linux/include
Eric Dumazet 7716682cc5 tcp/dccp: fix another race at listener dismantle
Ilya reported following lockdep splat:

kernel: =========================
kernel: [ BUG: held lock freed! ]
kernel: 4.5.0-rc1-ceph-00026-g5e0a311 #1 Not tainted
kernel: -------------------------
kernel: swapper/5/0 is freeing memory
ffff880035c9d200-ffff880035c9dbff, with a lock still held there!
kernel: (&(&queue->rskq_lock)->rlock){+.-...}, at:
[<ffffffff816f6a88>] inet_csk_reqsk_queue_add+0x28/0xa0
kernel: 4 locks held by swapper/5/0:
kernel: #0:  (rcu_read_lock){......}, at: [<ffffffff8169ef6b>]
netif_receive_skb_internal+0x4b/0x1f0
kernel: #1:  (rcu_read_lock){......}, at: [<ffffffff816e977f>]
ip_local_deliver_finish+0x3f/0x380
kernel: #2:  (slock-AF_INET){+.-...}, at: [<ffffffff81685ffb>]
sk_clone_lock+0x19b/0x440
kernel: #3:  (&(&queue->rskq_lock)->rlock){+.-...}, at:
[<ffffffff816f6a88>] inet_csk_reqsk_queue_add+0x28/0xa0

To properly fix this issue, inet_csk_reqsk_queue_add() needs
to return to its callers if the child as been queued
into accept queue.

We also need to make sure listener is still there before
calling sk->sk_data_ready(), by holding a reference on it,
since the reference carried by the child can disappear as
soon as the child is put on accept queue.

Reported-by: Ilya Dryomov <idryomov@gmail.com>
Fixes: ebb516af60 ("tcp/dccp: fix race at listener dismantle phase")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-18 11:35:51 -05:00
..
acpi ACPI / CPPC: remove redundant mbox_send_message() declaration 2016-02-03 01:09:52 +01:00
asm-generic Merge branch 'akpm' (patches from Andrew) 2016-01-21 12:32:08 -08:00
clocksource
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2016-01-22 11:58:43 -08:00
drm Merge branch 'drm-fixes-mst' of git://people.freedesktop.org/~airlied/linux into drm-fixes 2016-02-05 15:24:17 +10:00
dt-bindings ARM: SoC driver updates for v4.5 2016-01-20 18:42:30 -08:00
keys Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into next 2015-12-26 16:06:53 +11:00
kvm
linux net/mlx4_core: Set UAR page size to 4KB regardless of system page size 2016-02-17 10:29:27 -05:00
math-emu
media [media] vb2: fix nasty vb2_thread regression 2016-02-04 09:13:46 -02:00
memory
misc
net tcp/dccp: fix another race at listener dismantle 2016-02-18 11:35:51 -05:00
pcmcia
ras
rdma IB/mlx4: Enable send of RoCE QP1 packets with IP/UDP headers 2016-01-19 15:35:01 -05:00
rxrpc
scsi Initial roundup of 4.5 merge window patches 2016-01-23 18:45:06 -08:00
soc ARM: SoC driver updates for v4.5 2016-01-20 18:42:30 -08:00
sound ALSA: rawmidi: Make snd_rawmidi_transmit() race-free 2016-02-03 14:51:28 +01:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2016-01-20 17:20:53 -08:00
trace This includes three minor fixes, mostly due to cut-and-paste issues. 2016-01-28 17:00:50 -08:00
uapi Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm 2016-02-01 15:21:20 -08:00
video omapdss: remove CONFIG_OMAP2_DSS_VENC from omapdss.h 2015-12-29 11:07:46 +02:00
xen Merge branch 'for-4.5/drivers' of git://git.kernel.dk/linux-block 2016-01-21 18:19:38 -08:00
Kbuild