commit 355b985537 upstream.
net_hash_mix() currently uses kernel address of a struct net,
and is used in many places that could be used to reveal this
address to a patient attacker, thus defeating KASLR, for
the typical case (initial net namespace, &init_net is
not dynamically allocated)
I believe the original implementation tried to avoid spending
too many cycles in this function, but security comes first.
Also provide entropy regardless of CONFIG_NET_NS.
Fixes: 0b4419162a ("netns: introduce the net_hash_mix "salt" for hashes")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Amit Klein <aksecurity@gmail.com>
Reported-by: Benny Pinkas <benny@pinkas.net>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 5f3e2bf008 upstream.
Some TCP peers announce a very small MSS option in their SYN and/or
SYN/ACK messages.
This forces the stack to send packets with a very high network/cpu
overhead.
Linux has enforced a minimal value of 48. Since this value includes
the size of TCP options, and that the options can consume up to 40
bytes, this means that each segment can include only 8 bytes of payload.
In some cases, it can be useful to increase the minimal value
to a saner value.
We still let the default to 48 (TCP_MIN_SND_MSS), for compatibility
reasons.
Note that TCP_MAXSEG socket option enforces a minimal value
of (TCP_MIN_MSS). David Miller increased this minimal value
in commit c39508d6f1 ("tcp: Make TCP_MAXSEG minimum more correct.")
from 64 to 88.
We might in the future merge TCP_MIN_SND_MSS and TCP_MIN_MSS.
CVE-2019-11479 -- tcp mss hardcoded to 48
Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Jonathan Looney <jtl@netflix.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Bruce Curtis <brucec@netflix.com>
Cc: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[Salvatore Bonaccorso: Backport for context changes in 4.9.168]
[bwh: Backported to 3.16: Make the sysctl global, consistent with
net.ipv4.tcp_base_mss]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 3b4929f65b upstream.
Jonathan Looney reported that TCP can trigger the following crash
in tcp_shifted_skb() :
BUG_ON(tcp_skb_pcount(skb) < pcount);
This can happen if the remote peer has advertized the smallest
MSS that linux TCP accepts : 48
An skb can hold 17 fragments, and each fragment can hold 32KB
on x86, or 64KB on PowerPC.
This means that the 16bit witdh of TCP_SKB_CB(skb)->tcp_gso_segs
can overflow.
Note that tcp_sendmsg() builds skbs with less than 64KB
of payload, so this problem needs SACK to be enabled.
SACK blocks allow TCP to coalesce multiple skbs in the retransmit
queue, thus filling the 17 fragments to maximal capacity.
CVE-2019-11477 -- u16 overflow of TCP_SKB_CB(skb)->tcp_gso_segs
Backport notes, provided by Joao Martins <joao.m.martins@oracle.com>
v4.15 or since commit 737ff31456 ("tcp: use sequence distance to
detect reordering") had switched from the packet-based FACK tracking and
switched to sequence-based.
v4.14 and older still have the old logic and hence on
tcp_skb_shift_data() needs to retain its original logic and have
@fack_count in sync. In other words, we keep the increment of pcount with
tcp_skb_pcount(skb) to later used that to update fack_count. To make it
more explicit we track the new skb that gets incremented to pcount in
@next_pcount, and we get to avoid the constant invocation of
tcp_skb_pcount(skb) all together.
Fixes: 832d11c5cd ("tcp: Try to restore large SKBs while SACK processing")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jonathan Looney <jtl@netflix.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Bruce Curtis <brucec@netflix.com>
Cc: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[Salvatore Bonaccorso: Adjust for context changes to backport to
4.9.168]
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit caa415270c upstream.
nh_exceptions is effectively used under rcu, but lacks proper
barriers. Between kzalloc() and setting of nh->nh_exceptions(),
we need a proper memory barrier.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 4895c771c7 ("ipv4: Add FIB nexthop exceptions.")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 04f81f0154 upstream.
Using the IPCB() macro to get the IPv4 options is convenient, but
unfortunately NetLabel often needs to examine the CIPSO option outside
of the scope of the IP layer in the stack. While historically IPCB()
worked above the IP layer, due to the inclusion of the inet_skb_param
struct at the head of the {tcp,udp}_skb_cb structs, recent commit
971f10ec ("tcp: better TCP_SKB_CB layout to reduce cache line misses")
reordered the tcp_skb_cb struct and invalidated this IPCB() trick.
This patch fixes the problem by creating a new function,
cipso_v4_optptr(), which locates the CIPSO option inside the IP header
without calling IPCB(). Unfortunately, this isn't as fast as a simple
lookup so some additional tweaks were made to limit the use of this
new function.
Reported-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit af7d6cce53 upstream.
Since commit 5aad1de5ea ("ipv4: use separate genid for next hop
exceptions"), exceptions get deprecated separately from cached
routes. In particular, administrative changes don't clear PMTU anymore.
As Stefano described in commit e9fa1495d7 ("ipv6: Reflect MTU changes
on PMTU of exceptions for MTU-less routes"), the PMTU discovered before
the local MTU change can become stale:
- if the local MTU is now lower than the PMTU, that PMTU is now
incorrect
- if the local MTU was the lowest value in the path, and is increased,
we might discover a higher PMTU
Similarly to what commit e9fa1495d7 did for IPv6, update PMTU in those
cases.
If the exception was locked, the discovered PMTU was smaller than the
minimal accepted PMTU. In that case, if the new local MTU is smaller
than the current PMTU, let PMTU discovery figure out if locking of the
exception is still needed.
To do this, we need to know the old link MTU in the NETDEV_CHANGEMTU
notifier. By the time the notifier is called, dev->mtu has been
changed. This patch adds the old MTU as additional information in the
notifier structure, and a new call_netdevice_notifiers_u32() function.
Fixes: 5aad1de5ea ("ipv4: use separate genid for next hop exceptions")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16:
- Pass net_device argument to call_netdevice_notifiers_info()
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 455f05ecd2 upstream.
syzbot reported that we reinitialize an active delayed
work in vsock_stream_connect():
ODEBUG: init active (active state 0) object type: timer_list hint:
delayed_work_timer_fn+0x0/0x90 kernel/workqueue.c:1414
WARNING: CPU: 1 PID: 11518 at lib/debugobjects.c:329
debug_print_object+0x16a/0x210 lib/debugobjects.c:326
The pattern is apparently wrong, we should only initialize
the dealyed work once and could repeatly schedule it. So we
have to move out the initializations to allocation side.
And to avoid confusion, we can split the shared dwork
into two, instead of re-using the same one.
Fixes: d021c34405 ("VSOCK: Introduce VM Sockets")
Reported-by: <syzbot+8a9b1bd330476a4f3db6@syzkaller.appspotmail.com>
Cc: Andy king <acking@vmware.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Jorgen Hansen <jhansen@vmware.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 9ce7bc036a upstream.
It is a waste of memory to use a full "struct netns_sysctl_ipv6"
while only one pointer is really used, considering netns_sysctl_ipv6
keeps growing.
Also, since "struct netns_frags" has cache line alignment,
it is better to move the frags_hdr pointer outside, otherwise
we spend a full cache line for this pointer.
This saves 192 bytes of memory per netns.
Fixes: c038a767cd ("ipv6: add a new namespace for nf_conntrack_reasm")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit b1993a2de1 upstream.
syzbot reported :
BUG: KMSAN: uninit-value in rtnh_ok include/net/nexthop.h:11 [inline]
BUG: KMSAN: uninit-value in fib_count_nexthops net/ipv4/fib_semantics.c:469 [inline]
BUG: KMSAN: uninit-value in fib_create_info+0x554/0x8d20 net/ipv4/fib_semantics.c:1091
@remaining is an integer, coming from user space.
If it is negative we want rtnh_ok() to return false.
Fixes: 4e902c5741 ("[IPv4]: FIB configuration using struct fib_config")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 8eb1a8590f upstream.
This fixes the following kernel-doc warning:
./include/net/dst.h:366: warning: Function parameter or member 'net' not described in 'skb_tunnel_rx'
Fixes: ea23192e8e ("tunnels: harmonize cleanup done on skb on rx path")
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit d52e5a7e7c upstream.
Prior to the rework of PMTU information storage in commit
2c8cec5c10 ("ipv4: Cache learned PMTU information in inetpeer."),
when a PMTU event advertising a PMTU smaller than
net.ipv4.route.min_pmtu was received, we would disable setting the DF
flag on packets by locking the MTU metric, and set the PMTU to
net.ipv4.route.min_pmtu.
Since then, we don't disable DF, and set PMTU to
net.ipv4.route.min_pmtu, so the intermediate router that has this link
with a small MTU will have to drop the packets.
This patch reestablishes pre-2.6.39 behavior by splitting
rtable->rt_pmtu into a bitfield with rt_mtu_locked and rt_pmtu.
rt_mtu_locked indicates that we shouldn't set the DF bit on that path,
and is checked in ip_dont_fragment().
One possible workaround is to set net.ipv4.route.min_pmtu to a value low
enough to accommodate the lowest MTU encountered.
Fixes: 2c8cec5c10 ("ipv4: Cache learned PMTU information in inetpeer.")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 35d889d10b upstream.
When we exceed current packets limit and we have more than one
segment in the list returned by skb_gso_segment(), netem drops
only the first one, skipping the rest, hence kmemleak reports:
unreferenced object 0xffff880b5d23b600 (size 1024):
comm "softirq", pid 0, jiffies 4384527763 (age 2770.629s)
hex dump (first 32 bytes):
00 80 23 5d 0b 88 ff ff 00 00 00 00 00 00 00 00 ..#]............
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000d8a19b9d>] __alloc_skb+0xc9/0x520
[<000000001709b32f>] skb_segment+0x8c8/0x3710
[<00000000c7b9bb88>] tcp_gso_segment+0x331/0x1830
[<00000000c921cba1>] inet_gso_segment+0x476/0x1370
[<000000008b762dd4>] skb_mac_gso_segment+0x1f9/0x510
[<000000002182660a>] __skb_gso_segment+0x1dd/0x620
[<00000000412651b9>] netem_enqueue+0x1536/0x2590 [sch_netem]
[<0000000005d3b2a9>] __dev_queue_xmit+0x1167/0x2120
[<00000000fc5f7327>] ip_finish_output2+0x998/0xf00
[<00000000d309e9d3>] ip_output+0x1aa/0x2c0
[<000000007ecbd3a4>] tcp_transmit_skb+0x18db/0x3670
[<0000000042d2a45f>] tcp_write_xmit+0x4d4/0x58c0
[<0000000056a44199>] tcp_tasklet_func+0x3d9/0x540
[<0000000013d06d02>] tasklet_action+0x1ca/0x250
[<00000000fcde0b8b>] __do_softirq+0x1b4/0x5a3
[<00000000e7ed027c>] irq_exit+0x1e2/0x210
Fix it by adding the rest of the segments, if any, to skb 'to_free'
list. Add new __qdisc_drop_all() and qdisc_drop_all() functions
because they can be useful in the future if we need to drop segmented
GSO packets in other places.
Fixes: 6071bd1aa1 ("netem: Segment GSO packets on enqueue")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16:
- The reshape_fail operation still exists, so keep calling it here if the
skb did not require segmentation
- We don't have a to_free list, so free directly in qdisc_drop_all()
- Open-code qdisc_qstats_drop()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 657308f73e upstream.
Similar to the ancient commit a5fe8e7695 ("regulatory: add NUL
to alpha2"), add another byte to alpha2 in the request struct so
that when we use nla_put_string(), we don't overrun anything.
Fixes: 73d54c9e74 ("cfg80211: add regulatory netlink multicast group")
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 15f35d49c9 upstream.
Since UDP-Lite is always using checksum, the following path is
triggered when calculating pseudo header for it:
udp4_csum_init() or udp6_csum_init()
skb_checksum_init_zero_check()
__skb_checksum_validate_complete()
The problem can appear if skb->len is less than CHECKSUM_BREAK. In
this particular case __skb_checksum_validate_complete() also invokes
__skb_checksum_complete(skb). If UDP-Lite is using partial checksum
that covers only part of a packet, the function will return bad
checksum and the packet will be dropped.
It can be fixed if we skip skb_checksum_init_zero_check() and only
set the required pseudo header checksum for UDP-Lite with partial
checksum before udp4_csum_init()/udp6_csum_init() functions return.
Fixes: ed70fcfcee ("net: Call skb_checksum_init in IPv4")
Fixes: e4f45b7f40 ("net: Call skb_checksum_init in IPv6")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 9302d7bb0c upstream.
sctp_v4_map_v6 was subtly writing and reading from members
of a union in a way the clobbered data it needed to read before
it read it.
Zeroing the v6 flowinfo overwrites the v4 sin_addr with 0, meaning
that every place that calls sctp_v4_map_v6 gets ::ffff:0.0.0.0 as the
result.
Reorder things to guarantee correct behaviour no matter what the
union layout is.
This impacts user space clients that open an IPv6 SCTP socket and
receive IPv4 connections. Prior to 299ee user space would see a
sockaddr with AF_INET and a correct address, after 299ee the sockaddr
is AF_INET6, but the address is wrong.
Fixes: 299ee123e1 (sctp: Fixup v4mapped behaviour to comply with Sock API)
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 51a1aaa631 upstream.
When creating a new radio on the fly, hwsim allows this
to be done with an arbitrary number of channels, but
cfg80211 only supports a limited number of simultaneous
channels, leading to a warning.
Fix this by validating the number - this requires moving
the define for the maximum out to a visible header file.
Reported-by: syzbot+8dd9051ff19940290931@syzkaller.appspotmail.com
Fixes: b59ec8dd43 ("mac80211_hwsim: fix number of channels in interface combinations")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
[bwh: Backported to 3.16:
- Test chans intead of param.channels
- GENL_SET_ERR_MSG() is not available
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit acf568ee85 upstream.
This is an old bugbear of mine:
https://www.mail-archive.com/netdev@vger.kernel.org/msg03894.html
By crafting special packets, it is possible to cause recursion
in our kernel when processing transport-mode packets at levels
that are only limited by packet size.
The easiest one is with DNAT, but an even worse one is where
UDP encapsulation is used in which case you just have to insert
an UDP encapsulation header in between each level of recursion.
This patch avoids this problem by reinjecting tranport-mode packets
through a tasklet.
Fixes: b05e106698 ("[IPV4/6]: Netfilter IPsec input hooks")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
[bwh: Backported to 3.16:
- netfilter finish callbacks only receive an sk_buff pointer
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 8afa10cbe2 upstream.
Check the qmin & qmax values doesn't overflow for the given Wlog value.
Check that qmin <= qmax.
Fixes: a783474591 ("[PKT_SCHED]: Generic RED layer")
Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 5c47220342 upstream.
Do not allow delta value to be zero since it is used as a divisor.
Fixes: 8af2a218de ("sch_red: Adaptative RED AQM")
Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit af2697a027 upstream.
Now sctp_csum_xxx doesn't really match the param types of these common
csum apis. As sctp_csum_xxx is defined in sctp/checksum.h, many sparse
errors occur when make C=2 not only with M=net/sctp but also with other
modules that include this header file.
This patch is to force them fit in csum apis with the right types.
Fixes: e6d8b64b34 ("net: sctp: fix and consolidate SCTP checksumming code")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 299ee123e1 upstream.
The SCTP socket extensions API document describes the v4mapping option as
follows:
8.1.15. Set/Clear IPv4 Mapped Addresses (SCTP_I_WANT_MAPPED_V4_ADDR)
This socket option is a Boolean flag which turns on or off the
mapping of IPv4 addresses. If this option is turned on, then IPv4
addresses will be mapped to V6 representation. If this option is
turned off, then no mapping will be done of V4 addresses and a user
will receive both PF_INET6 and PF_INET type addresses on the socket.
See [RFC3542] for more details on mapped V6 addresses.
This description isn't really in line with what the code does though.
Introduce addr_to_user (renamed addr_v4map), which should be called
before any sockaddr is passed back to user space. The new function
places the sockaddr into the correct format depending on the
SCTP_I_WANT_MAPPED_V4_ADDR option.
Audit all places that touched v4mapped and either sanely construct
a v4 or v6 address then call addr_to_user, or drop the
unnecessary v4mapped check entirely.
Audit all places that call addr_to_user and verify they are on a sycall
return path.
Add a custom getname that formats the address properly.
Several bugs are addressed:
- SCTP_I_WANT_MAPPED_V4_ADDR=0 often returned garbage for
addresses to user space
- The addr_len returned from recvmsg was not correct when
returning AF_INET on a v6 socket
- flowlabel and scope_id were not zerod when promoting
a v4 to v6
- Some syscalls like bind and connect behaved differently
depending on v4mapped
Tested bind, getpeername, getsockname, connect, and recvmsg for proper
behaviour in v4mapped = 1 and 0 cases.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Tested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 2b7cda9c35 upstream.
Based on SNMP values provided by Roman, Yuchung made the observation
that some crashes in tcp_sacktag_walk() might be caused by MTU probing.
Looking at tcp_mtu_probe(), I found that when a new skb was placed
in front of the write queue, we were not updating tcp highest sack.
If one skb is freed because all its content was copied to the new skb
(for MTU probing), then tp->highest_sack could point to a now freed skb.
Bad things would then happen, including infinite loops.
This patch renames tcp_highest_sack_combine() and uses it
from tcp_mtu_probe() to fix the bug.
Note that I also removed one test against tp->sacked_out,
since we want to replace tp->highest_sack regardless of whatever
condition, since keeping a stale pointer to freed skb is a recipe
for disaster.
Fixes: a47e5a988a ("[TCP]: Convert highest_sack to sk_buff to allow direct access")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Reported-by: Roman Gushchin <guro@fb.com>
Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit bc044e8db7 upstream.
The UDP early demux can leverate the rx dst cache even for
multicast unconnected sockets.
In such scenario the ipv4 source address is validated only on
the first packet in the given flow. After that, when we fetch
the dst entry from the socket rx cache, we stop enforcing
the rp_filter and we even start accepting any kind of martian
addresses.
Disabling the dst cache for unconnected multicast socket will
cause large performace regression, nearly reducing by half the
max ingress tput.
Instead we factor out a route helper to completely validate an
skb source address for multicast packets and we call it from
the UDP early demux for mcast packets landing on unconnected
sockets, after successful fetching the related cached dst entry.
This still gives a measurable, but limited performance
regression:
rp_filter = 0 rp_filter = 1
edmux disabled: 1182 Kpps 1127 Kpps
edmux before: 2238 Kpps 2238 Kpps
edmux after: 2037 Kpps 2019 Kpps
The above figures are on top of current net tree.
Applying the net-next commit 6e617de84e ("net: avoid a full
fib lookup when rp_filter is disabled.") the delta with
rp_filter == 0 will decrease even more.
Fixes: 421b3885bf ("udp: ipv4: Add udp early demux")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 7487449c86 upstream.
Currently no error is emitted, but this infrastructure will
used by the next patch to allow source address validation
for mcast sockets.
Since early demux can do a route lookup and an ipv4 route
lookup can return an error code this is consistent with the
current ipv4 route infrastructure.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16:
- Drop change to net_protocol::early_demux_handler
- Keep using NET_INC_STATS_BH() in ip_rcv_finish()
- Fix up additional return statement in udp_v4_early_demux()
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit fb452a1aa3 upstream.
This reverts commit 6d7b857d54.
There is a bug in fragmentation codes use of the percpu_counter API,
that can cause issues on systems with many CPUs.
The frag_mem_limit() just reads the global counter (fbc->count),
without considering other CPUs can have upto batch size (130K) that
haven't been subtracted yet. Due to the 3MBytes lower thresh limit,
this become dangerous at >=24 CPUs (3*1024*1024/130000=24).
The correct API usage would be to use __percpu_counter_compare() which
does the right thing, and takes into account the number of (online)
CPUs and batch size, to account for this and call __percpu_counter_sum()
when needed.
We choose to revert the use of the lib/percpu_counter API for frag
memory accounting for several reasons:
1) On systems with CPUs > 24, the heavier fully locked
__percpu_counter_sum() is always invoked, which will be more
expensive than the atomic_t that is reverted to.
Given systems with more than 24 CPUs are becoming common this doesn't
seem like a good option. To mitigate this, the batch size could be
decreased and thresh be increased.
2) The add_frag_mem_limit+sub_frag_mem_limit pairs happen on the RX
CPU, before SKBs are pushed into sockets on remote CPUs. Given
NICs can only hash on L2 part of the IP-header, the NIC-RXq's will
likely be limited. Thus, a fair chance that atomic add+dec happen
on the same CPU.
Revert note that commit 1d6119baf0 ("net: fix percpu memory leaks")
removed init_frag_mem_limit() and instead use inet_frags_init_net().
After this revert, inet_frags_uninit_net() becomes empty.
Fixes: 6d7b857d54 ("net: use lib/percpu_counter API for fragmentation mem accounting")
Fixes: 1d6119baf0 ("net: fix percpu memory leaks")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 4e587ea71b upstream.
Commit c5cff8561d adds rcu grace period before freeing fib6_node. This
generates a new sparse warning on rt->rt6i_node related code:
net/ipv6/route.c:1394:30: error: incompatible types in comparison
expression (different address spaces)
./include/net/ip6_fib.h:187:14: error: incompatible types in comparison
expression (different address spaces)
This commit adds "__rcu" tag for rt6i_node and makes sure corresponding
rcu API is used for it.
After this fix, sparse no longer generates the above warning.
Fixes: c5cff8561d ("ipv6: add rcu grace period before freeing fib6_node")
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: drop changes in rt6_cache_allowed_for_pmtu()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit c5cff8561d upstream.
We currently keep rt->rt6i_node pointing to the fib6_node for the route.
And some functions make use of this pointer to dereference the fib6_node
from rt structure, e.g. rt6_check(). However, as there is neither
refcount nor rcu taken when dereferencing rt->rt6i_node, it could
potentially cause crashes as rt->rt6i_node could be set to NULL by other
CPUs when doing a route deletion.
This patch introduces an rcu grace period before freeing fib6_node and
makes sure the functions that dereference it takes rcu_read_lock().
Note: there is no "Fixes" tag because this bug was there in a very
early stage.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit b197df4f0f upstream.
Instead of doing the rt6->rt6i_node check whenever we need
to get the route's cookie. Refactor it into rt6_get_cookie().
It is a prep work to handle FLOWI_FLAG_KNOWN_NH and also
percpu rt6_info later.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 68a66d149a upstream.
This important to call qdisc_tree_reduce_backlog() after changing queue
length. Parent qdisc should deactivate class in ->qlen_notify() called from
qdisc_tree_reduce_backlog() but this happens only if qdisc->q.qlen in zero.
Missed class deactivations leads to crashes/warnings at picking packets
from empty qdisc and corrupting state at reactivating this class in future.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Fixes: 86a7996cc8 ("net_sched: introduce qdisc_replace() helper")
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 3fb07daff8 upstream.
Andrey Konovalov reported crashes in ipv4_mtu()
I could reproduce the issue with KASAN kernels, between
10.246.7.151 and 10.246.7.152 :
1) 20 concurrent netperf -t TCP_RR -H 10.246.7.152 -l 1000 &
2) At the same time run following loop :
while :
do
ip ro add 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500
ip ro del 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500
done
Cong Wang attempted to add back rt->fi in commit
82486aa6f1 ("ipv4: restore rt->fi for reference counting")
but this proved to add some issues that were complex to solve.
Instead, I suggested to add a refcount to the metrics themselves,
being a standalone object (in particular, no reference to other objects)
I tried to make this patch as small as possible to ease its backport,
instead of being super clean. Note that we believe that only ipv4 dst
need to take care of the metric refcount. But if this is wrong,
this patch adds the basic infrastructure to extend this to other
families.
Many thanks to Julian Anastasov for reviewing this patch, and Cong Wang
for his efforts on this problem.
Fixes: 2860583fe8 ("ipv4: Kill rt->fi")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16:
- Give DST_METRICS_REFCOUNTED a value of 4 and struct dst_metrics an
alignment of 8
- Update dst_metrics cache size
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
For the backport of "ipv4: add reference counting to metrics", we will
need a third flag on metrics pointers. This was not needed upstream
as the DST_METRICS_FORCE_OVERWRITE flag has been eliminated there.
In order to use three flag bits we need to increase the alignment of
metrics from 4 to 8 bytes.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 6b84202c94 upstream.
Commit b1f5bfc27a ("sctp: don't dereference ptr before leaving
_sctp_walk_{params, errors}()") tried to fix the issue that it
may overstep the chunk end for _sctp_walk_{params, errors} with
'chunk_end > offset(length) + sizeof(length)'.
But it introduced a side effect: When processing INIT, it verifies
the chunks with 'param.v == chunk_end' after iterating all params
by sctp_walk_params(). With the check 'chunk_end > offset(length)
+ sizeof(length)', it would return when the last param is not yet
accessed. Because the last param usually is fwdtsn supported param
whose size is 4 and 'chunk_end == offset(length) + sizeof(length)'
This is a badly issue even causing sctp couldn't process 4-shakes.
Client would always get abort when connecting to server, due to
the failure of INIT chunk verification on server.
The patch is to use 'chunk_end <= offset(length) + sizeof(length)'
instead of 'chunk_end < offset(length) + sizeof(length)' for both
_sctp_walk_params and _sctp_walk_errors.
Fixes: b1f5bfc27a ("sctp: don't dereference ptr before leaving _sctp_walk_{params, errors}()")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 242d3a49a2 upstream.
For each netns (except init_net), we initialize its null entry
in 3 places:
1) The template itself, as we use kmemdup()
2) Code around dst_init_metrics() in ip6_route_net_init()
3) ip6_route_dev_notify(), which is supposed to initialize it after
loopback registers
Unfortunately the last one still happens in a wrong order because
we expect to initialize net->ipv6.ip6_null_entry->rt6i_idev to
net->loopback_dev's idev, thus we have to do that after we add
idev to loopback. However, this notifier has priority == 0 same as
ipv6_dev_notf, and ipv6_dev_notf is registered after
ip6_route_dev_notifier so it is called actually after
ip6_route_dev_notifier. This is similar to commit 2f460933f5
("ipv6: initialize route null entry in addrconf_init()") which
fixes init_net.
Fix it by picking a smaller priority for ip6_route_dev_notifier.
Also, we have to release the refcnt accordingly when unregistering
loopback_dev because device exit functions are called before subsys
exit functions.
Acked-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 2f460933f5 upstream.
Andrey reported a crash on init_net.ipv6.ip6_null_entry->rt6i_idev
since it is always NULL.
This is clearly wrong, we have code to initialize it to loopback_dev,
unfortunately the order is still not correct.
loopback_dev is registered very early during boot, we lose a chance
to re-initialize it in notifier. addrconf_init() is called after
ip6_route_init(), which means we have no chance to correct it.
Fix it by moving this initialization explicitly after
ipv6_add_dev(init_net.loopback_dev) in addrconf_init().
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 77d4b1d369 upstream.
Alexander reported various KASAN messages triggered in recent kernels
The problem is that ping sockets should not use udp_poll() in the first
place, and recent changes in UDP stack finally exposed this old bug.
Fixes: c319b4d76b ("net: ipv4: add IPPROTO_ICMP socket kind")
Fixes: 6d0bfe2261 ("net: ipv6: Add IPv6 support to the ping socket.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Solar Designer <solar@openwall.com>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Acked-By: Lorenzo Colitti <lorenzo@google.com>
Tested-By: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 9b3eb54106 upstream.
When CONFIG_XFRM_SUB_POLICY=y, xfrm_dst stores a copy of the flowi for
that dst. Unfortunately, the code that allocates and fills this copy
doesn't care about what type of flowi (flowi, flowi4, flowi6) gets
passed. In multiple code paths (from raw_sendmsg, from TCP when
replying to a FIN, in vxlan, geneve, and gre), the flowi that gets
passed to xfrm is actually an on-stack flowi4, so we end up reading
stuff from the stack past the end of the flowi4 struct.
Since xfrm_dst->origin isn't used anywhere following commit
ca116922af ("xfrm: Eliminate "fl" and "pol" args to
xfrm_bundle_ok()."), just get rid of it. xfrm_dst->partner isn't used
either, so get rid of that too.
Fixes: 9d6ec93801 ("ipv4: Use flowi4 in public route lookup interfaces.")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[ Upstream commit 20c64d5cd5 ]
A malicious TCP receiver, sending SACK, can force the sender to split
skbs in write queue and increase its memory usage.
Then, when socket is closed and its write queue purged, we might
overflow sk_forward_alloc (It becomes negative)
sk_mem_reclaim() does nothing in this case, and more than 2GB
are leaked from TCP perspective (tcp_memory_allocated is not changed)
Then warnings trigger from inet_sock_destruct() and
sk_stream_kill_queues() seeing a not zero sk_forward_alloc
All TCP stack can be stuck because TCP is under memory pressure.
A simple fix is to preemptively reclaim from sk_mem_uncharge().
This makes sure a socket wont have more than 2 MB forward allocated,
after burst and idle period.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 1a24e04e4b upstream.
sk_mem_reclaim_partial() goal is to ensure each socket has
one SK_MEM_QUANTUM forward allocation. This is needed both for
performance and better handling of memory pressure situations in
follow up patches.
SK_MEM_QUANTUM is currently a page, but might be reduced to 4096 bytes
as some arches have 64KB pages.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Extracted from commit 62bccb8cdb ("net-timestamp: Make the clone operation
stand-alone from phy timestamping").
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit d71b789688 upstream.
syzkaller found another out of bound access in ip_options_compile(),
or more exactly in cipso_v4_validate()
Fixes: 20e2a86485 ("cipso: handle CIPSO options correctly when NetLabel is disabled")
Fixes: 446fda4f26 ("[NetLabel]: CIPSOv4 engine")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Paul Moore <paul@paul-moore.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 5ce6b04ce9 upstream.
First, log prefix will be truncated to NF_LOG_PREFIXLEN-1, i.e. 127,
at nf_log_packet(), so the extra part is useless.
Second, after adding a log rule with a very very long prefix, we will
fail to dump the nft rules after this _special_ one, but acctually,
they do exist. For example:
# name_65000=$(printf "%0.sQ" {1..65000})
# nft add rule filter output log prefix "$name_65000"
# nft add rule filter output counter
# nft add rule filter output counter
# nft list chain filter output
table ip filter {
chain output {
type filter hook output priority 0; policy accept;
}
}
So now, restrict the log prefix length to NF_LOG_PREFIXLEN-1.
Fixes: 96518518cc ("netfilter: add nftables")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[bwh: Backported to 3.16: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit e6f462df9a upstream.
When mac80211 abandons an association attempt, it may free
all the data structures, but inform cfg80211 and userspace
about it only by sending the deauth frame it received, in
which case cfg80211 has no link to the BSS struct that was
used and will not cfg80211_unhold_bss() it.
Fix this by providing a way to inform cfg80211 of this with
the BSS entry passed, so that it can clean up properly, and
use this ability in the appropriate places in mac80211.
This isn't ideal: some code is more or less duplicated and
tracing is missing. However, it's a fairly small change and
it's thus easier to backport - cleanups can come later.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
[bwh: Backported to 3.16:
- Drop changes to ieee80211_rx_mgmt_deauth(), ieee80211_mgd_deauth()
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit ac6e780070 upstream.
With syzkaller help, Marco Grassi found a bug in TCP stack,
crashing in tcp_collapse()
Root cause is that sk_filter() can truncate the incoming skb,
but TCP stack was not really expecting this to happen.
It probably was expecting a simple DROP or ACCEPT behavior.
We first need to make sure no part of TCP header could be removed.
Then we need to adjust TCP_SKB_CB(skb)->end_seq
Many thanks to syzkaller team and Marco for giving us a reproducer.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Marco Grassi <marco.gra@gmail.com>
Reported-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 4f0c40d944 upstream.
Dccp verifies packet integrity, including length, at initial rcv in
dccp_invalid_packet, later pulls headers in dccp_enqueue_skb.
A call to sk_filter in-between can cause __skb_pull to wrap skb->len.
skb_copy_datagram_msg interprets this as a negative value, so
(correctly) fails with EFAULT. The negative length is reported in
ioctl SIOCINQ or possibly in a DCCP_WARN in dccp_close.
Introduce an sk_receive_skb variant that caps how small a filter
program can trim packets, and call this in dccp with the header
length. Excessively trimmed packets are now processed normally and
queued for reception as 0B payloads.
Fixes: 7c657876b6 ("[DCCP]: Initial implementation")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 23f4ffedb7 upstream.
skb->cb may contain data from previous layers. In the observed scenario,
the garbage data were misinterpreted as IP6CB(skb)->frag_max_size, so
that small packets sent through the tunnel are mistakenly fragmented.
This patch unconditionally clears the control buffer in ip6tunnel_xmit(),
which affects ip6_tunnel, ip6_udp_tunnel and ip6_gre. Currently none of
these tunnels set IP6CB(skb)->flags, otherwise it needs to be done earlier.
Signed-off-by: Eli Cooper <elicooper@gmx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
