linux-stable.git/net, branch v4.4.288 Linux kernel stable tree af_unix: fix races in sk_peer_pid and sk_peer_cred accesses 2021-10-09T11:24:30+00:00 Eric Dumazet edumazet@google.com 2021-09-29T22:57:50+00:00 323f0968a81b082cf02ef15b447cd35e4328385e commit 35306eb23814444bd4021f8a1c3047d3cb0c8b2b upstream. Jann Horn reported that SO_PEERCRED and SO_PEERGROUPS implementations are racy, as af_unix can concurrently change sk_peer_pid and sk_peer_cred. In order to fix this issue, this patch adds a new spinlock that needs to be used whenever these fields are read or written. Jann also pointed out that l2cap_sock_get_peer_pid_cb() is currently reading sk->sk_peer_pid which makes no sense, as this field is only possibly set by AF_UNIX sockets. We will have to clean this in a separate patch. This could be done by reverting b48596d1dc25 "Bluetooth: L2CAP: Add get_peer_pid callback" or implementing what was truly expected. Fixes: 109f6e39fa07 ("af_unix: Allow SO_PEERCRED to work across namespaces.") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Jann Horn <jannh@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Cc: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: David S. Miller <davem@davemloft.net> [backport note: 4.4 and 4.9 don't have SO_PEERGROUPS, only SO_PEERCRED] [backport note: got rid of sk_get_peer_cred(), no users in 4.4/4.9] Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 35306eb23814444bd4021f8a1c3047d3cb0c8b2b upstream.

Jann Horn reported that SO_PEERCRED and SO_PEERGROUPS implementations
are racy, as af_unix can concurrently change sk_peer_pid and sk_peer_cred.

In order to fix this issue, this patch adds a new spinlock that needs
to be used whenever these fields are read or written.

Jann also pointed out that l2cap_sock_get_peer_pid_cb() is currently
reading sk->sk_peer_pid which makes no sense, as this field
is only possibly set by AF_UNIX sockets.
We will have to clean this in a separate patch.
This could be done by reverting b48596d1dc25 "Bluetooth: L2CAP: Add get_peer_pid callback"
or implementing what was truly expected.

Fixes: 109f6e39fa07 ("af_unix: Allow SO_PEERCRED to work across namespaces.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jann Horn <jannh@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
[backport note: 4.4 and 4.9 don't have SO_PEERGROUPS, only SO_PEERCRED]
[backport note: got rid of sk_get_peer_cred(), no users in 4.4/4.9]
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: ipset: Fix oversized kvmalloc() calls 2021-10-06T08:22:25+00:00 Jozsef Kadlecsik kadlec@netfilter.org 2021-09-06T16:26:34+00:00 c55127a19d3cc334978eaddc2d7cdb19e2c2b29f commit 7bbc3d385bd813077acaf0e6fdb2a86a901f5382 upstream. The commit commit 7661809d493b426e979f39ab512e3adf41fbcc69 Author: Linus Torvalds <torvalds@linux-foundation.org> Date: Wed Jul 14 09:45:49 2021 -0700 mm: don't allow oversized kvmalloc() calls limits the max allocatable memory via kvmalloc() to MAX_INT. Apply the same limit in ipset. Reported-by: syzbot+3493b1873fb3ea827986@syzkaller.appspotmail.com Reported-by: syzbot+2b8443c35458a617c904@syzkaller.appspotmail.com Reported-by: syzbot+ee5cb15f4a0e85e0d54e@syzkaller.appspotmail.com Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 7bbc3d385bd813077acaf0e6fdb2a86a901f5382 upstream.

The commit

commit 7661809d493b426e979f39ab512e3adf41fbcc69
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Wed Jul 14 09:45:49 2021 -0700

    mm: don't allow oversized kvmalloc() calls

limits the max allocatable memory via kvmalloc() to MAX_INT. Apply the
same limit in ipset.

Reported-by: syzbot+3493b1873fb3ea827986@syzkaller.appspotmail.com
Reported-by: syzbot+2b8443c35458a617c904@syzkaller.appspotmail.com
Reported-by: syzbot+ee5cb15f4a0e85e0d54e@syzkaller.appspotmail.com
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipvs: check that ip_vs_conn_tab_bits is between 8 and 20 2021-10-06T08:22:24+00:00 Andrea Claudi aclaudi@redhat.com 2021-09-10T16:08:39+00:00 65993d8d15b2b6b241ae05a94ecd6fdd2f7ce799 [ Upstream commit 69e73dbfda14fbfe748d3812da1244cce2928dcb ] ip_vs_conn_tab_bits may be provided by the user through the conn_tab_bits module parameter. If this value is greater than 31, or less than 0, the shift operator used to derive tab_size causes undefined behaviour. Fix this checking ip_vs_conn_tab_bits value to be in the range specified in ipvs Kconfig. If not, simply use default value. Fixes: 6f7edb4881bf ("IPVS: Allow boot time change of hash size") Reported-by: Yi Chen <yiche@redhat.com> Signed-off-by: Andrea Claudi <aclaudi@redhat.com> Acked-by: Julian Anastasov <ja@ssi.bg> Acked-by: Simon Horman <horms@verge.net.au> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 69e73dbfda14fbfe748d3812da1244cce2928dcb ]

ip_vs_conn_tab_bits may be provided by the user through the
conn_tab_bits module parameter. If this value is greater than 31, or
less than 0, the shift operator used to derive tab_size causes undefined
behaviour.

Fix this checking ip_vs_conn_tab_bits value to be in the range specified
in ipvs Kconfig. If not, simply use default value.

Fixes: 6f7edb4881bf ("IPVS: Allow boot time change of hash size")
Reported-by: Yi Chen <yiche@redhat.com>
Signed-off-by: Andrea Claudi <aclaudi@redhat.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
mac80211: fix use-after-free in CCMP/GCMP RX 2021-10-06T08:22:24+00:00 Johannes Berg johannes.berg@intel.com 2021-09-27T09:58:39+00:00 447d001b875d0e7f211c4ba004916028da994258 commit 94513069eb549737bcfc3d988d6ed4da948a2de8 upstream. When PN checking is done in mac80211, for fragmentation we need to copy the PN to the RX struct so we can later use it to do a comparison, since commit bf30ca922a0c ("mac80211: check defrag PN against current frame"). Unfortunately, in that commit I used the 'hdr' variable without it being necessarily valid, so use-after-free could occur if it was necessary to reallocate (parts of) the frame. Fix this by reloading the variable after the code that results in the reallocations, if any. This fixes https://bugzilla.kernel.org/show_bug.cgi?id=214401. Cc: stable@vger.kernel.org Fixes: bf30ca922a0c ("mac80211: check defrag PN against current frame") Link: https://lore.kernel.org/r/20210927115838.12b9ac6bb233.I1d066acd5408a662c3b6e828122cd314fcb28cdb@changeid Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 94513069eb549737bcfc3d988d6ed4da948a2de8 upstream.

When PN checking is done in mac80211, for fragmentation we need
to copy the PN to the RX struct so we can later use it to do a
comparison, since commit bf30ca922a0c ("mac80211: check defrag
PN against current frame").

Unfortunately, in that commit I used the 'hdr' variable without
it being necessarily valid, so use-after-free could occur if it
was necessary to reallocate (parts of) the frame.

Fix this by reloading the variable after the code that results
in the reallocations, if any.

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=214401.

Cc: stable@vger.kernel.org
Fixes: bf30ca922a0c ("mac80211: check defrag PN against current frame")
Link: https://lore.kernel.org/r/20210927115838.12b9ac6bb233.I1d066acd5408a662c3b6e828122cd314fcb28cdb@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sctp: validate from_addr_param return 2021-09-26T11:33:47+00:00 Marcelo Ricardo Leitner marcelo.leitner@gmail.com 2021-06-28T19:13:41+00:00 c299c5925ab774b64ca6aba87fb8c497f5663780 commit 0c5dc070ff3d6246d22ddd931f23a6266249e3db upstream. Ilja reported that, simply putting it, nothing was validating that from_addr_param functions were operating on initialized memory. That is, the parameter itself was being validated by sctp_walk_params, but it doesn't check for types and their specific sizes and it could be a 0-length one, causing from_addr_param to potentially work over the next parameter or even uninitialized memory. The fix here is to, in all calls to from_addr_param, check if enough space is there for the wanted IP address type. Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 0c5dc070ff3d6246d22ddd931f23a6266249e3db upstream.

Ilja reported that, simply putting it, nothing was validating that
from_addr_param functions were operating on initialized memory. That is,
the parameter itself was being validated by sctp_walk_params, but it
doesn't check for types and their specific sizes and it could be a 0-length
one, causing from_addr_param to potentially work over the next parameter or
even uninitialized memory.

The fix here is to, in all calls to from_addr_param, check if enough space
is there for the wanted IP address type.

Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
9p/trans_virtio: Remove sysfs file on probe failure 2021-09-26T11:33:46+00:00 Xie Yongji xieyongji@bytedance.com 2021-05-17T08:35:57+00:00 1c770e24a7cdeb264884e96eab666970e63b09b1 commit f997ea3b7afc108eb9761f321b57de2d089c7c48 upstream. This ensures we don't leak the sysfs file if we failed to allocate chan->vc_wq during probe. Link: http://lkml.kernel.org/r/20210517083557.172-1-xieyongji@bytedance.com Fixes: 86c8437383ac ("net/9p: Add sysfs mount_tag file for virtio 9P device") Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f997ea3b7afc108eb9761f321b57de2d089c7c48 upstream.

This ensures we don't leak the sysfs file if we failed to
allocate chan->vc_wq during probe.

Link: http://lkml.kernel.org/r/20210517083557.172-1-xieyongji@bytedance.com
Fixes: 86c8437383ac ("net/9p: Add sysfs mount_tag file for virtio 9P device")
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sctp: add param size validation for SCTP_PARAM_SET_PRIMARY 2021-09-26T11:33:46+00:00 Marcelo Ricardo Leitner marcelo.leitner@gmail.com 2021-06-28T19:13:44+00:00 27431d3549dd567bc1ad5ccc969f7a9d0742bfac commit ef6c8d6ccf0c1dccdda092ebe8782777cd7803c9 upstream. When SCTP handles an INIT chunk, it calls for example: sctp_sf_do_5_1B_init sctp_verify_init sctp_verify_param sctp_process_init sctp_process_param handling of SCTP_PARAM_SET_PRIMARY sctp_verify_init() wasn't doing proper size validation and neither the later handling, allowing it to work over the chunk itself, possibly being uninitialized memory. Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ef6c8d6ccf0c1dccdda092ebe8782777cd7803c9 upstream.

When SCTP handles an INIT chunk, it calls for example:
sctp_sf_do_5_1B_init
  sctp_verify_init
    sctp_verify_param
  sctp_process_init
    sctp_process_param
      handling of SCTP_PARAM_SET_PRIMARY

sctp_verify_init() wasn't doing proper size validation and neither the
later handling, allowing it to work over the chunk itself, possibly being
uninitialized memory.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sctp: validate chunk size in __rcv_asconf_lookup 2021-09-26T11:33:46+00:00 Marcelo Ricardo Leitner marcelo.leitner@gmail.com 2021-06-28T19:13:43+00:00 061694089d817da3e82d938d70a876090f1bfac2 commit b6ffe7671b24689c09faa5675dd58f93758a97ae upstream. In one of the fallbacks that SCTP has for identifying an association for an incoming packet, it looks for AddIp chunk (from ASCONF) and take a peek. Thing is, at this stage nothing was validating that the chunk actually had enough content for that, allowing the peek to happen over uninitialized memory. Similar check already exists in actual asconf handling in sctp_verify_asconf(). Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b6ffe7671b24689c09faa5675dd58f93758a97ae upstream.

In one of the fallbacks that SCTP has for identifying an association for an
incoming packet, it looks for AddIp chunk (from ASCONF) and take a peek.
Thing is, at this stage nothing was validating that the chunk actually had
enough content for that, allowing the peek to happen over uninitialized
memory.

Similar check already exists in actual asconf handling in
sctp_verify_asconf().

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/af_unix: fix a data-race in unix_dgram_poll 2021-09-22T09:41:27+00:00 Eric Dumazet edumazet@google.com 2021-09-09T00:00:29+00:00 01cc2a1638c7abe19caf5d9f603025e1f9e80e4d commit 04f08eb44b5011493d77b602fdec29ff0f5c6cd5 upstream. syzbot reported another data-race in af_unix [1] Lets change __skb_insert() to use WRITE_ONCE() when changing skb head qlen. Also, change unix_dgram_poll() to use lockless version of unix_recvq_full() It is verry possible we can switch all/most unix_recvq_full() to the lockless version, this will be done in a future kernel version. [1] HEAD commit: 8596e589b787732c8346f0482919e83cc9362db1 BUG: KCSAN: data-race in skb_queue_tail / unix_dgram_poll write to 0xffff88814eeb24e0 of 4 bytes by task 25815 on cpu 0: __skb_insert include/linux/skbuff.h:1938 [inline] __skb_queue_before include/linux/skbuff.h:2043 [inline] __skb_queue_tail include/linux/skbuff.h:2076 [inline] skb_queue_tail+0x80/0xa0 net/core/skbuff.c:3264 unix_dgram_sendmsg+0xff2/0x1600 net/unix/af_unix.c:1850 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg net/socket.c:723 [inline] ____sys_sendmsg+0x360/0x4d0 net/socket.c:2392 ___sys_sendmsg net/socket.c:2446 [inline] __sys_sendmmsg+0x315/0x4b0 net/socket.c:2532 __do_sys_sendmmsg net/socket.c:2561 [inline] __se_sys_sendmmsg net/socket.c:2558 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2558 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88814eeb24e0 of 4 bytes by task 25834 on cpu 1: skb_queue_len include/linux/skbuff.h:1869 [inline] unix_recvq_full net/unix/af_unix.c:194 [inline] unix_dgram_poll+0x2bc/0x3e0 net/unix/af_unix.c:2777 sock_poll+0x23e/0x260 net/socket.c:1288 vfs_poll include/linux/poll.h:90 [inline] ep_item_poll fs/eventpoll.c:846 [inline] ep_send_events fs/eventpoll.c:1683 [inline] ep_poll fs/eventpoll.c:1798 [inline] do_epoll_wait+0x6ad/0xf00 fs/eventpoll.c:2226 __do_sys_epoll_wait fs/eventpoll.c:2238 [inline] __se_sys_epoll_wait fs/eventpoll.c:2233 [inline] __x64_sys_epoll_wait+0xf6/0x120 fs/eventpoll.c:2233 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x0000001b -> 0x00000001 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 25834 Comm: syz-executor.1 Tainted: G W 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 86b18aaa2b5b ("skbuff: fix a data race in skb_queue_len()") Cc: Qian Cai <cai@lca.pw> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 04f08eb44b5011493d77b602fdec29ff0f5c6cd5 upstream.

syzbot reported another data-race in af_unix [1]

Lets change __skb_insert() to use WRITE_ONCE() when changing
skb head qlen.

Also, change unix_dgram_poll() to use lockless version
of unix_recvq_full()

It is verry possible we can switch all/most unix_recvq_full()
to the lockless version, this will be done in a future kernel version.

[1] HEAD commit: 8596e589b787732c8346f0482919e83cc9362db1

BUG: KCSAN: data-race in skb_queue_tail / unix_dgram_poll

write to 0xffff88814eeb24e0 of 4 bytes by task 25815 on cpu 0:
 __skb_insert include/linux/skbuff.h:1938 [inline]
 __skb_queue_before include/linux/skbuff.h:2043 [inline]
 __skb_queue_tail include/linux/skbuff.h:2076 [inline]
 skb_queue_tail+0x80/0xa0 net/core/skbuff.c:3264
 unix_dgram_sendmsg+0xff2/0x1600 net/unix/af_unix.c:1850
 sock_sendmsg_nosec net/socket.c:703 [inline]
 sock_sendmsg net/socket.c:723 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2392
 ___sys_sendmsg net/socket.c:2446 [inline]
 __sys_sendmmsg+0x315/0x4b0 net/socket.c:2532
 __do_sys_sendmmsg net/socket.c:2561 [inline]
 __se_sys_sendmmsg net/socket.c:2558 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2558
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88814eeb24e0 of 4 bytes by task 25834 on cpu 1:
 skb_queue_len include/linux/skbuff.h:1869 [inline]
 unix_recvq_full net/unix/af_unix.c:194 [inline]
 unix_dgram_poll+0x2bc/0x3e0 net/unix/af_unix.c:2777
 sock_poll+0x23e/0x260 net/socket.c:1288
 vfs_poll include/linux/poll.h:90 [inline]
 ep_item_poll fs/eventpoll.c:846 [inline]
 ep_send_events fs/eventpoll.c:1683 [inline]
 ep_poll fs/eventpoll.c:1798 [inline]
 do_epoll_wait+0x6ad/0xf00 fs/eventpoll.c:2226
 __do_sys_epoll_wait fs/eventpoll.c:2238 [inline]
 __se_sys_epoll_wait fs/eventpoll.c:2233 [inline]
 __x64_sys_epoll_wait+0xf6/0x120 fs/eventpoll.c:2233
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000001b -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 25834 Comm: syz-executor.1 Tainted: G        W         5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 86b18aaa2b5b ("skbuff: fix a data race in skb_queue_len()")
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tipc: increase timeout in tipc_sk_enqueue() 2021-09-22T09:41:27+00:00 Hoang Le hoang.h.le@dektech.com.au 2021-09-13T09:28:52+00:00 44f2a9f34770d9dc879ea15994f2f90bc9485dbe commit f4bb62e64c88c93060c051195d3bbba804e56945 upstream. In tipc_sk_enqueue() we use hardcoded 2 jiffies to extract socket buffer from generic queue to particular socket. The 2 jiffies is too short in case there are other high priority tasks get CPU cycles for multiple jiffies update. As result, no buffer could be enqueued to particular socket. To solve this, we switch to use constant timeout 20msecs. Then, the function will be expired between 2 jiffies (CONFIG_100HZ) and 20 jiffies (CONFIG_1000HZ). Fixes: c637c1035534 ("tipc: resolve race problem at unicast message reception") Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f4bb62e64c88c93060c051195d3bbba804e56945 upstream.

In tipc_sk_enqueue() we use hardcoded 2 jiffies to extract
socket buffer from generic queue to particular socket.
The 2 jiffies is too short in case there are other high priority
tasks get CPU cycles for multiple jiffies update. As result, no
buffer could be enqueued to particular socket.

To solve this, we switch to use constant timeout 20msecs.
Then, the function will be expired between 2 jiffies (CONFIG_100HZ)
and 20 jiffies (CONFIG_1000HZ).

Fixes: c637c1035534 ("tipc: resolve race problem at unicast message reception")
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>