From: Eric Dumazet <eric.duma...@gmail.com> Date: Fri, 25 Aug 2017 06:27:05 -0700
> From: Eric Dumazet <eduma...@google.com> > > syszkaller got a hang in tcp stack, related to a bug in > tcp_sendpage_locked() > > root@syzkaller:~# cat /proc/3059/stack > [<ffffffff83de926c>] __lock_sock+0x1dc/0x2f0 > [<ffffffff83de9473>] lock_sock_nested+0xf3/0x110 > [<ffffffff8408ce01>] tcp_sendmsg+0x21/0x50 > [<ffffffff84163b6f>] inet_sendmsg+0x11f/0x5e0 > [<ffffffff83dd8eea>] sock_sendmsg+0xca/0x110 > [<ffffffff83dd9547>] kernel_sendmsg+0x47/0x60 > [<ffffffff83de35dc>] sock_no_sendpage+0x1cc/0x280 > [<ffffffff8408916b>] tcp_sendpage_locked+0x10b/0x160 > [<ffffffff84089203>] tcp_sendpage+0x43/0x60 > [<ffffffff841641da>] inet_sendpage+0x1aa/0x660 > [<ffffffff83dd4fcd>] kernel_sendpage+0x8d/0xe0 > [<ffffffff83dd50ac>] sock_sendpage+0x8c/0xc0 > [<ffffffff81b63300>] pipe_to_sendpage+0x290/0x3b0 > [<ffffffff81b67243>] __splice_from_pipe+0x343/0x750 > [<ffffffff81b6a459>] splice_from_pipe+0x1e9/0x330 > [<ffffffff81b6a5e0>] generic_splice_sendpage+0x40/0x50 > [<ffffffff81b6b1d7>] SyS_splice+0x7b7/0x1610 > [<ffffffff84d77a01>] entry_SYSCALL_64_fastpath+0x1f/0xbe > > Fixes: 306b13eb3cf9 ("proto_ops: Add locked held versions of sendmsg and > sendpage") > Signed-off-by: Eric Dumazet <eduma...@google.com> > Reported-by: Dmitry Vyukov <dvyu...@google.com> APplied, thanks Eric.