------------[ cut here ]------------
WARNING: CPU: 1 PID: 6750 at net/core/skbuff.c:4398 skb_try_coalesce+0xeb7/0x1260 net/core/skbuff.c:4398
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 6750 Comm: syz-executor.5 Not tainted 4.9.205-syzkaller #0
 ffff8800b2b87030 ffffffff81b55e6b 0000000000000000 ffffffff82a3b700
 00000000ffffffff 0000000000000001 0000000000000009 ffff8800b2b87110
 ffffffff813ff051 0000000041b58ab3 ffffffff82e316eb ffffffff813fee71
Call Trace:
 [<00000000fe4019dc>] __dump_stack lib/dump_stack.c:15 [inline]
 [<00000000fe4019dc>] dump_stack+0xcb/0x130 lib/dump_stack.c:56
 [<000000004b162bdd>] panic+0x1e0/0x3c4 kernel/panic.c:181
 [<000000003451cab2>] __warn.cold+0x2f/0x2f kernel/panic.c:547
 [<000000005bb8d175>] warn_slowpath_null+0x2d/0x40 kernel/panic.c:590
 [<000000005b1b988a>] skb_try_coalesce+0xeb7/0x1260 net/core/skbuff.c:4398
 [<000000000addcf87>] tcp_try_coalesce+0x173/0x4e0 net/ipv4/tcp_input.c:4378
 [<000000000f185089>] tcp_queue_rcv+0x129/0x5a0 net/ipv4/tcp_input.c:4630
 [<00000000c46d8bbd>] tcp_data_queue+0x600/0x3810 net/ipv4/tcp_input.c:4739
 [<00000000284492c8>] tcp_rcv_established+0x55a/0x20b0 net/ipv4/tcp_input.c:5620
 [<0000000065f3cbfd>] tcp_v6_do_rcv+0xcd9/0x10f0 net/ipv6/tcp_ipv6.c:1283
 [<00000000eb45fa53>] sk_backlog_rcv include/net/sock.h:881 [inline]
 [<00000000eb45fa53>] __release_sock+0x138/0x390 net/core/sock.c:2065
 [<000000009decbec4>] release_sock+0x59/0x1c0 net/core/sock.c:2529
 [<00000000cbd5608b>] tcp_sendpage net/ipv4/tcp.c:1034 [inline]
 [<00000000cbd5608b>] tcp_sendpage+0x6b4/0x18f0 net/ipv4/tcp.c:1019
 [<00000000d6a813c3>] inet_sendpage+0x223/0x520 net/ipv4/af_inet.c:783
 [<0000000093102211>] kernel_sendpage+0x95/0xf0 net/socket.c:3326
 [<000000000f761651>] sock_sendpage+0x8b/0xc0 net/socket.c:803
 [<00000000314e95e2>] pipe_to_sendpage+0x28d/0x3d0 fs/splice.c:470
 [<000000005dbe7501>] splice_from_pipe_feed fs/splice.c:521 [inline]
 [<000000005dbe7501>] __splice_from_pipe+0x351/0x790 fs/splice.c:645
 [<00000000ab93e17b>] splice_from_pipe+0x108/0x170 fs/splice.c:680
 [<00000000cbb02632>] generic_splice_sendpage+0x3c/0x50 fs/splice.c:851
 [<00000000725bb36e>] do_splice_from fs/splice.c:870 [inline]
 [<00000000725bb36e>] direct_splice_actor+0x126/0x1a0 fs/splice.c:1037
 [<00000000df1d364f>] splice_direct_to_actor+0x2c8/0x820 fs/splice.c:992
 [<000000002ef8a82a>] do_splice_direct+0x1a5/0x260 fs/splice.c:1080
 [<00000000bff57550>] do_sendfile+0x503/0xc00 fs/read_write.c:1402
 [<00000000bbe2282e>] SYSC_sendfile64 fs/read_write.c:1463 [inline]
 [<00000000bbe2282e>] SyS_sendfile64+0x145/0x160 fs/read_write.c:1449
 [<00000000d4b7635f>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288
 [<00000000ff633c5e>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Kernel Offset: disabled
Rebooting in 86400 seconds..