Three inline predicates -- is_file_epoll(), ep_is_linked(),
ep_events_available() -- were declared to return int even though
their only use is as a truthy test and their bodies are already
boolean expressions. ep_has_wakeup_source(), in the same file,
returns bool, so the convention was already inconsistent.
Convert all three to return bool. Rewrite ep_events_available()'s
verbose kerneldoc to the same one-line style the rest of the
predicates use now.
ep_poll()'s local eavail variable stores the result of
ep_events_available() (already boolean), ep_busy_loop() (returns
bool), and list_empty() (int but tested as boolean). Split it out
of the combined int declaration and give it bool type; replace the
one "eavail = 1" after a wakeup with "eavail = true" to match.
No functional change.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Link: https://patch.msgid.link/20260424-work-epoll-rework-v1-16-249ed00a20f3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Two list-related names were confusing in isolation:
struct epitem::next
A singly-linked link slot used only when an epi is queued on
ep->ovflist during an ep_start_scan/ep_done_scan window. The
bare name "next" suggests a generic list link and doesn't say
which list it belongs to.
txlist
The caller-local list_head used by ep_send_events() and
__ep_eventpoll_poll() to hold the batch of items stolen from
ep->rdllist for the current scan. "txlist" ("transmission
list") is abbreviated and overloaded: it doesn't distinguish
itself from ep->rdllist or ep->ovflist at a glance.
Rename for what each actually is:
struct epitem::next -> struct epitem::ovflist_next
local txlist -> scan_batch
With these in place:
- epi->ovflist_next reads as "this is the ep->ovflist link slot",
matching the rdllink pattern above it.
- scan_batch reads as "the batch currently being scanned", clearly
distinct from rdllist (canonical ready list) and ovflist
(scan-window overflow).
ep->rdllist and ep->ovflist struct field names are preserved -- they
are long-standing interface-facing identifiers, and the new inline
helpers (ep_is_scanning, epi_on_ovflist, ...) already hide the
sentinel semantics at call sites.
No functional change.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Link: https://patch.msgid.link/20260424-work-epoll-rework-v1-15-249ed00a20f3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
ep->ovflist and epi->next both use EP_UNACTIVE_PTR (a cast to
(void *)-1) as a sentinel, with distinct meanings at each site:
ep->ovflist == EP_UNACTIVE_PTR no scan in progress
epi->next == EP_UNACTIVE_PTR epi not on ovflist
Call sites had to know the sentinel's value and, by convention, what
it meant in each context. Hide both behind inline helpers:
ep_is_scanning(ep) predicate for "scan in progress"
ep_enter_scan(ep) WRITE_ONCE flip to NULL (scan start)
ep_exit_scan(ep) WRITE_ONCE flip to sentinel (scan end)
epi_on_ovflist(epi) predicate for "epi is on ovflist"
epi_clear_ovflist(epi) clear epi's ovflist link slot
Convert ep_events_available(), ep_start_scan(), ep_done_scan(),
ep_poll_callback(), and ep_alloc_epitem() to use the wrappers. The
ovflist state-machine transitions are now named, not encoded in
sentinel comparisons, and the top-of-file "Ready-list state machine"
section is the single place that spells out the sentinel's meaning.
ep_alloc() keeps the raw "ep->ovflist = EP_UNACTIVE_PTR" init (no
concurrent access at that point) with an inline "not scanning"
comment, and the tfile_check_list sentinel is left alone -- it will
disappear entirely when the loop-check globals move into a
stack-allocated ep_ctl_ctx in a later commit.
Also rework ep_done_scan()'s for-loop: the combined initializer +
update clause that advanced nepi AND cleared epi->next in one step
was clever but hard to read; splitting the update into two
statements inside the body makes the epi_clear_ovflist() call
visible.
No functional change.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Link: https://patch.msgid.link/20260424-work-epoll-rework-v1-14-249ed00a20f3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
do_epoll_ctl() interleaved three concerns in one body: input
validation, the ep->mtx + epnested_mutex acquisition dance for
EPOLL_CTL_ADD on potentially-nested topologies, and the op dispatch
with final unlock. The middle concern is the error-prone one; the
error_tgt_fput label existed mainly to orchestrate it.
Extract the acquisition as ep_ctl_lock() and the release as
ep_ctl_unlock(). ep_ctl_lock() always takes ep->mtx and, for
EPOLL_CTL_ADD on a topology that can change, additionally runs the
loop / path check under epnested_mutex. The return value is a
ternary:
0 ep->mtx held.
1 ep->mtx AND epnested_mutex held (full-check mode).
-errno failure, no locks held.
The non-negative value doubles as the @full_check argument to
ep_insert() and as the argument to ep_ctl_unlock(), so the caller
neither needs an out-parameter nor a separate boolean:
full_check = ep_ctl_lock(ep, op, epfile, tfile, nonblock);
if (full_check < 0)
return full_check;
...
ep_ctl_unlock(ep, full_check);
ep_ctl_unlock() drops ep->mtx and, if full_check == 1, clears
tfile_check_list, bumps loop_check_gen, and drops epnested_mutex --
mirroring the old error_tgt_fput block.
With that in place do_epoll_ctl()'s preconditions become direct
returns (no locks held, nothing to clean up), the acquisition is a
single call, the op dispatch is unchanged, and the epilogue is a
single ep_ctl_unlock() before return. The error_tgt_fput label goes
away.
The two loop_check_gen bumps (one at the start of the full check,
one after) are preserved inside ep_ctl_lock() / ep_ctl_unlock(),
keeping the invariant that ep->gen stamps left on per-eventpoll
caches never equal loop_check_gen after the check completes.
No functional change.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Link: https://patch.msgid.link/20260424-work-epoll-rework-v1-13-249ed00a20f3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
ep_send_events()'s body covered two concerns: per-item work (PM
wakeup-source bookkeeping, re-poll, copy_to_user, level-trigger
re-queue, EPOLLONESHOT mask clear) and the scan-level accumulator
(maxevents cap, EFAULT preservation, txlist/rdllist splice).
Extract the per-item work as ep_deliver_event(), which returns a
tri-state int:
1 one event was delivered; caller advances the counter,
0 re-poll produced no caller-requested events (item drops
out of the ready list; a future callback will re-queue),
-EFAULT copy_to_user() faulted; item is already re-inserted at
the head of the txlist so ep_done_scan() splices it back
to rdllist.
The per-item comments (PM ordering, the "sole writer to rdllist"
invariant for the LT re-queue, the EFAULT semantics) move into
ep_deliver_event(). ep_send_events() reduces to the fatal-signal
short-circuit, scan bracket, and a short txlist walk that accumulates
the deliveries and preserves the "first error wins" EFAULT contract
(res = delivered only if no event was previously delivered; otherwise
the success count is returned and -EFAULT is reported on the next
call).
No functional change.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Link: https://patch.msgid.link/20260424-work-epoll-rework-v1-12-249ed00a20f3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
ep_clear_and_put()'s two-pass walk is the main way an ep file close
tears down its state, and the ordering between the passes is
load-bearing (see previous commit's docblock). Give each pass its
own function so the ordering is enforced by the call sequence in
ep_clear_and_put() rather than by convention inside one body.
ep_drain_pollwaits() carries out Pass 1: walk the rbtree and
ep_unregister_pollwait() each epi. The function-level comment names
it as Pass 1 and spells out the synchronization contract with
ep_poll_callback().
ep_drain_tree() carries out Pass 2: walk the rbtree and ep_remove()
each epi, capturing rb_next() before each erase. The comment names
it as Pass 2 and documents the hand-off with a concurrent
eventpoll_release_file() (removal path C).
ep_clear_and_put() keeps the poll-on-ep wakeup, ep->mtx bracketing,
and ep_put() + conditional ep_free(), and its docblock shrinks to
the high-level summary; the per-pass detail moved into the helpers.
No functional change.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Link: https://patch.msgid.link/20260424-work-epoll-rework-v1-11-249ed00a20f3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
ep_insert() was 130 lines and mixed four concerns in one body: user
quota charge and epitem allocation, attach-into-file-hlist plus
rbtree insert plus target-ep locking, reverse-path + EPOLLWAKEUP +
poll-queue install with rollback, and ready-list publication.
Factor the first two concerns into named helpers so the body reduces
to orchestration.
ep_alloc_epitem() charges the user's epoll_watches quota, allocates
a fresh epitem, and initializes its fields. On failure it returns
ERR_PTR(-ENOSPC) or ERR_PTR(-ENOMEM); on success the epi is not yet
linked into anything.
ep_register_epitem() installs @epi into @tfile's f_ep hlist and
@ep's rbtree, optionally chains @tfile onto tfile_check_list for the
path check, takes the tep->mtx nested lock for the epoll-watches-
epoll case, and finally takes the ep_get() reference that pairs
with ep_remove()'s ep_put() in ep_insert()'s error paths. On failure
it frees the epi and decrements epoll_watches to match
ep_alloc_epitem().
ep_insert()'s remaining body is the rollback-via-ep_remove() chain
(reverse_path_check, EPOLLWAKEUP source creation, ep_ptable_queue_proc
allocation) and the ready-list / wake publication. Remove a few
stale comments that duplicated function-level documentation or
described obvious code.
No functional change; rollback boundaries unchanged -- every error
path after ep_register_epitem() still calls ep_remove(), preserving
the ep->refcount invariant that keeps ep_remove()'s WARN_ON_ONCE safe.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Link: https://patch.msgid.link/20260424-work-epoll-rework-v1-10-249ed00a20f3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
ep_find_tfd() and get_epoll_tfile_raw_ptr() are only used when
CONFIG_KCMP=y. They implement the lookup side of the kcmp(2)
KCMP_EPOLL_TFD query. The helpers currently live between ep_find()
and ep_poll_callback(), interrupting the run of hot-path code
(callback, wait-queue setup, path check, insert, modify, send_events,
poll) with a feature-gated block.
Move the #ifdef CONFIG_KCMP block next to #ifdef CONFIG_COMPAT, which
is also a peripheral ABI extension. Hot-path code becomes a
contiguous span, and the userspace-adjacent extensions cluster at the
end of the file just before eventpoll_init().
Pure code movement; diff is 44 removed and 44 added, all within one
block. No functional change.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Link: https://patch.msgid.link/20260424-work-epoll-rework-v1-9-249ed00a20f3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
ep_remove_file() tears down the f_ep linkage that attach_epitem()
establishes, so the pair should look like one. Rename to
ep_attach_file() for the "ep_*" + subject symmetry and to match the
naming used elsewhere in the file (ep_insert, ep_modify, ep_remove,
ep_remove_file, ep_remove_epi, ep_unregister_pollwait).
Pure rename; no functional change.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Link: https://patch.msgid.link/20260424-work-epoll-rework-v1-8-249ed00a20f3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
epoll_mutex_lock() has three callers, all in do_epoll_ctl(), and every
one passes depth == 0. The argument has been dead since the helper was
introduced. Drop it. Because a zero subclass makes mutex_lock_nested()
equivalent to mutex_lock(), switch the blocking path to the simpler
primitive as well.
No functional change.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Link: https://patch.msgid.link/20260424-work-epoll-rework-v1-7-249ed00a20f3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
ep_refcount_dec_and_test() mirrors refcount_dec_and_test() verbatim,
which reads fine at a call site like
if (ep_refcount_dec_and_test(ep))
ep_free(ep);
but awkward at
WARN_ON_ONCE(ep_refcount_dec_and_test(ep));
and does not pair cleanly with ep_get(). Rename to the idiomatic
ep_put() and reword the kerneldoc to spell out the return-value
contract (caller is responsible for ep_free() iff the return is
true). Leave ep_put() as a bool-returning wrapper -- we cannot fold
ep_free() into it because ep_remove() calls it under ep->mtx and the
mutex would still be held when ep_free()'s mutex_destroy() ran (see
commit 8c2e52ebbe "eventpoll: don't decrement ep refcount while
still holding the ep mutex").
No functional change.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Link: https://patch.msgid.link/20260424-work-epoll-rework-v1-6-249ed00a20f3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
ep_clear_and_put() walks the rbtree twice: once to drain each epi's
pwqlist, then again to ep_remove() each entry. The split is
load-bearing -- fusing the passes into one loop would let a poll
callback still queued on some epi_i fire after epi_{i+k} has already
been freed -- but the previous comments described each pass in
isolation and did not explain the ordering invariant or the
cooperation with removal path C (eventpoll_release_file).
Add a function-level docblock that labels this as path B from the
top-of-file "Removal paths" section, names the two passes and the
ordering invariant, explains the pwqlist drain as synchronization
with in-flight ep_poll_callback() via whead->lock, describes the
C-path hand-off when epi_fget() returns NULL, and states the
ep->refcount invariant that keeps ep_remove()'s WARN_ON_ONCE safe
across the loop.
Also tighten the per-pass comments to one line each and fix the
minor grammar bug in the poll_wait release comment ("these file" ->
"poll-on-ep").
No functional change.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Link: https://patch.msgid.link/20260424-work-epoll-rework-v1-5-249ed00a20f3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Two comments drifted from the code they sit on.
epi_fget()'s block comment still referenced atomic_long_inc_not_zero,
which has been file_ref_get() for a while, and described only one of
the function's two roles: safe dereference of epi->ffd.file under
ep->mtx. Since commit a6dc643c69 ("eventpoll: fix ep_remove struct
eventpoll / struct file UAF") the refcount bump also serves as a pin
that blocks __fput() from starting, which is what lets ep_remove()
touch file->f_lock and file->f_ep without racing
eventpoll_release_file(). Update the block to name both roles and the
commit that introduced the pin role.
ep_remove_file()'s one-line "See eventpoll_release() for details"
pointed at an inline in include/linux/eventpoll.h but said nothing
about what those details were. Replace it with a short explanation:
we publish NULL so the eventpoll_release() fastpath can skip the slow
path, and this is safe because every f_ep writer either holds a pin
via epi_fget() or is __fput() itself.
Comment-only; no functional change.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Link: https://patch.msgid.link/20260424-work-epoll-rework-v1-4-249ed00a20f3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
ep_remove_wait_queue() and the POLLFREE branch of ep_poll_callback()
are the two halves of a release/acquire handshake that lets a
subsystem (binder, signalfd, ...) tear down a wait-queue head from
under a registered epitem. The existing local comments documented the
race but did not name the protocol or refer readers from one side to
the other. After the previous commit added a "POLLFREE handshake"
section to the top-of-file banner, these sites can point at the
banner and at each other.
Rework the two comment blocks so that each side is labelled
"acquire side" or "release side", references the banner, and
explains its role in the protocol. On the release side fuse the two
former comments into one narrative: list_del_init() tolerates a
second delete from a racing ep_remove_wait_queue(), and the
smp_store_release() is what lets that racing remover discover the
teardown.
Comment-only; no functional change.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Link: https://patch.msgid.link/20260424-work-epoll-rework-v1-3-249ed00a20f3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
The globals that support EPOLL_CTL_ADD's cycle and path-length checks
are scattered: epnested_mutex, loop_check_gen, inserting_into, and
tfile_check_list sit at the top of the file; path_count[] and
path_limits[] are declared inline with the path-check code further
down. Their interaction -- the "ep->gen == loop_check_gen" trigger in
do_epoll_ctl(), the two loop_check_gen++ bumps that sandwich a check,
the EP_UNACTIVE_PTR sentinel on tfile_check_list, the -ELOOP back-edge
detection via inserting_into -- is not documented anywhere.
The area has had three recent fixes (CVE-2025-38349, the unbounded
recursion fix, and the overflow fix) whose logic depends on these
invariants. Collect the description in one block alongside the
declarations, cross-reference the path_count[] declaration that lives
with the path-check code, and name the fix commits so future readers
can find the context.
Also add a short comment on struct epitems_head describing its
dual use (wrapper for non-epoll file->f_ep versus pointing into
&ep->refs for the epoll-watches-epoll case), which the old comment
on tfile_check_list had accidentally attached to the struct.
Comment-only; no functional change.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Link: https://patch.msgid.link/20260424-work-epoll-rework-v1-2-249ed00a20f3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
The existing ~40-line "LOCKING:" banner covered the three-level lock
hierarchy (epnested_mutex > ep->mtx > ep->lock) but nothing else.
Lifetime rules, the ready-list state machine, the three removal paths,
and the POLLFREE contract are implicit in the code. The recent UAF
series (a6dc643c69, 07712db808, 8c2e52ebbe, f2e467a482) rode
on invariants that were only implicit.
Codify them at the top of the file: the subsystem overview, the lock
hierarchy and its mutex_lock_nested() subclass convention (reworded
from the old banner), a field-protection table for struct eventpoll
and struct epitem that names the two faces of the rbn/rcu union (rbn
under ep->mtx while linked into ep->rbr; rcu touched only by
kfree_rcu(epi) on the free path), the ovflist sentinel encoding and
scan-flip invariants, the three removal paths (A ep_remove, B
ep_clear_and_put, C eventpoll_release_file) and the epi_fget() pin
that orchestrates A vs C, and the POLLFREE store-release /
load-acquire handshake.
No functional change.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Link: https://patch.msgid.link/20260424-work-epoll-rework-v1-1-249ed00a20f3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Driver core expects devices to be dynamically allocated and will, for
example, complain loudly if a device that lacks a release function
is ever freed.
Use root_device_register() to allocate and register the root device
instead of open coding using a static device.
While at it, drop the redundant additional reference taken at init.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Helge Deller <deller@gmx.de>
mlx5_ib_dev_res_srq_init() allocates two SRQs, s0 and s1. When
ib_create_srq() fails for s1, the error branch destroys s0 but falls
through and unconditionally assigns the freed s0 and the ERR_PTR s1 to
devr->s0 and devr->s1.
This leads to several problems: the lock-free fast path checks
"if (devr->s1) return 0;" and treats the ERR_PTR as already initialised;
users in mlx5_ib_create_qp() dereference the freed SRQ or ERR_PTR via
to_msrq(devr->s0)->msrq.srqn; and mlx5_ib_dev_res_cleanup() dereferences
the ERR_PTR and double-frees s0 on teardown.
Fix by adding the same `goto unlock` in the s1 failure path.
Cc: stable@vger.kernel.org
Fixes: 5895e70f2e ("IB/mlx5: Allocate resources just before first QP/SRQ is created")
Link: https://patch.msgid.link/r/SYBPR01MB7881E1E0970268BD69C0BA75AF2B2@SYBPR01MB7881.ausprd01.prod.outlook.com
Reported-by: Yuhao Jiang <danisjiang@gmail.com>
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
atomic_write_reply() at drivers/infiniband/sw/rxe/rxe_resp.c
unconditionally dereferences 8 bytes at payload_addr(pkt):
value = *(u64 *)payload_addr(pkt);
check_rkey() previously accepted an ATOMIC_WRITE request with pktlen ==
resid == 0 because the length validation only compared pktlen against
resid. A remote initiator that sets the RETH length to 0 therefore reaches
atomic_write_reply() with a zero-byte logical payload, and the responder
reads sizeof(u64) bytes from past the logical end of the packet into
skb->head tailroom, then writes those 8 bytes into the attacker's MR via
rxe_mr_do_atomic_write(). That is a remote disclosure of 4 bytes of kernel
tailroom per probe (the other 4 bytes are the packet's own trailing ICRC).
IBA oA19-28 defines ATOMIC_WRITE as exactly 8 bytes. Anything else is
protocol-invalid. Hoist a strict length check into check_rkey() so the
responder never reaches the unchecked dereference, and keep the existing
WRITE-family length logic for the normal RDMA WRITE path.
Reproduced on mainline with an unmodified rxe driver: a sustained
zero-length ATOMIC_WRITE probe repeatedly leaks adjacent skb head-buffer
bytes into the attacker's MR, including recognisable kernel strings and
partial kernel-direct-map pointer words. With this patch applied the
responder rejects the PDU and the MR stays all-zero.
Cc: stable@vger.kernel.org
Fixes: 034e285f8b ("RDMA/rxe: Make responder support atomic write on RC service")
Link: https://patch.msgid.link/r/20260418162141.3610201-1-michael.bommarito@gmail.com
Assisted-by: Claude:claude-opus-4-7
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Even after applying commit 7244491dab ("RDMA/rxe: Validate pad and ICRC
before payload_size() in rxe_rcv"), a single unauthenticated UDP packet
can still trigger panic. That patch handled payload_size() underflow only
for valid opcodes with short packets, not for packets carrying an unknown
opcode. The unknown-opcode OOB read described below predates that commit
and reaches back to the initial Soft RoCE driver.
The check added there reads
pkt->paylen < header_size(pkt) + bth_pad(pkt) + RXE_ICRC_SIZE
where header_size(pkt) expands to rxe_opcode[pkt->opcode].length. The
rxe_opcode[] array has 256 entries but is only populated for defined IB
opcodes; any other entry (for example opcode 0xff) is zero-initialized, so
length == 0 and the check degenerates to
pkt->paylen < 0 + bth_pad(pkt) + RXE_ICRC_SIZE
which does not constrain pkt->paylen enough. rxe_icrc_hdr() then computes
rxe_opcode[pkt->opcode].length - RXE_BTH_BYTES
which underflows when length == 0 and passes a huge value to rxe_crc32(),
causing an out-of-bounds read of the skb payload.
Reproduced on v7.0-rc7 with that fix applied, QEMU/KVM with
CONFIG_RDMA_RXE=y and CONFIG_KASAN=y, after
rdma link add rxe0 type rxe netdev eth0
A single 48-byte UDP packet to port 4791 with BTH opcode=0xff and
QPN=IB_MULTICAST_QPN triggers:
BUG: KASAN: slab-out-of-bounds in crc32_le+0x115/0x170
Read of size 1 at addr ...
The buggy address is located 0 bytes to the right of
allocated 704-byte region
Call Trace:
crc32_le+0x115/0x170
rxe_icrc_hdr.isra.0+0x226/0x300
rxe_icrc_check+0x13f/0x3a0
rxe_rcv+0x6e1/0x16e0
rxe_udp_encap_recv+0x20a/0x320
udp_queue_rcv_one_skb+0x7ed/0x12c0
Subsequent packets with the same shape fault on unmapped memory and panic
the kernel. The trigger requires only module load and "rdma link add"; no
QP, no connection, and no authentication.
Fix this by rejecting packets whose opcode has no rxe_opcode[] entry,
detected via the zero mask or zero length, before any length arithmetic
runs.
Cc: stable@vger.kernel.org
Fixes: 8700e3e7c4 ("Soft RoCE driver")
Link: https://patch.msgid.link/r/20260414111555.3386793-1-michael.bommarito@gmail.com
Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Pull MD fixes from Yu Kuai:
"Bug Fixes:
- Fix a raid5 UAF on IO across the reshape position.
- Avoid failing RAID1/RAID10 devices for invalid IO errors.
- Fix RAID10 divide-by-zero when far_copies is zero.
- Restore bitmap grow through sysfs.
Cleanups:
- Use mddev_is_dm() instead of open-coding gendisk checks.
- Use ATTRIBUTE_GROUPS() for md default sysfs attributes.
- Replace open-coded wait loops with wait_event helpers."
* tag 'md-7.1-20260428' of https://git.kernel.org/pub/scm/linux/kernel/git/mdraid/linux:
md: use ATTRIBUTE_GROUPS() for md default sysfs attributes
md: use mddev_is_dm() instead of open-coding gendisk checks
md/raid1: replace wait loop with wait_event_idle() in raid1_write_request()
md/md-bitmap: add a none backend for bitmap grow
md/md-bitmap: split bitmap sysfs groups
md: factor bitmap creation away from sysfs handling
md: use mddev_lock_nointr() in mddev_suspend_and_lock_nointr()
md: replace wait loop with wait_event() in md_handle_request()
md/raid10: fix divide-by-zero in setup_geo() with zero far_copies
md/raid1,raid10: don't fail devices for invalid IO errors
MAINTAINERS: Add Xiao Ni as md/raid reviewer
md/raid5: Fix UAF on IO across the reshape position
The current teardown logic for dd->pio_map and dd->sdma_map frees the
structures while they might still be accessed by RCU readers. Although the
pointer is nulled under a spinlock, the memory is reclaimed before waiting
for the grace period to end.
This patch fixes the sequence by:
1. Extracting the pointer under the lock.
2. Clearing the RCU-protected pointer.
3. Waiting for readers to finish with synchronize_rcu().
4. Finally freeing the memory.
Fixes: 7724105686 ("IB/hfi1: add driver files")
Link: https://patch.msgid.link/r/20260206050836.5890-1-lirongqing@baidu.com
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Table 7-121 in datasheet says we have to set register 0xc6
to value 0x10 before CLK_O_SEL can be modified. No more infos
about this field found in datasheet. With this fix, setting
of CLK_O_SEL field in IO_MUX_CFG register worked through dts
property "ti,clk-output-sel" on a DP83869HMRGZR.
Signed-off-by: Heiko Schocher <hs@nabladev.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Fixes: 01db923e83 ("net: phy: dp83869: Add TI dp83869 phy")
Link: https://patch.msgid.link/20260425031339.3318-1-hs@nabladev.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
memfd_luo_retrieve_folios() initialises err to -EIO, but the per-iteration
calls to mem_cgroup_charge(), shmem_add_to_page_cache() and
shmem_inode_acct_blocks() reuse and overwrite err. Once any iteration
completes successfully, err becomes zero.
If a later iteration's kho_restore_folio() returns NULL, the failure path
jumps to put_folios without resetting err, so the function returns 0.
The caller memfd_luo_retrieve() then takes the success path, sets
args->file and reports the restore as successful, leaving userspace with
a partially populated memfd and no indication that anything went wrong.
Set err to -EIO in the kho_restore_folio() failure branch so the error
is propagated to the caller.
Signed-off-by: David Carlier <devnexen@gmail.com>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Fixes: b3749f174d ("mm: memfd_luo: allow preserving memfd")
Link: https://patch.msgid.link/20260415052300.362539-1-devnexen@gmail.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
kho_fill_kimage() unconditionally populates the kimage with KHO
metadata for every kexec image type. When the image is a crash kernel,
this can be problematic as the crash kernel can run in a small reserved
region and the KHO scratch areas can sit outside it.
The crash kernel then faults during kho_memory_init() when it
tries phys_to_virt() on the KHO FDT address:
Unable to handle kernel paging request at virtual address xxxxxxxx
...
fdt_offset_ptr+...
fdt_check_node_offset_+...
fdt_first_property_offset+...
fdt_get_property_namelen_+...
fdt_getprop+...
kho_memory_init+...
mm_core_init+...
start_kernel+...
kho_locate_mem_hole() already skips KHO logic for KEXEC_TYPE_CRASH
images, but kho_fill_kimage() was missing the same guard. As
kho_fill_kimage() is the single point that populates image->kho.fdt
and image->kho.scratch, fixing it here is sufficient for both arm64
and x86 as the FDT and boot_params path are bailing out when these
fields are unset.
Fixes: d7255959b6 ("kho: allow kexec load before KHO finalization")
Signed-off-by: Evangelos Petrongonas <epetron@amazon.de>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260410011609.1103-1-epetron@amazon.de
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
The Smatch reported a warning in __ntfs_bitmap_set_bits_in_run():
"warn: passing a valid pointer to 'PTR_ERR'"
This occurs because the 'folio' variable might contain a valid pointer
when jumping to the 'rollback' label, specifically when 'cnt <= 0' is
detected during the subsequent page mapping loop. In such cases,
calling PTR_ERR(folio) is incorrect as it does not contain an error
code.
Fix this by introducing an explicit 'err' variable to track the error
status. This ensures that the rollback logic and the return value
consistently use a proper error code regardless of the state of the
folio pointer.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
In case of a Secure-Storage-Access exception the effective aka virtual
address which caused the exception is contained within the TEID.
do_secure_storage_access() incorrectly uses phys_to_folio() instead of
virt_to_folio() to translate the virtual address to the corresponding
folio.
Fix this by using virt_to_folio() instead of phys_to_folio().
Fixes: 084ea4d611 ("s390/mm: add (non)secure page access exceptions handlers")
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Remove the SCLP_OFB Kconfig option and enable the guarded code
unconditionally. This guards only a few lines of code, so the impact is
very low while at the same time this reduces the large number of Kconfig
options.
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Add myself as co-maintainer for s390/pci, replacing Gerald Schaefer who
has moved his focus to s390/mm. Thank you Gerald!
Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
Acked-by: Niklas Schnelle <schnelle@linux.ibm.com>
Acked-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
debug_input_flush_fn() always copies one byte from the userspace buffer
with copy_from_user() regardless of the supplied write length. A
zero-length write therefore reads one byte beyond the caller's buffer.
If the stale byte happens to be '-' or a digit the debug log is
silently flushed. With an unmapped buffer the call returns -EFAULT.
Reject zero-length writes before copying from userspace.
Cc: stable@vger.kernel.org # v5.10+
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
debug_get_user_string() duplicates the userspace buffer with
memdup_user_nul() and then unconditionally looks at buffer[user_len - 1]
to strip a trailing newline.
A zero-length write reaches this helper unchanged, so the newline trim
reads before the start of the allocated buffer.
Reject empty writes before accessing the last input byte.
Fixes: 66a464dbc8 ("[PATCH] s390: debug feature changes")
Cc: stable@vger.kernel.org
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Tested-by: Vasily Gorbik <gor@linux.ibm.com>
Link: https://lore.kernel.org/r/20260417073530.96002-1-pengpeng@iscas.ac.cn
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Add a real none bitmap backend that exposes the common bitmap sysfs
group and use it to keep bitmap/location available when an array has no
bitmap.
Then switch the bitmap location sysfs path to move only between none
and the classic bitmap backend, using the no-sysfs bitmap helpers while
merging or unmerging the internal bitmap sysfs group.
This restores mdadm --grow bitmap addition through bitmap/location.
Fixes: fb8cc3b0d9 ("md/md-bitmap: delay registration of bitmap_ops until creating bitmap")
Reviewed-by: Su Yue <glass.su@suse.com>
Link: https://lore.kernel.org/r/20260425024615.1696892-4-yukuai@fnnas.com
Signed-off-by: Yu Kuai <yukuai@fnnas.com>
Split the classic bitmap sysfs files into a common bitmap group with
the location attribute and a separate internal bitmap group for the
remaining files.
At the same time, convert bitmap operations from a single sysfs group
to a sysfs group array so backends can share part of their sysfs
layout while adding backend-specific attributes separately.
Switch the bitmap sysfs helpers to use sysfs_update_groups() for the
add and update path, and remove groups in reverse order so shared named
groups are unmerged before the last group removes the directory.
Also make bitmap operation lookup depend only on the currently selected
bitmap id matching the installed backend. This prepares the lookup path
for a later registered none backend.
Reviewed-by: Su Yue <glass.su@suse.com>
Link: https://lore.kernel.org/r/20260425024615.1696892-3-yukuai@fnnas.com
Signed-off-by: Yu Kuai <yukuai@fnnas.com>
Factor bitmap creation and destruction into helpers that do not touch
bitmap sysfs registration.
This prepares the bitmap sysfs rework so callers such as the sysfs
bitmap location path can create or destroy a bitmap backend without
coupling that to sysfs group lifetime management.
Reviewed-by: Su Yue <glass.su@suse.com>
Link: https://lore.kernel.org/r/20260425024615.1696892-2-yukuai@fnnas.com
Signed-off-by: Yu Kuai <yukuai@fnnas.com>
This keeps mddev locking consistent and ensures that any future changes
to locking behavior are done through the wrapper.
Signed-off-by: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
Link: https://lore.kernel.org/r/20260415140319.376578-3-abd.masalkhi@gmail.com
Signed-off-by: Yu Kuai <yukuai@fnnas.com>
setup_geo() extracts near_copies (nc) and far_copies (fc) from the
user-provided layout parameter without checking for zero. When fc=0
with the "improved" far set layout selected, 'geo->far_set_size =
disks / fc' triggers a divide-by-zero.
Validate nc and fc immediately after extraction, returning -1 if
either is zero.
Fixes: 475901aff1 ("MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1)")
Cc: stable@vger.kernel.org
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Link: https://lore.kernel.org/linux-raid/SYBPR01MB7881A5E2556806CC1D318582AF232@SYBPR01MB7881.ausprd01.prod.outlook.com
Signed-off-by: Yu Kuai <yukuai@fnnas.com>
BLK_STS_INVAL indicates the IO request itself was invalid, not that the
device has failed. When raid1 treats this as a device error, it retries
on alternate mirrors which fail the same way, eventually exceeding the
read error threshold and removing the device from the array.
This happens when stacking configurations bypass bio_split_to_limits()
in the IO path: dm-raid calls md_handle_request() directly without going
through md_submit_bio(), skipping the alignment validation that would
otherwise reject invalid bios early. The invalid bio reaches the
lower block layers, which fail the bio with BLK_STS_INVAL, and raid1
wrongly interprets this as a device failure.
Add BLK_STS_INVAL to raid1_should_handle_error() so that invalid IO
errors are propagated back to the caller rather than triggering device
removal. This is consistent with the previous kernel behavior when
alignment checks were done earlier in the direct-io path.
Fixes: 5ff3f74e14 ("block: simplify direct io validity check")
Reported-by: Tomáš Trnka <trnka@scm.com>
Closes: https://lore.kernel.org/linux-block/2982107.4sosBPzcNG@electra/
Signed-off-by: Keith Busch <kbusch@kernel.org>
Tested-by: Tomáš Trnka <trnka@scm.com>
Link: https://lore.kernel.org/r/20260416140345.3872265-1-kbusch@meta.com
Signed-off-by: Yu Kuai <yukuai@fnnas.com>
I've been actively involved in the md subsystem, contributing bug
fixes, performance improvements, and participating in code reviews.
I will help improve patch review coverage and response time.
Signed-off-by: Xiao Ni <xiao@kernel.org>
Link: https://lore.kernel.org/r/20260414022956.48271-1-xiaoraid25@gmail.com
Signed-off-by: Yu Kuai <yukuai@fnnas.com>
If make_stripe_request() returns STRIPE_WAIT_RESHAPE,
raid5_make_request() will free the cloned bio. But raid5_make_request()
can call make_stripe_request() multiple times, writing to the various
stripes. If that bio got added to the toread or towrite lists of a
stripe disk in an earlier call to make_stripe_request(), then it's not
safe to just free the bio if a later part of it is found to cross the
reshape position. Doing so can lead to a UAF error, when bio_endio()
is called on the bio for the earlier stripes.
Instead, raid5_make_request() needs to wait until all parts of the bio
have called bio_endio(). To do this, bios that cross the reshape
position while the reshape can't make progress are flagged as needing to
wait for all parts to complete. When raid5_make_request() has a bio that
failed make_stripe_request() with STRIPE_WAIT_RESHAPE, it sets
bi->bi_private to a completion struct and waits for completion after
ending the bio. When the bio_endio() is called for the last time on a
clone bio with bi->bi_private set, it wakes up the waiter. This
guarantees that raid5_make_request() doesn't return until the cloned bio
needing a retry for io across the reshape boundary is safely cleaned up.
There is a simple reproducer available at [1]. Compile the kernel with
KASAN for more useful reporting when the error is triggered (this is not
necessary to see the bug).
[1] https://gist.github.com/bmarzins/e48598824305cf2171289e47d7241fa5
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Reviewed-by: Xiao Ni <xni@redhat.com>
Link: https://lore.kernel.org/r/20260408043548.1695157-1-bmarzins@redhat.com
Signed-off-by: Yu Kuai <yukuai@fnnas.com>
Fix the horizontal bit position when rotating a glyph by 180°. The
original code in rotate_ud() rounded the value in width up to a
multiple of 8, aka the bit pitch, and calculated the rotated pixel
from that value. The new code stores the glyph's pitch in bit_pitch,
but fails to update the rotated pixel's output accordingly. Simply
replacing the variable does this.
The bug can be reproduced by setting a font with an unaligned width,
such as sun12x22, like this:
setfont sun12x22
echo 2 > /sys/class/graphics/fbcon/rotate
Without the fix, the font looks distorted.
Fixes: a30e9e6b01 ("lib/fonts: Refactor glyph-rotation helpers")
Closes: https://lore.gitlab.freedesktop.org/drm-ai-reviews/review-patch7-20260407092555.58816-8-tzimmermann@suse.de/
Cc: dri-devel@lists.freedesktop.org
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Remove duplicate inclusion of linux/module.h in fb_defio.c to clean up
redundant code.
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Signed-off-by: Helge Deller <deller@gmx.de>
Correct all kernel-doc warnings:
- fix a typedef kernel-doc comment
- mark a list_head as private
- use Returns: for function return values
Warning: include/video/imx-ipu-image-convert.h:31 struct member 'list' not
described in 'ipu_image_convert_run'
Warning: include/video/imx-ipu-image-convert.h:40 function parameter
'ipu_image_convert_cb_t' not described in 'void'
Warning: include/video/imx-ipu-image-convert.h:40 expecting prototype for
ipu_image_convert_cb_t(). Prototype was for void() instead
Warning: include/video/imx-ipu-image-convert.h:66 No description found for
return value of 'ipu_image_convert_verify'
Warning: include/video/imx-ipu-image-convert.h:90 No description found for
return value of 'ipu_image_convert_prepare'
Warning: include/video/imx-ipu-image-convert.h:125 No description found for
return value of 'ipu_image_convert_queue'
Warning: include/video/imx-ipu-image-convert.h:163 No description found for
return value of 'ipu_image_convert'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Currently, mctp_i2c_get_tx_flow_state() is called before the packet length
sanity check. This function marks a new flow as active in the MCTP core.
If the sanity check fails, mctp_i2c_xmit() returns early without calling
mctp_i2c_lock_nest(). This results in a mismatched locking state: the
flow is active, but the I2C bus lock was never acquired for it.
When the flow is later released, mctp_i2c_release_flow() will see the
active state and queue an unlock marker. The TX thread will then
decrement midev->i2c_lock_count from 0, causing it to underflow to -1.
This underflow permanently breaks the driver's locking logic, allowing
future transmissions to occur without holding the I2C bus lock, leading
to bus collisions and potential hardware hangs.
Move the mctp_i2c_get_tx_flow_state() call to after the length sanity
check to ensure we only transition the flow state if we are actually
going to proceed with the transmission and locking.
Fixes: f5b8abf9fc ("mctp i2c: MCTP I2C binding driver")
Signed-off-by: William A. Kennington III <william@wkennington.com>
Acked-by: Jeremy Kerr <jk@codeconstruct.com.au>
Link: https://patch.msgid.link/20260423074741.201460-1-william@wkennington.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
If kzalloc fails, the function returns -ENOMEM without calling
efivar_unlock(). Since open() returned an error, the calling site
in pstore_get_backend_records() won't call the close() function, so
the lock is never released. Thus drop the lock in case of errors here.
Fixes: 859748255b ("efi: pstore: Omit efivars caching EFI varstore access layer")
Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Use QSTR() and drop strlen() in efivarfs_alloc_dentry().
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
