syzbot

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN NOPTI
Modules linked in:
CPU: 0 PID: 10885 Comm: syz-executor.3 Not tainted 4.14.145+ #0
task: 000000009189b375 task.stack: 000000006b01b0a8
RIP: 0010:do_tcp_sendpages+0x33c/0x1780 net/ipv4/tcp.c:967
RSP: 0018:ffff8881d28876a8 EFLAGS: 00010206
RAX: 000000000000000f RBX: 0000000000000000 RCX: 0000000000002073
RDX: ffffffff8252cfaa RSI: ffffc90003d5d000 RDI: 0000000000000078
RBP: 0000000000005580 R08: 0000000000028000 R09: ffffed1039ab02e8
R10: ffffed1039ab02e7 R11: ffff8881cd58173f R12: ffffea0006c181c0
R13: dffffc0000000000 R14: ffff8881cd581500 R15: 0000000000028000
FS:  00007f65de768700(0000) GS:ffff8881d7600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200ed000 CR3: 000000019c23c003 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tcp_sendpage_locked net/ipv4/tcp.c:1076 [inline]
 tcp_sendpage_locked+0x81/0x130 net/ipv4/tcp.c:1067
 tcp_sendpage+0x3a/0x60 net/ipv4/tcp.c:1086
 inet_sendpage+0x197/0x5d0 net/ipv4/af_inet.c:777
 kernel_sendpage+0x84/0xd0 net/socket.c:3406
 sock_sendpage+0x84/0xa0 net/socket.c:871
 pipe_to_sendpage+0x23d/0x300 fs/splice.c:451
 splice_from_pipe_feed fs/splice.c:502 [inline]
 __splice_from_pipe+0x331/0x740 fs/splice.c:626
 splice_from_pipe+0xd9/0x140 fs/splice.c:661
 do_splice_from fs/splice.c:851 [inline]
 direct_splice_actor+0x118/0x160 fs/splice.c:1018
 splice_direct_to_actor+0x292/0x760 fs/splice.c:973
 do_splice_direct+0x177/0x240 fs/splice.c:1061
 do_sendfile+0x493/0xb20 fs/read_write.c:1445
 SYSC_sendfile64 fs/read_write.c:1506 [inline]
 SyS_sendfile64+0x11f/0x140 fs/read_write.c:1492
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x459a09
RSP: 002b:00007f65de767c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459a09
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0010010000000002 R11: 0000000000000246 R12: 00007f65de7686d4
R13: 00000000004c71d6 R14: 00000000004dc9e0 R15: 00000000ffffffff
Code: 24 08 48 0f 44 d8 e8 c4 46 de fe 48 85 ed 0f 84 7e 03 00 00 e8 b6 46 de fe 48 8d 7b 78 8b ac 24 c8 00 00 00 48 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 74 08 3c 03 0f 8e 15 11 00 00 2b 6b 78 85 
RIP: do_tcp_sendpages+0x33c/0x1780 net/ipv4/tcp.c:967 RSP: ffff8881d28876a8
---[ end trace 9fcd9d194de1a9a6 ]---