniyuki Iwashima
e0e23fc499 af_unix: Save O(n) setup of Tarjan's algo.
commit ba31b4a4e1 upstream.

Before starting Tarjan's algorithm, we need to mark all vertices
as unvisited.  We can save this O(n) setup by reserving two special
indices (0, 1) and using two variables.

The first time we link a vertex to unix_unvisited_vertices, we set
unix_vertex_unvisited_index to index.

During DFS, we can see that the index of unvisited vertices is the
same as unix_vertex_unvisited_index.

When we finalise SCC later, we set unix_vertex_grouped_index to each
vertex's index.

Then, we can know (i) that the vertex is on the stack if the index
of a visited vertex is >= 2 and (ii) that it is not on the stack and
belongs to a different SCC if the index is unix_vertex_grouped_index.

After the whole algorithm, all indices of vertices are set as
unix_vertex_grouped_index.

Next time we start DFS, we know that all unvisited vertices have
unix_vertex_grouped_index, and we can use unix_vertex_unvisited_index
as the not-on-stack marker.

To use the same variable in __unix_walk_scc(), we can swap
unix_vertex_(grouped|unvisited)_index at the end of Tarjan's
algorithm.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-10-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:23 +02:00
Kuniyuki Iwashima
27a07364ce af_unix: Fix up unix_edge.successor for embryo socket.
commit dcf70df204 upstream.

To garbage collect inflight AF_UNIX sockets, we must define the
cyclic reference appropriately.  This is a bit tricky if the loop
consists of embryo sockets.

Suppose that the fd of AF_UNIX socket A is passed to D and the fd B
to C and that C and D are embryo sockets of A and B, respectively.
It may appear that there are two separate graphs, A (-> D) and
B (-> C), but this is not correct.

     A --. .-- B
          X
     C <-' `-> D

Now, D holds A's refcount, and C has B's refcount, so unix_release()
will never be called for A and B when we close() them.  However, no
one can call close() for D and C to free skbs holding refcounts of A
and B because C/D is in A/B's receive queue, which should have been
purged by unix_release() for A and B.

So, here's another type of cyclic reference.  When a fd of an AF_UNIX
socket is passed to an embryo socket, the reference is indirectly held
by its parent listening socket.

  .-> A                            .-> B
  |   `- sk_receive_queue          |   `- sk_receive_queue
  |      `- skb                    |      `- skb
  |         `- sk == C             |         `- sk == D
  |            `- sk_receive_queue |           `- sk_receive_queue
  |               `- skb +---------'               `- skb +-.
  |                                                         |
  `---------------------------------------------------------'

Technically, the graph must be denoted as A <-> B instead of A (-> D)
and B (-> C) to find such a cyclic reference without touching each
socket's receive queue.

  .-> A --. .-- B <-.
  |        X        |  ==  A <-> B
  `-- C <-' `-> D --'

We apply this fixup during GC by fetching the real successor by
unix_edge_successor().

When we call accept(), we clear unix_sock.listener under unix_gc_lock
not to confuse GC.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-9-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:23 +02:00
Kuniyuki Iwashima
36f924e4bf af_unix: Save listener for embryo socket.
commit aed6ecef55 upstream.

This is a prep patch for the following change, where we need to
fetch the listening socket from the successor embryo socket
during GC.

We add a new field to struct unix_sock to save a pointer to a
listening socket.

We set it when connect() creates a new socket, and clear it when
accept() is called.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-8-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:23 +02:00
Kuniyuki Iwashima
3ee9b24bd6 af_unix: Detect Strongly Connected Components.
commit 3484f06317 upstream.

In the new GC, we use a simple graph algorithm, Tarjan's Strongly
Connected Components (SCC) algorithm, to find cyclic references.

The algorithm visits every vertex exactly once using depth-first
search (DFS).

DFS starts by pushing an input vertex to a stack and assigning it
a unique number.  Two fields, index and lowlink, are initialised
with the number, but lowlink could be updated later during DFS.

If a vertex has an edge to an unvisited inflight vertex, we visit
it and do the same processing.  So, we will have vertices in the
stack in the order they appear and number them consecutively in
the same order.

If a vertex has a back-edge to a visited vertex in the stack,
we update the predecessor's lowlink with the successor's index.

After iterating edges from the vertex, we check if its index
equals its lowlink.

If the lowlink is different from the index, it shows there was a
back-edge.  Then, we go backtracking and propagate the lowlink to
its predecessor and resume the previous edge iteration from the
next edge.

If the lowlink is the same as the index, we pop vertices before
and including the vertex from the stack.  Then, the set of vertices
is SCC, possibly forming a cycle.  At the same time, we move the
vertices to unix_visited_vertices.

When we finish the algorithm, all vertices in each SCC will be
linked via unix_vertex.scc_entry.

Let's take an example.  We have a graph including five inflight
vertices (F is not inflight):

  A -> B -> C -> D -> E (-> F)
       ^         |
       `---------'

Suppose that we start DFS from C.  We will visit C, D, and B first
and initialise their index and lowlink.  Then, the stack looks like
this:

  > B = (3, 3)  (index, lowlink)
    D = (2, 2)
    C = (1, 1)

When checking B's edge to C, we update B's lowlink with C's index
and propagate it to D.

    B = (3, 1)  (index, lowlink)
  > D = (2, 1)
    C = (1, 1)

Next, we visit E, which has no edge to an inflight vertex.

  > E = (4, 4)  (index, lowlink)
    B = (3, 1)
    D = (2, 1)
    C = (1, 1)

When we leave from E, its index and lowlink are the same, so we
pop E from the stack as single-vertex SCC.  Next, we leave from
B and D but do nothing because their lowlink are different from
their index.

    B = (3, 1)  (index, lowlink)
    D = (2, 1)
  > C = (1, 1)

Then, we leave from C, whose index and lowlink are the same, so
we pop B, D and C as SCC.

Last, we do DFS for the rest of vertices, A, which is also a
single-vertex SCC.

Finally, each unix_vertex.scc_entry is linked as follows:

  A -.  B -> C -> D  E -.
  ^  |  ^         |  ^  |
  `--'  `---------'  `--'

We use SCC later to decide whether we can garbage-collect the
sockets.

Note that we still cannot detect SCC properly if an edge points
to an embryo socket.  The following two patches will sort it out.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-7-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:23 +02:00
Kuniyuki Iwashima
856aacbe2c af_unix: Iterate all vertices by DFS.
commit 6ba76fd284 upstream.

The new GC will use a depth first search graph algorithm to find
cyclic references.  The algorithm visits every vertex exactly once.

Here, we implement the DFS part without recursion so that no one
can abuse it.

unix_walk_scc() marks every vertex unvisited by initialising index
as UNIX_VERTEX_INDEX_UNVISITED and iterates inflight vertices in
unix_unvisited_vertices and call __unix_walk_scc() to start DFS from
an arbitrary vertex.

__unix_walk_scc() iterates all edges starting from the vertex and
explores the neighbour vertices with DFS using edge_stack.

After visiting all neighbours, __unix_walk_scc() moves the visited
vertex to unix_visited_vertices so that unix_walk_scc() will not
restart DFS from the visited vertex.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-6-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:23 +02:00
Kuniyuki Iwashima
d2d9f382e2 af_unix: Link struct unix_edge when queuing skb.
commit 42f298c06b upstream.

Just before queuing skb with inflight fds, we call scm_stat_add(),
which is a good place to set up the preallocated struct unix_vertex
and struct unix_edge in UNIXCB(skb).fp.

Then, we call unix_add_edges() and construct the directed graph
as follows:

  1. Set the inflight socket's unix_sock to unix_edge.predecessor.
  2. Set the receiver's unix_sock to unix_edge.successor.
  3. Set the preallocated vertex to inflight socket's unix_sock.vertex.
  4. Link inflight socket's unix_vertex.entry to unix_unvisited_vertices.
  5. Link unix_edge.vertex_entry to the inflight socket's unix_vertex.edges.

Let's say we pass the fd of AF_UNIX socket A to B and the fd of B
to C.  The graph looks like this:

  +-------------------------+
  | unix_unvisited_vertices | <-------------------------.
  +-------------------------+                           |
  +                                                     |
  |     +--------------+             +--------------+   |         +--------------+
  |     |  unix_sock A | <---. .---> |  unix_sock B | <-|-. .---> |  unix_sock C |
  |     +--------------+     | |     +--------------+   | | |     +--------------+
  | .-+ |    vertex    |     | | .-+ |    vertex    |   | | |     |    vertex    |
  | |   +--------------+     | | |   +--------------+   | | |     +--------------+
  | |                        | | |                      | | |
  | |   +--------------+     | | |   +--------------+   | | |
  | '-> |  unix_vertex |     | | '-> |  unix_vertex |   | | |
  |     +--------------+     | |     +--------------+   | | |
  `---> |    entry     | +---------> |    entry     | +-' | |
        |--------------|     | |     |--------------|     | |
        |    edges     | <-. | |     |    edges     | <-. | |
        +--------------+   | | |     +--------------+   | | |
                           | | |                        | | |
    .----------------------' | | .----------------------' | |
    |                        | | |                        | |
    |   +--------------+     | | |   +--------------+     | |
    |   |   unix_edge  |     | | |   |   unix_edge  |     | |
    |   +--------------+     | | |   +--------------+     | |
    `-> | vertex_entry |     | | `-> | vertex_entry |     | |
        |--------------|     | |     |--------------|     | |
        |  predecessor | +---' |     |  predecessor | +---' |
        |--------------|       |     |--------------|       |
        |   successor  | +-----'     |   successor  | +-----'
        +--------------+             +--------------+

Henceforth, we denote such a graph as A -> B (-> C).

Now, we can express all inflight fd graphs that do not contain
embryo sockets.  We will support the particular case later.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:22 +02:00
Kuniyuki Iwashima
4fc7df1c6d af_unix: Allocate struct unix_edge for each inflight AF_UNIX fd.
commit 29b64e3540 upstream.

As with the previous patch, we preallocate to skb's scm_fp_list an
array of struct unix_edge in the number of inflight AF_UNIX fds.

There we just preallocate memory and do not use immediately because
sendmsg() could fail after this point.  The actual use will be in
the next patch.

When we queue skb with inflight edges, we will set the inflight
socket's unix_sock as unix_edge->predecessor and the receiver's
unix_sock as successor, and then we will link the edge to the
inflight socket's unix_vertex.edges.

Note that we set NULL to cloned scm_fp_list.edges in scm_fp_dup()
so that MSG_PEEK does not change the shape of the directed graph.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:22 +02:00
Kuniyuki Iwashima
9e98ba0c73 af_unix: Allocate struct unix_vertex for each inflight AF_UNIX fd.
commit 1fbfdfaa59 upstream.

We will replace the garbage collection algorithm for AF_UNIX, where
we will consider each inflight AF_UNIX socket as a vertex and its file
descriptor as an edge in a directed graph.

This patch introduces a new struct unix_vertex representing a vertex
in the graph and adds its pointer to struct unix_sock.

When we send a fd using the SCM_RIGHTS message, we allocate struct
scm_fp_list to struct scm_cookie in scm_fp_copy().  Then, we bump
each refcount of the inflight fds' struct file and save them in
scm_fp_list.fp.

After that, unix_attach_fds() inexplicably clones scm_fp_list of
scm_cookie and sets it to skb.  (We will remove this part after
replacing GC.)

Here, we add a new function call in unix_attach_fds() to preallocate
struct unix_vertex per inflight AF_UNIX fd and link each vertex to
skb's scm_fp_list.vertices.

When sendmsg() succeeds later, if the socket of the inflight fd is
still not inflight yet, we will set the preallocated vertex to struct
unix_sock.vertex and link it to a global list unix_unvisited_vertices
under spin_lock(&unix_gc_lock).

If the socket is already inflight, we free the preallocated vertex.
This is to avoid taking the lock unnecessarily when sendmsg() could
fail later.

In the following patch, we will similarly allocate another struct
per edge, which will finally be linked to the inflight socket's
unix_vertex.edges.

And then, we will count the number of edges as unix_vertex.out_degree.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:22 +02:00
Kuniyuki Iwashima
8eb55b667a af_unix: Remove CONFIG_UNIX_SCM.
commit 99a7a5b994 upstream.

Originally, the code related to garbage collection was all in garbage.c.

Commit f4e65870e5 ("net: split out functions related to registering
inflight socket files") moved some functions to scm.c for io_uring and
added CONFIG_UNIX_SCM just in case AF_UNIX was built as module.

However, since commit 97154bcf4d ("af_unix: Kconfig: make CONFIG_UNIX
bool"), AF_UNIX is no longer built separately.  Also, io_uring does not
support SCM_RIGHTS now.

Let's move the functions back to garbage.c

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20240129190435.57228-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:22 +02:00
Kuniyuki Iwashima
c0d56c028d af_unix: Remove io_uring code for GC.
commit 11498715f2 upstream.

Since commit 705318a99a ("io_uring/af_unix: disable sending
io_uring over sockets"), io_uring's unix socket cannot be passed
via SCM_RIGHTS, so it does not contribute to cyclic reference and
no longer be candidate for garbage collection.

Also, commit 6e5e6d2749 ("io_uring: drop any code related to
SCM_RIGHTS") cleaned up SCM_RIGHTS code in io_uring.

Let's do it in AF_UNIX as well by reverting commit 0091bfc817
("io_uring/af_unix: defer registered files gc to io_uring release")
and commit 1036908045 ("net: reclaim skb->scm_io_uring bit").

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20240129190435.57228-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:22 +02:00
Kuniyuki Iwashima
acc97866c1 af_unix: Try to run GC async.
commit d9f21b3613 upstream.

If more than 16000 inflight AF_UNIX sockets exist and the garbage
collector is not running, unix_(dgram|stream)_sendmsg() call unix_gc().
Also, they wait for unix_gc() to complete.

In unix_gc(), all inflight AF_UNIX sockets are traversed at least once,
and more if they are the GC candidate.  Thus, sendmsg() significantly
slows down with too many inflight AF_UNIX sockets.

However, if a process sends data with no AF_UNIX FD, the sendmsg() call
does not need to wait for GC.  After this change, only the process that
meets the condition below will be blocked under such a situation.

  1) cmsg contains AF_UNIX socket
  2) more than 32 AF_UNIX sent by the same user are still inflight

Note that even a sendmsg() call that does not meet the condition but has
AF_UNIX FD will be blocked later in unix_scm_to_skb() by the spinlock,
but we allow that as a bonus for sane users.

The results below are the time spent in unix_dgram_sendmsg() sending 1
byte of data with no FD 4096 times on a host where 32K inflight AF_UNIX
sockets exist.

Without series: the sane sendmsg() needs to wait gc unreasonably.

  $ sudo /usr/share/bcc/tools/funclatency -p 11165 unix_dgram_sendmsg
  Tracing 1 functions for "unix_dgram_sendmsg"... Hit Ctrl-C to end.
  ^C
       nsecs               : count     distribution
  [...]
      524288 -> 1048575    : 0        |                                        |
     1048576 -> 2097151    : 3881     |****************************************|
     2097152 -> 4194303    : 214      |**                                      |
     4194304 -> 8388607    : 1        |                                        |

  avg = 1825567 nsecs, total: 7477526027 nsecs, count: 4096

With series: the sane sendmsg() can finish much faster.

  $ sudo /usr/share/bcc/tools/funclatency -p 8702  unix_dgram_sendmsg
  Tracing 1 functions for "unix_dgram_sendmsg"... Hit Ctrl-C to end.
  ^C
       nsecs               : count     distribution
  [...]
         128 -> 255        : 0        |                                        |
         256 -> 511        : 4092     |****************************************|
         512 -> 1023       : 2        |                                        |
        1024 -> 2047       : 0        |                                        |
        2048 -> 4095       : 0        |                                        |
        4096 -> 8191       : 1        |                                        |
        8192 -> 16383      : 1        |                                        |

  avg = 410 nsecs, total: 1680510 nsecs, count: 4096

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240123170856.41348-6-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:22 +02:00
Kuniyuki Iwashima
4be073d590 af_unix: Return struct unix_sock from unix_get_socket().
commit 5b17307bd0 upstream.

Currently, unix_get_socket() returns struct sock, but after calling
it, we always cast it to unix_sk().

Let's return struct unix_sock from unix_get_socket().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240123170856.41348-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-04 14:42:22 +02:00
Sabrina Dubroca
b58a295d10 espintcp: remove encap socket caching to avoid reference leak
[ Upstream commit 028363685b ]

The current scheme for caching the encap socket can lead to reference
leaks when we try to delete the netns.

The reference chain is: xfrm_state -> enacp_sk -> netns

Since the encap socket is a userspace socket, it holds a reference on
the netns. If we delete the espintcp state (through flush or
individual delete) before removing the netns, the reference on the
socket is dropped and the netns is correctly deleted. Otherwise, the
netns may not be reachable anymore (if all processes within the ns
have terminated), so we cannot delete the xfrm state to drop its
reference on the socket.

This patch results in a small (~2% in my tests) performance
regression.

A GC-type mechanism could be added for the socket cache, to clear
references if the state hasn't been used "recently", but it's a lot
more complex than just not caching the socket.

Fixes: e27cca96cd ("xfrm: add espintcp (RFC 8229)")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-04 14:42:17 +02:00
Cong Wang
a7d6e0ac0a net_sched: Flush gso_skb list too during ->change()
[ Upstream commit 2d3cbfd6d5 ]

Previously, when reducing a qdisc's limit via the ->change() operation, only
the main skb queue was trimmed, potentially leaving packets in the gso_skb
list. This could result in NULL pointer dereference when we only check
sch->limit against sch->q.qlen.

This patch introduces a new helper, qdisc_dequeue_internal(), which ensures
both the gso_skb list and the main queue are properly flushed when trimming
excess packets. All relevant qdiscs (codel, fq, fq_codel, fq_pie, hhf, pie)
are updated to use this helper in their ->change() routines.

Fixes: 76e3cc126b ("codel: Controlled Delay AQM")
Fixes: 4b549a2ef4 ("fq_codel: Fair Queue Codel AQM")
Fixes: afe4fd0624 ("pkt_sched: fq: Fair Queue packet scheduler")
Fixes: ec97ecf1eb ("net: sched: add Flow Queue PIE packet scheduler")
Fixes: 10239edf86 ("net-qdisc-hhf: Heavy-Hitter Filter (HHF) qdisc")
Fixes: d4b36210c2 ("net: pkt_sched: PIE AQM scheme")
Reported-by: Will <willsroot@protonmail.com>
Reported-by: Savy <savy@syst3mfailure.io>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-22 14:12:15 +02:00
Abhishek Chauhan
8dde02229b net: Rename mono_delivery_time to tstamp_type for scalabilty
[ Upstream commit 4d25ca2d68 ]

mono_delivery_time was added to check if skb->tstamp has delivery
time in mono clock base (i.e. EDT) otherwise skb->tstamp has
timestamp in ingress and delivery_time at egress.

Renaming the bitfield from mono_delivery_time to tstamp_type is for
extensibilty for other timestamps such as userspace timestamp
(i.e. SO_TXTIME) set via sock opts.

As we are renaming the mono_delivery_time to tstamp_type, it makes
sense to start assigning tstamp_type based on enum defined
in this commit.

Earlier we used bool arg flag to check if the tstamp is mono in
function skb_set_delivery_time, Now the signature of the functions
accepts tstamp_type to distinguish between mono and real time.

Also skb_set_delivery_type_by_clockid is a new function which accepts
clockid to determine the tstamp_type.

In future tstamp_type:1 can be extended to support userspace timestamp
by increasing the bitfield.

Signed-off-by: Abhishek Chauhan <quic_abchauha@quicinc.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240509211834.3235191-2-quic_abchauha@quicinc.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Stable-dep-of: 3908feb1bd ("Bluetooth: L2CAP: copy RX timestamp to new fragments")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-09 09:43:57 +02:00
Sebastian Andrzej Siewior
202bca49b7 xdp: Reset bpf_redirect_info before running a xdp's BPF prog.
Ricardo reported a KASAN discovered use after free in v6.6-stable.

The syzbot starts a BPF program via xdp_test_run_batch() which assigns
ri->tgt_value via dev_hash_map_redirect() and the return code isn't
XDP_REDIRECT it looks like nonsense. So the output in
bpf_warn_invalid_xdp_action() appears once.
Then the TUN driver runs another BPF program (on the same CPU) which
returns XDP_REDIRECT without setting ri->tgt_value first. It invokes
bpf_trace_printk() to print four characters and obtain the required
return value. This is enough to get xdp_do_redirect() invoked which
then accesses the pointer in tgt_value which might have been already
deallocated.

This problem does not affect upstream because since commit
	401cb7dae8 ("net: Reference bpf_redirect_info via task_struct on PREEMPT_RT.")

the per-CPU variable is referenced via task's task_struct and exists on
the stack during NAPI callback. Therefore it is cleared once before the
first invocation and remains valid within the RCU section of the NAPI
callback.

Instead of performing the huge backport of the commit (plus its fix ups)
here is an alternative version which only resets the variable in
question prior invoking the BPF program.

Acked-by: Toke Høiland-Jørgensen <toke@kernel.org>
Reported-by: Ricardo Cañuelo Navarro <rcn@igalia.com>
Closes: https://lore.kernel.org/all/20250226-20250204-kasan-slab-use-after-free-read-in-dev_map_enqueue__submit-v3-0-360efec441ba@igalia.com/
Fixes: 97f91a7cf0 ("bpf: add bpf_redirect_map helper routine")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25 10:45:57 +02:00
Ricardo Cañuelo Navarro
c6fefcb71d sctp: detect and prevent references to a freed transport in sendmsg
commit f1a69a940d upstream.

sctp_sendmsg() re-uses associations and transports when possible by
doing a lookup based on the socket endpoint and the message destination
address, and then sctp_sendmsg_to_asoc() sets the selected transport in
all the message chunks to be sent.

There's a possible race condition if another thread triggers the removal
of that selected transport, for instance, by explicitly unbinding an
address with setsockopt(SCTP_SOCKOPT_BINDX_REM), after the chunks have
been set up and before the message is sent. This can happen if the send
buffer is full, during the period when the sender thread temporarily
releases the socket lock in sctp_wait_for_sndbuf().

This causes the access to the transport data in
sctp_outq_select_transport(), when the association outqueue is flushed,
to result in a use-after-free read.

This change avoids this scenario by having sctp_transport_free() signal
the freeing of the transport, tagging it as "dead". In order to do this,
the patch restores the "dead" bit in struct sctp_transport, which was
removed in
commit 47faa1e4c5 ("sctp: remove the dead field of sctp_transport").

Then, in the scenario where the sender thread has released the socket
lock in sctp_wait_for_sndbuf(), the bit is checked again after
re-acquiring the socket lock to detect the deletion. This is done while
holding a reference to the transport to prevent it from being freed in
the process.

If the transport was deleted while the socket lock was relinquished,
sctp_sendmsg_to_asoc() will return -EAGAIN to let userspace retry the
send.

The bug was found by a private syzbot instance (see the error report [1]
and the C reproducer that triggers it [2]).

Link: https://people.igalia.com/rcn/kernel_logs/20250402__KASAN_slab-use-after-free_Read_in_sctp_outq_select_transport.txt [1]
Link: https://people.igalia.com/rcn/kernel_logs/20250402__KASAN_slab-use-after-free_Read_in_sctp_outq_select_transport__repro.c [2]
Cc: stable@vger.kernel.org
Fixes: df132eff46 ("sctp: clear the transport of some out_chunk_list chunks in sctp_assoc_rm_peer")
Suggested-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Ricardo Cañuelo Navarro <rcn@igalia.com>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20250404-kasan_slab-use-after-free_read_in_sctp_outq_select_transport__20250404-v1-1-5ce4a0b78ef2@igalia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25 10:45:32 +02:00
Arkadiusz Bokowy
59b683594f Bluetooth: hci_event: Fix connection regression between LE and non-LE adapters
[ Upstream commit f6685a96c8 ]

Due to a typo during defining HCI errors it is not possible to connect
LE-capable device with BR/EDR only adapter. The connection is terminated
by the LE adapter because the invalid LL params error code is treated
as unsupported remote feature.

Fixes: 79c0868ad6 ("Bluetooth: hci_event: Use HCI error defines instead of magic values")
Signed-off-by: Arkadiusz Bokowy <arkadiusz.bokowy@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-28 21:59:53 +01:00
Florian Westphal
a561c6a034 netfilter: nf_tables: allow clone callbacks to sleep
commit fa23e0d4b7 upstream.

Sven Auhagen reports transaction failures with following error:
  ./main.nft:13:1-26: Error: Could not process rule: Cannot allocate memory
  percpu: allocation failed, size=16 align=8 atomic=1, atomic alloc failed, no space left

This points to failing pcpu allocation with GFP_ATOMIC flag.
However, transactions happen from user context and are allowed to sleep.

One case where we can call into percpu allocator with GFP_ATOMIC is
nft_counter expression.

Normally this happens from control plane, so this could use GFP_KERNEL
instead.  But one use case, element insertion from packet path,
needs to use GFP_ATOMIC allocations (nft_dynset expression).

At this time, .clone callbacks always use GFP_ATOMIC for this reason.

Add gfp_t argument to the .clone function and pass GFP_KERNEL or
GFP_ATOMIC flag depending on context, this allows all clone memory
allocations to sleep for the normal (transaction) case.

Cc: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-22 12:50:50 -07:00
Pablo Neira Ayuso
7fa2e2960f netfilter: nf_tables: use timestamp to check for set element timeout
commit 7395dfacff upstream.

Add a timestamp field at the beginning of the transaction, store it
in the nftables per-netns area.

Update set backend .insert, .deactivate and sync gc path to use the
timestamp, this avoids that an element expires while control plane
transaction is still unfinished.

.lookup and .update, which are used from packet path, still use the
current time to check if the element has expired. And .get path and dump
also since this runs lockless under rcu read size lock. Then, there is
async gc which also needs to check the current time since it runs
asynchronously from a workqueue.

Fixes: c3e1b005ed ("netfilter: nf_tables: add set element timeout support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Jianqi Ren <jianqi.ren.cn@windriver.com>
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-22 12:50:50 -07:00
Luiz Augusto von Dentz
efc30877bd Bluetooth: L2CAP: Fix corrupted list in hci_chan_del
commit ab4eedb790 upstream.

This fixes the following trace by reworking the locking of l2cap_conn
so instead of only locking when changing the chan_l list this promotes
chan_lock to a general lock of l2cap_conn so whenever it is being held
it would prevents the likes of l2cap_conn_del to run:

list_del corruption, ffff888021297e00->prev is LIST_POISON2 (dead000000000122)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:61!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 5896 Comm: syz-executor213 Not tainted 6.14.0-rc1-next-20250204-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:__list_del_entry_valid_or_report+0x12c/0x190 lib/list_debug.c:59
Code: 8c 4c 89 fe 48 89 da e8 32 8c 37 fc 90 0f 0b 48 89 df e8 27 9f 14 fd 48 c7 c7 a0 c0 60 8c 4c 89 fe 48 89 da e8 15 8c 37 fc 90 <0f> 0b 4c 89 e7 e8 0a 9f 14 fd 42 80 3c 2b 00 74 08 4c 89 e7 e8 cb
RSP: 0018:ffffc90003f6f998 EFLAGS: 00010246
RAX: 000000000000004e RBX: dead000000000122 RCX: 01454d423f7fbf00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffffff819f077c R09: 1ffff920007eded0
R10: dffffc0000000000 R11: fffff520007eded1 R12: dead000000000122
R13: dffffc0000000000 R14: ffff8880352248d8 R15: ffff888021297e00
FS:  00007f7ace6686c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7aceeeb1d0 CR3: 000000003527c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __list_del_entry_valid include/linux/list.h:124 [inline]
 __list_del_entry include/linux/list.h:215 [inline]
 list_del_rcu include/linux/rculist.h:168 [inline]
 hci_chan_del+0x70/0x1b0 net/bluetooth/hci_conn.c:2858
 l2cap_conn_free net/bluetooth/l2cap_core.c:1816 [inline]
 kref_put include/linux/kref.h:65 [inline]
 l2cap_conn_put+0x70/0xe0 net/bluetooth/l2cap_core.c:1830
 l2cap_sock_shutdown+0xa8a/0x1020 net/bluetooth/l2cap_sock.c:1377
 l2cap_sock_release+0x79/0x1d0 net/bluetooth/l2cap_sock.c:1416
 __sock_release net/socket.c:642 [inline]
 sock_close+0xbc/0x240 net/socket.c:1393
 __fput+0x3e9/0x9f0 fs/file_table.c:448
 task_work_run+0x24f/0x310 kernel/task_work.c:227
 ptrace_notify+0x2d2/0x380 kernel/signal.c:2522
 ptrace_report_syscall include/linux/ptrace.h:415 [inline]
 ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline]
 syscall_exit_work+0xc7/0x1d0 kernel/entry/common.c:173
 syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline]
 syscall_exit_to_user_mode+0x24a/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7aceeaf449
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7ace668218 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: fffffffffffffffc RBX: 00007f7acef39328 RCX: 00007f7aceeaf449
RDX: 000000000000000e RSI: 0000000020000100 RDI: 0000000000000004
RBP: 00007f7acef39320 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000004 R14: 00007f7ace668670 R15: 000000000000000b
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_del_entry_valid_or_report+0x12c/0x190 lib/list_debug.c:59
Code: 8c 4c 89 fe 48 89 da e8 32 8c 37 fc 90 0f 0b 48 89 df e8 27 9f 14 fd 48 c7 c7 a0 c0 60 8c 4c 89 fe 48 89 da e8 15 8c 37 fc 90 <0f> 0b 4c 89 e7 e8 0a 9f 14 fd 42 80 3c 2b 00 74 08 4c 89 e7 e8 cb
RSP: 0018:ffffc90003f6f998 EFLAGS: 00010246
RAX: 000000000000004e RBX: dead000000000122 RCX: 01454d423f7fbf00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffffff819f077c R09: 1ffff920007eded0
R10: dffffc0000000000 R11: fffff520007eded1 R12: dead000000000122
R13: dffffc0000000000 R14: ffff8880352248d8 R15: ffff888021297e00
FS:  00007f7ace6686c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7acef05b08 CR3: 000000003527c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Reported-by: syzbot+10bd8fe6741eedd2be2e@syzkaller.appspotmail.com
Tested-by: syzbot+10bd8fe6741eedd2be2e@syzkaller.appspotmail.com
Fixes: b4f82f9ed4 ("Bluetooth: L2CAP: Fix slab-use-after-free Read in l2cap_send_cmd")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-22 12:50:50 -07:00
Luiz Augusto von Dentz
5e8ce74fb0 Revert "Bluetooth: hci_core: Fix sleeping function called from invalid context"
[ Upstream commit ab6ab707a4 ]

This reverts commit 4d94f05558 which has
problems (see [1]) and is no longer needed since 581dd2dc16
("Bluetooth: hci_event: Fix using rcu_read_(un)lock while iterating")
has reworked the code where the original bug has been found.

[1] Link: https://lore.kernel.org/linux-bluetooth/877c55ci1r.wl-tiwai@suse.de/T/#t
Fixes: 4d94f05558 ("Bluetooth: hci_core: Fix sleeping function called from invalid context")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-22 12:50:38 -07:00
Justin Iurman
665d91b0e4 include: net: add static inline dst_dev_overhead() to dst.h
[ Upstream commit 0600cf40e9 ]

Add static inline dst_dev_overhead() function to include/net/dst.h. This
helper function is used by ioam6_iptunnel, rpl_iptunnel and
seg6_iptunnel to get the dev's overhead based on a cache entry
(dst_entry). If the cache is empty, the default and generic value
skb->mac_len is returned. Otherwise, LL_RESERVED_SPACE() over dst's dev
is returned.

Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Cc: Alexander Lobakin <aleksander.lobakin@intel.com>
Cc: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Stable-dep-of: c64a0727f9 ("net: ipv6: fix dst ref loop on input in seg6 lwt")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-07 16:45:42 +01:00
Guillaume Nault
661c63cb34 ipv4: Convert ip_route_input() to dscp_t.
[ Upstream commit 7e863e5db6 ]

Pass a dscp_t variable to ip_route_input(), instead of a plain u8, to
prevent accidental setting of ECN bits in ->flowi4_tos.

Callers of ip_route_input() to consider are:

  * input_action_end_dx4_finish() and input_action_end_dt4() in
    net/ipv6/seg6_local.c. These functions set the tos parameter to 0,
    which is already a valid dscp_t value, so they don't need to be
    adjusted for the new prototype.

  * icmp_route_lookup(), which already has a dscp_t variable to pass as
    parameter. We just need to remove the inet_dscp_to_dsfield()
    conversion.

  * br_nf_pre_routing_finish(), ip_options_rcv_srr() and ip4ip6_err(),
    which get the DSCP directly from IPv4 headers. Define a helper to
    read the .tos field of struct iphdr as dscp_t, so that these
    function don't have to do the conversion manually.

While there, declare *iph as const in br_nf_pre_routing_finish(),
declare its local variables in reverse-christmas-tree order and move
the "err = ip_route_input()" assignment out of the conditional to avoid
checkpatch warning.

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/e9d40781d64d3d69f4c79ac8a008b8d67a033e8d.1727807926.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 27843ce6ba ("ipvlan: ensure network headers are in skb linear part")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-07 16:45:39 +01:00
Jiayuan Chen
05a571ee23 bpf: Fix wrong copied_seq calculation
[ Upstream commit 36b62df568 ]

'sk->copied_seq' was updated in the tcp_eat_skb() function when the action
of a BPF program was SK_REDIRECT. For other actions, like SK_PASS, the
update logic for 'sk->copied_seq' was moved to tcp_bpf_recvmsg_parser()
to ensure the accuracy of the 'fionread' feature.

It works for a single stream_verdict scenario, as it also modified
sk_data_ready->sk_psock_verdict_data_ready->tcp_read_skb
to remove updating 'sk->copied_seq'.

However, for programs where both stream_parser and stream_verdict are
active (strparser purpose), tcp_read_sock() was used instead of
tcp_read_skb() (sk_data_ready->strp_data_ready->tcp_read_sock).
tcp_read_sock() now still updates 'sk->copied_seq', leading to duplicate
updates.

In summary, for strparser + SK_PASS, copied_seq is redundantly calculated
in both tcp_read_sock() and tcp_bpf_recvmsg_parser().

The issue causes incorrect copied_seq calculations, which prevent
correct data reads from the recv() interface in user-land.

We do not want to add new proto_ops to implement a new version of
tcp_read_sock, as this would introduce code complexity [1].

We could have added noack and copied_seq to desc, and then called
ops->read_sock. However, unfortunately, other modules didn’t fully
initialize desc to zero. So, for now, we are directly calling
tcp_read_sock_noack() in tcp_bpf.c.

[1]: https://lore.kernel.org/bpf/20241218053408.437295-1-mrpre@163.com

Fixes: e5c6de5fa0 ("bpf, sockmap: Incorrectly handling copied_seq")
Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Jiayuan Chen <mrpre@163.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://patch.msgid.link/20250122100917.49845-3-mrpre@163.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-27 04:10:50 -08:00
Jiayuan Chen
a26f95b6e3 strparser: Add read_sock callback
[ Upstream commit 0532a79efd ]

Added a new read_sock handler, allowing users to customize read operations
instead of relying on the native socket's read_sock.

Signed-off-by: Jiayuan Chen <mrpre@163.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://patch.msgid.link/20250122100917.49845-2-mrpre@163.com
Stable-dep-of: 36b62df568 ("bpf: Fix wrong copied_seq calculation")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-27 04:10:50 -08:00
Sabrina Dubroca
f1d5e6a5e4 tcp: drop secpath at the same time as we currently drop dst
[ Upstream commit 9b6412e697 ]

Xiumei reported hitting the WARN in xfrm6_tunnel_net_exit while
running tests that boil down to:
 - create a pair of netns
 - run a basic TCP test over ipcomp6
 - delete the pair of netns

The xfrm_state found on spi_byaddr was not deleted at the time we
delete the netns, because we still have a reference on it. This
lingering reference comes from a secpath (which holds a ref on the
xfrm_state), which is still attached to an skb. This skb is not
leaked, it ends up on sk_receive_queue and then gets defer-free'd by
skb_attempt_defer_free.

The problem happens when we defer freeing an skb (push it on one CPU's
defer_list), and don't flush that list before the netns is deleted. In
that case, we still have a reference on the xfrm_state that we don't
expect at this point.

We already drop the skb's dst in the TCP receive path when it's no
longer needed, so let's also drop the secpath. At this point,
tcp_filter has already called into the LSM hooks that may require the
secpath, so it should not be needed anymore. However, in some of those
places, the MPTCP extension has just been attached to the skb, so we
cannot simply drop all extensions.

Fixes: 68822bdf76 ("net: generalize skb freeing deferral to per-cpu lists")
Reported-by: Xiumei Mu <xmu@redhat.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/5055ba8f8f72bdcb602faa299faca73c280b7735.1739743613.git.sd@queasysnail.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-27 04:10:49 -08:00
Eric Dumazet
81f369b670 net: add dev_net_rcu() helper
[ Upstream commit 482ad2a4ac ]

dev->nd_net can change, readers should either
use rcu_read_lock() or RTNL.

We currently use a generic helper, dev_net() with
no debugging support. We probably have many hidden bugs.

Add dev_net_rcu() helper for callers using rcu_read_lock()
protection.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250205155120.1676781-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 71b8471c93 ("ipv4: use RCU protection in ipv4_default_advmss()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21 13:57:20 +01:00
Jiri Pirko
4cfecb7fc7 net: treat possible_net_t net pointer as an RCU one and add read_pnet_rcu()
[ Upstream commit 2034d90ae4 ]

Make the net pointer stored in possible_net_t structure annotated as
an RCU pointer. Change the access helpers to treat it as such.
Introduce read_pnet_rcu() helper to allow caller to dereference
the net pointer under RCU read lock.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 71b8471c93 ("ipv4: use RCU protection in ipv4_default_advmss()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21 13:57:20 +01:00
Eric Dumazet
afd983f102 ipv4: add RCU protection to ip4_dst_hoplimit()
[ Upstream commit 469308552c ]

ip4_dst_hoplimit() must use RCU protection to make
sure the net structure it reads does not disappear.

Fixes: fa50d974d1 ("ipv4: Namespaceify ip_default_ttl sysctl knob")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250205155120.1676781-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21 13:57:20 +01:00
Eric Dumazet
c40cb5c03e vrf: use RCU protection in l3mdev_l3_out()
[ Upstream commit 6d0ce46a93 ]

l3mdev_l3_out() can be called without RCU being held:

raw_sendmsg()
 ip_push_pending_frames()
  ip_send_skb()
   ip_local_out()
    __ip_local_out()
     l3mdev_ip_out()

Add rcu_read_lock() / rcu_read_unlock() pair to avoid
a potential UAF.

Fixes: a8e3e1a9f0 ("net: l3mdev: Add hook to output path")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250207135841.1948589-7-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21 13:57:07 +01:00
Ido Schimmel
d2f275112c net: sched: Fix truncation of offloaded action statistics
[ Upstream commit 811b8f534f ]

In case of tc offload, when user space queries the kernel for tc action
statistics, tc will query the offloaded statistics from device drivers.
Among other statistics, drivers are expected to pass the number of
packets that hit the action since the last query as a 64-bit number.

Unfortunately, tc treats the number of packets as a 32-bit number,
leading to truncation and incorrect statistics when the number of
packets since the last query exceeds 0xffffffff:

$ tc -s filter show dev swp2 ingress
filter protocol all pref 1 flower chain 0
filter protocol all pref 1 flower chain 0 handle 0x1
  skip_sw
  in_hw in_hw_count 1
        action order 1: mirred (Egress Redirect to device swp1) stolen
        index 1 ref 1 bind 1 installed 58 sec used 0 sec
        Action statistics:
        Sent 1133877034176 bytes 536959475 pkt (dropped 0, overlimits 0 requeues 0)
[...]

According to the above, 2111-byte packets were redirected which is
impossible as only 64-byte packets were transmitted and the MTU was
1500.

Fix by treating packets as a 64-bit number:

$ tc -s filter show dev swp2 ingress
filter protocol all pref 1 flower chain 0
filter protocol all pref 1 flower chain 0 handle 0x1
  skip_sw
  in_hw in_hw_count 1
        action order 1: mirred (Egress Redirect to device swp1) stolen
        index 1 ref 1 bind 1 installed 61 sec used 0 sec
        Action statistics:
        Sent 1370624380864 bytes 21416005951 pkt (dropped 0, overlimits 0 requeues 0)
[...]

Which shows that only 64-byte packets were redirected (1370624380864 /
21416005951 = 64).

Fixes: 3804070235 ("net/sched: Enable netdev drivers to update statistics of offloaded actions")
Reported-by: Joe Botha <joe@atomic.ac>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250204123839.1151804-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-17 09:40:14 +01:00
Alexandre Cassen
c6e1b2cac2 xfrm: delete intermediate secpath entry in packet offload mode
[ Upstream commit 600258d555 ]

Packets handled by hardware have added secpath as a way to inform XFRM
core code that this path was already handled. That secpath is not needed
at all after policy is checked and it is removed later in the stack.

However, in the case of IP forwarding is enabled (/proc/sys/net/ipv4/ip_forward),
that secpath is not removed and packets which already were handled are reentered
to the driver TX path with xfrm_offload set.

The following kernel panic is observed in mlx5 in such case:

 mlx5_core 0000:04:00.0 enp4s0f0np0: Link up
 mlx5_core 0000:04:00.1 enp4s0f1np1: Link up
 Initializing XFRM netlink socket
 IPsec XFRM device driver
 BUG: kernel NULL pointer dereference, address: 0000000000000000
 #PF: supervisor instruction fetch in kernel mode
 #PF: error_code(0x0010) - not-present page
 PGD 0 P4D 0
 Oops: Oops: 0010 [#1] PREEMPT SMP
 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.13.0-rc1-alex #3
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
 RIP: 0010:0x0
 Code: Unable to access opcode bytes at 0xffffffffffffffd6.
 RSP: 0018:ffffb87380003800 EFLAGS: 00010206
 RAX: ffff8df004e02600 RBX: ffffb873800038d8 RCX: 00000000ffff98cf
 RDX: ffff8df00733e108 RSI: ffff8df00521fb80 RDI: ffff8df001661f00
 RBP: ffffb87380003850 R08: ffff8df013980000 R09: 0000000000000010
 R10: 0000000000000002 R11: 0000000000000002 R12: ffff8df001661f00
 R13: ffff8df00521fb80 R14: ffff8df00733e108 R15: ffff8df011faf04e
 FS:  0000000000000000(0000) GS:ffff8df46b800000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: ffffffffffffffd6 CR3: 0000000106384000 CR4: 0000000000350ef0
 Call Trace:
  <IRQ>
  ? show_regs+0x63/0x70
  ? __die_body+0x20/0x60
  ? __die+0x2b/0x40
  ? page_fault_oops+0x15c/0x550
  ? do_user_addr_fault+0x3ed/0x870
  ? exc_page_fault+0x7f/0x190
  ? asm_exc_page_fault+0x27/0x30
  mlx5e_ipsec_handle_tx_skb+0xe7/0x2f0 [mlx5_core]
  mlx5e_xmit+0x58e/0x1980 [mlx5_core]
  ? __fib_lookup+0x6a/0xb0
  dev_hard_start_xmit+0x82/0x1d0
  sch_direct_xmit+0xfe/0x390
  __dev_queue_xmit+0x6d8/0xee0
  ? __fib_lookup+0x6a/0xb0
  ? internal_add_timer+0x48/0x70
  ? mod_timer+0xe2/0x2b0
  neigh_resolve_output+0x115/0x1b0
  __neigh_update+0x26a/0xc50
  neigh_update+0x14/0x20
  arp_process+0x2cb/0x8e0
  ? __napi_build_skb+0x5e/0x70
  arp_rcv+0x11e/0x1c0
  ? dev_gro_receive+0x574/0x820
  __netif_receive_skb_list_core+0x1cf/0x1f0
  netif_receive_skb_list_internal+0x183/0x2a0
  napi_complete_done+0x76/0x1c0
  mlx5e_napi_poll+0x234/0x7a0 [mlx5_core]
  __napi_poll+0x2d/0x1f0
  net_rx_action+0x1a6/0x370
  ? atomic_notifier_call_chain+0x3b/0x50
  ? irq_int_handler+0x15/0x20 [mlx5_core]
  handle_softirqs+0xb9/0x2f0
  ? handle_irq_event+0x44/0x60
  irq_exit_rcu+0xdb/0x100
  common_interrupt+0x98/0xc0
  </IRQ>
  <TASK>
  asm_common_interrupt+0x27/0x40
 RIP: 0010:pv_native_safe_halt+0xb/0x10
 Code: 09 c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 0f 22
 0f 1f 84 00 00 00 00 00 90 eb 07 0f 00 2d 7f e9 36 00 fb
40 00 83 ff 07 77 21 89 ff ff 24 fd 88 3d a1 bd 0f 21 f8
 RSP: 0018:ffffffffbe603de8 EFLAGS: 00000202
 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000f92f46680
 RDX: 0000000000000037 RSI: 00000000ffffffff RDI: 00000000000518d4
 RBP: ffffffffbe603df0 R08: 000000cd42e4dffb R09: ffffffffbe603d70
 R10: 0000004d80d62680 R11: 0000000000000001 R12: ffffffffbe60bf40
 R13: 0000000000000000 R14: 0000000000000000 R15: ffffffffbe60aff8
  ? default_idle+0x9/0x20
  arch_cpu_idle+0x9/0x10
  default_idle_call+0x29/0xf0
  do_idle+0x1f2/0x240
  cpu_startup_entry+0x2c/0x30
  rest_init+0xe7/0x100
  start_kernel+0x76b/0xb90
  x86_64_start_reservations+0x18/0x30
  x86_64_start_kernel+0xc0/0x110
  ? setup_ghcb+0xe/0x130
  common_startup_64+0x13e/0x141
  </TASK>
 Modules linked in: esp4_offload esp4 xfrm_interface
xfrm6_tunnel tunnel4 tunnel6 xfrm_user xfrm_algo binfmt_misc
intel_rapl_msr intel_rapl_common kvm_amd ccp kvm input_leds serio_raw
qemu_fw_cfg sch_fq_codel dm_multipath scsi_dh_rdac scsi_dh_emc
scsi_dh_alua efi_pstore ip_tables x_tables autofs4 raid10 raid456
async_raid6_recov async_memcpy async_pq raid6_pq async_xor xor async_tx
libcrc32c raid1 raid0 mlx5_core crct10dif_pclmul crc32_pclmul
polyval_clmulni polyval_generic ghash_clmulni_intel sha256_ssse3
sha1_ssse3 ahci mlxfw i2c_i801 libahci i2c_mux i2c_smbus psample
virtio_rng pci_hyperv_intf aesni_intel crypto_simd cryptd
 CR2: 0000000000000000
 ---[ end trace 0000000000000000 ]---
 RIP: 0010:0x0
 Code: Unable to access opcode bytes at 0xffffffffffffffd6.
 RSP: 0018:ffffb87380003800 EFLAGS: 00010206
 RAX: ffff8df004e02600 RBX: ffffb873800038d8 RCX: 00000000ffff98cf
 RDX: ffff8df00733e108 RSI: ffff8df00521fb80 RDI: ffff8df001661f00
 RBP: ffffb87380003850 R08: ffff8df013980000 R09: 0000000000000010
 R10: 0000000000000002 R11: 0000000000000002 R12: ffff8df001661f00
 R13: ffff8df00521fb80 R14: ffff8df00733e108 R15: ffff8df011faf04e
 FS:  0000000000000000(0000) GS:ffff8df46b800000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: ffffffffffffffd6 CR3: 0000000106384000 CR4: 0000000000350ef0
 Kernel panic - not syncing: Fatal exception in interrupt
 Kernel Offset: 0x3b800000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
 ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

Fixes: 5958372ddf ("xfrm: add RX datapath protection for IPsec packet offload mode")
Signed-off-by: Alexandre Cassen <acassen@corp.free.fr>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08 09:52:28 +01:00
Pablo Neira Ayuso
d9aaae892d netfilter: nf_tables: fix set size with rbtree backend
[ Upstream commit 8d738c1869 ]

The existing rbtree implementation uses singleton elements to represent
ranges, however, userspace provides a set size according to the number
of ranges in the set.

Adjust provided userspace set size to the number of singleton elements
in the kernel by multiplying the range by two.

Check if the no-match all-zero element is already in the set, in such
case release one slot in the set size.

Fixes: 0ed6389c48 ("netfilter: nf_tables: rename set implementations")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08 09:52:03 +01:00
Florian Westphal
6f8277b97a netfilter: nf_tables: de-constify set commit ops function argument
[ Upstream commit 2560016721 ]

The set backend using this already has to work around this via ugly
cast, don't spread this pattern.

Signed-off-by: Florian Westphal <fw@strlen.de>
Stable-dep-of: 8d738c1869 ("netfilter: nf_tables: fix set size with rbtree backend")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08 09:52:03 +01:00
Eric Dumazet
7705d8a7f2 ax25: rcu protect dev->ax25_ptr
[ Upstream commit 95fc45d1de ]

syzbot found a lockdep issue [1].

We should remove ax25 RTNL dependency in ax25_setsockopt()

This should also fix a variety of possible UAF in ax25.

[1]

WARNING: possible circular locking dependency detected
6.13.0-rc3-syzkaller-00762-g9268abe611b0 #0 Not tainted
------------------------------------------------------
syz.5.1818/12806 is trying to acquire lock:
 ffffffff8fcb3988 (rtnl_mutex){+.+.}-{4:4}, at: ax25_setsockopt+0xa55/0xe90 net/ax25/af_ax25.c:680

but task is already holding lock:
 ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1618 [inline]
 ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: ax25_setsockopt+0x209/0xe90 net/ax25/af_ax25.c:574

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (sk_lock-AF_AX25){+.+.}-{0:0}:
        lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
        lock_sock_nested+0x48/0x100 net/core/sock.c:3642
        lock_sock include/net/sock.h:1618 [inline]
        ax25_kill_by_device net/ax25/af_ax25.c:101 [inline]
        ax25_device_event+0x24d/0x580 net/ax25/af_ax25.c:146
        notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85
       __dev_notify_flags+0x207/0x400
        dev_change_flags+0xf0/0x1a0 net/core/dev.c:9026
        dev_ifsioc+0x7c8/0xe70 net/core/dev_ioctl.c:563
        dev_ioctl+0x719/0x1340 net/core/dev_ioctl.c:820
        sock_do_ioctl+0x240/0x460 net/socket.c:1234
        sock_ioctl+0x626/0x8e0 net/socket.c:1339
        vfs_ioctl fs/ioctl.c:51 [inline]
        __do_sys_ioctl fs/ioctl.c:906 [inline]
        __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
        do_syscall_x64 arch/x86/entry/common.c:52 [inline]
        do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (rtnl_mutex){+.+.}-{4:4}:
        check_prev_add kernel/locking/lockdep.c:3161 [inline]
        check_prevs_add kernel/locking/lockdep.c:3280 [inline]
        validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
        __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
        lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
        __mutex_lock_common kernel/locking/mutex.c:585 [inline]
        __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735
        ax25_setsockopt+0xa55/0xe90 net/ax25/af_ax25.c:680
        do_sock_setsockopt+0x3af/0x720 net/socket.c:2324
        __sys_setsockopt net/socket.c:2349 [inline]
        __do_sys_setsockopt net/socket.c:2355 [inline]
        __se_sys_setsockopt net/socket.c:2352 [inline]
        __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2352
        do_syscall_x64 arch/x86/entry/common.c:52 [inline]
        do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sk_lock-AF_AX25);
                               lock(rtnl_mutex);
                               lock(sk_lock-AF_AX25);
  lock(rtnl_mutex);

 *** DEADLOCK ***

1 lock held by syz.5.1818/12806:
  #0: ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1618 [inline]
  #0: ffff8880617ac258 (sk_lock-AF_AX25){+.+.}-{0:0}, at: ax25_setsockopt+0x209/0xe90 net/ax25/af_ax25.c:574

stack backtrace:
CPU: 1 UID: 0 PID: 12806 Comm: syz.5.1818 Not tainted 6.13.0-rc3-syzkaller-00762-g9268abe611b0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
  __dump_stack lib/dump_stack.c:94 [inline]
  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
  print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
  check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
  check_prev_add kernel/locking/lockdep.c:3161 [inline]
  check_prevs_add kernel/locking/lockdep.c:3280 [inline]
  validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
  __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
  lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
  __mutex_lock_common kernel/locking/mutex.c:585 [inline]
  __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735
  ax25_setsockopt+0xa55/0xe90 net/ax25/af_ax25.c:680
  do_sock_setsockopt+0x3af/0x720 net/socket.c:2324
  __sys_setsockopt net/socket.c:2349 [inline]
  __do_sys_setsockopt net/socket.c:2355 [inline]
  __se_sys_setsockopt net/socket.c:2352 [inline]
  __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2352
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7b62385d29

Fixes: c433570458 ("ax25: fix a use-after-free in ax25_fillin_cb()")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250103210514.87290-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08 09:51:55 +01:00
Eric Dumazet
cb8449c349 inetpeer: remove create argument of inet_getpeer()
[ Upstream commit 7a596a50c4 ]

All callers of inet_getpeer() want to create an inetpeer.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241215175629.1248773-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: a853c60950 ("inetpeer: do not get a refcount in inet_getpeer()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08 09:51:53 +01:00
Eric Dumazet
fdaa6b3c7e inetpeer: remove create argument of inet_getpeer_v[46]()
[ Upstream commit 661cd8fc8e ]

All callers of inet_getpeer_v4() and inet_getpeer_v6()
want to create an inetpeer.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241215175629.1248773-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: a853c60950 ("inetpeer: do not get a refcount in inet_getpeer()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08 09:51:53 +01:00
Eric Dumazet
1e222169f7 net: add exit_batch_rtnl() method
[ Upstream commit fd4f101edb ]

Many (struct pernet_operations)->exit_batch() methods have
to acquire rtnl.

In presence of rtnl mutex pressure, this makes cleanup_net()
very slow.

This patch adds a new exit_batch_rtnl() method to reduce
number of rtnl acquisitions from cleanup_net().

exit_batch_rtnl() handlers are called while rtnl is locked,
and devices to be killed can be queued in a list provided
as their second argument.

A single unregister_netdevice_many() is called right
before rtnl is released.

exit_batch_rtnl() handlers are called before ->exit() and
->exit_batch() handlers.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Antoine Tenart <atenart@kernel.org>
Link: https://lore.kernel.org/r/20240206144313.2050392-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 46841c7053 ("gtp: Use for_each_netdev_rcu() in gtp_genl_dump_pdp().")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-23 17:21:10 +01:00
Zhongqiu Duan
91f89fe177 tcp/dccp: allow a connection when sk_max_ack_backlog is zero
[ Upstream commit 3479c7549f ]

If the backlog of listen() is set to zero, sk_acceptq_is_full() allows
one connection to be made, but inet_csk_reqsk_queue_is_full() does not.
When the net.ipv4.tcp_syncookies is zero, inet_csk_reqsk_queue_is_full()
will cause an immediate drop before the sk_acceptq_is_full() check in
tcp_conn_request(), resulting in no connection can be made.

This patch tries to keep consistent with 64a146513f ("[NET]: Revert
incorrect accept queue backlog changes.").

Link: https://lore.kernel.org/netdev/20250102080258.53858-1-kuniyu@amazon.com/
Fixes: ef547f2ac1 ("tcp: remove max_qlen_log")
Signed-off-by: Zhongqiu Duan <dzq.aishenghu0@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250102171426.915276-1-dzq.aishenghu0@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-17 13:36:12 +01:00
Jason Xing
b2c9204e21 tcp/dccp: complete lockless accesses to sk->sk_max_ack_backlog
[ Upstream commit 9a79c65f00 ]

Since commit 099ecf59f0 ("net: annotate lockless accesses to
sk->sk_max_ack_backlog") decided to handle the sk_max_ack_backlog
locklessly, there is one more function mostly called in TCP/DCCP
cases. So this patch completes it:)

Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240331090521.71965-1-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 3479c7549f ("tcp/dccp: allow a connection when sk_max_ack_backlog is zero")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-17 13:36:12 +01:00
Luiz Augusto von Dentz
bef3334183 Bluetooth: hci_core: Fix sleeping function called from invalid context
[ Upstream commit 4d94f05558 ]

This reworks hci_cb_list to not use mutex hci_cb_list_lock to avoid bugs
like the bellow:

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5070, name: kworker/u9:2
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
4 locks held by kworker/u9:2/5070:
 #0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
 #0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335
 #1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
 #1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335
 #2: ffff8880665d0078 (&hdev->lock){+.+.}-{3:3}, at: hci_le_create_big_complete_evt+0xcf/0xae0 net/bluetooth/hci_event.c:6914
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hci_le_create_big_complete_evt+0xdb/0xae0 net/bluetooth/hci_event.c:6915
CPU: 0 PID: 5070 Comm: kworker/u9:2 Not tainted 6.8.0-syzkaller-08073-g480e035fc4c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: hci0 hci_rx_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 __might_resched+0x5d4/0x780 kernel/sched/core.c:10187
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0xc1/0xd70 kernel/locking/mutex.c:752
 hci_connect_cfm include/net/bluetooth/hci_core.h:2004 [inline]
 hci_le_create_big_complete_evt+0x3d9/0xae0 net/bluetooth/hci_event.c:6939
 hci_event_func net/bluetooth/hci_event.c:7514 [inline]
 hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7569
 hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4171
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>

Reported-by: syzbot+2fb0835e0c9cefc34614@syzkaller.appspotmail.com
Tested-by: syzbot+2fb0835e0c9cefc34614@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=2fb0835e0c9cefc34614
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-09 13:32:05 +01:00
Pablo Neira Ayuso
4f49349c19 netfilter: nft_set_hash: unaligned atomic read on struct nft_set_ext
[ Upstream commit 542ed8145e ]

Access to genmask field in struct nft_set_ext results in unaligned
atomic read:

[   72.130109] Unable to handle kernel paging request at virtual address ffff0000c2bb708c
[   72.131036] Mem abort info:
[   72.131213]   ESR = 0x0000000096000021
[   72.131446]   EC = 0x25: DABT (current EL), IL = 32 bits
[   72.132209]   SET = 0, FnV = 0
[   72.133216]   EA = 0, S1PTW = 0
[   72.134080]   FSC = 0x21: alignment fault
[   72.135593] Data abort info:
[   72.137194]   ISV = 0, ISS = 0x00000021, ISS2 = 0x00000000
[   72.142351]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[   72.145989]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[   72.150115] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000237d27000
[   72.154893] [ffff0000c2bb708c] pgd=0000000000000000, p4d=180000023ffff403, pud=180000023f84b403, pmd=180000023f835403,
+pte=0068000102bb7707
[   72.163021] Internal error: Oops: 0000000096000021 [#1] SMP
[...]
[   72.170041] CPU: 7 UID: 0 PID: 54 Comm: kworker/7:0 Tainted: G            E      6.13.0-rc3+ #2
[   72.170509] Tainted: [E]=UNSIGNED_MODULE
[   72.170720] Hardware name: QEMU QEMU Virtual Machine, BIOS edk2-stable202302-for-qemu 03/01/2023
[   72.171192] Workqueue: events_power_efficient nft_rhash_gc [nf_tables]
[   72.171552] pstate: 21400005 (nzCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
[   72.171915] pc : nft_rhash_gc+0x200/0x2d8 [nf_tables]
[   72.172166] lr : nft_rhash_gc+0x128/0x2d8 [nf_tables]
[   72.172546] sp : ffff800081f2bce0
[   72.172724] x29: ffff800081f2bd40 x28: ffff0000c2bb708c x27: 0000000000000038
[   72.173078] x26: ffff0000c6780ef0 x25: ffff0000c643df00 x24: ffff0000c6778f78
[   72.173431] x23: 000000000000001a x22: ffff0000c4b1f000 x21: ffff0000c6780f78
[   72.173782] x20: ffff0000c2bb70dc x19: ffff0000c2bb7080 x18: 0000000000000000
[   72.174135] x17: ffff0000c0a4e1c0 x16: 0000000000003000 x15: 0000ac26d173b978
[   72.174485] x14: ffffffffffffffff x13: 0000000000000030 x12: ffff0000c6780ef0
[   72.174841] x11: 0000000000000000 x10: ffff800081f2bcf8 x9 : ffff0000c3000000
[   72.175193] x8 : 00000000000004be x7 : 0000000000000000 x6 : 0000000000000000
[   72.175544] x5 : 0000000000000040 x4 : ffff0000c3000010 x3 : 0000000000000000
[   72.175871] x2 : 0000000000003a98 x1 : ffff0000c2bb708c x0 : 0000000000000004
[   72.176207] Call trace:
[   72.176316]  nft_rhash_gc+0x200/0x2d8 [nf_tables] (P)
[   72.176653]  process_one_work+0x178/0x3d0
[   72.176831]  worker_thread+0x200/0x3f0
[   72.176995]  kthread+0xe8/0xf8
[   72.177130]  ret_from_fork+0x10/0x20
[   72.177289] Code: 54fff984 d503201f d2800080 91003261 (f820303f)
[   72.177557] ---[ end trace 0000000000000000 ]---

Align struct nft_set_ext to word size to address this and
documentation it.

pahole reports that this increases the size of elements for rhash and
pipapo in 8 bytes on x86_64.

Fixes: 7ffc748115 ("netfilter: nft_set_hash: skip duplicated elements pending gc run")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-09 13:32:01 +01:00
Rory Little
dc60941085 wifi: mac80211: Add non-atomic station iterator
[ Upstream commit 7c3b69eade ]

Drivers may at times want to iterate their stations with a function
which requires some non-atomic operations.

ieee80211_iterate_stations_mtx() introduces an API to iterate stations
while holding that wiphy's mutex. This allows the iterating function to
do non-atomic operations safely.

Signed-off-by: Rory Little <rory@candelatech.com>
Link: https://patch.msgid.link/20240806004024.2014080-2-rory@candelatech.com
[unify internal list iteration functions]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Stable-dep-of: 8fac3266c6 ("wifi: ath12k: fix atomic calls in ath12k_mac_op_set_bitrate_mask()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-09 13:31:42 +01:00
Ping-Ke Shih
24b5898a8c wifi: mac80211: export ieee80211_purge_tx_queue() for drivers
[ Upstream commit 53bc1b73b6 ]

Drivers need to purge TX SKB when stopping. Using skb_queue_purge() can't
report TX status to mac80211, causing ieee80211_free_ack_frame() warns
"Have pending ack frames!". Export ieee80211_purge_tx_queue() for drivers
to not have to reimplement it.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20240822014255.10211-1-pkshih@realtek.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Stable-dep-of: 3e5e4a801a ("wifi: rtw88: use ieee80211_purge_tx_queue() to purge TX skb")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-09 13:31:41 +01:00