kernel BUG at fs/direct-io.c:LINE!

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 8fe42840 Merge 4.9.141 into android-4.9
git tree: android-4.9
console output: https://syzkaller.appspot.com/x/log.txt?x=16d3703b600000
kernel config: https://syzkaller.appspot.com/x/.config?x=22a5ba9f73b6da1d
dashboard link: https://syzkaller.appspot.com/bug?extid=78ef63333b2ca9b66fa7
compiler: gcc (GCC) 8.0.1 20180413 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+78ef63...@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at fs/direct-io.c:679!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 14829 Comm: syz-executor.0 Not tainted 4.9.141+ #1
task: ffff8801c805df00 task.stack: ffff880191f80000
RIP: 0010:[<ffffffff815d2c73>] [<ffffffff815d2c73>] dio_new_bio
fs/direct-io.c:679 [inline]
RIP: 0010:[<ffffffff815d2c73>] [<ffffffff815d2c73>] dio_send_cur_page
fs/direct-io.c:762 [inline]
RIP: 0010:[<ffffffff815d2c73>] [<ffffffff815d2c73>] do_blockdev_direct_IO
fs/direct-io.c:1294 [inline]
RIP: 0010:[<ffffffff815d2c73>] [<ffffffff815d2c73>]
__blockdev_direct_IO+0x4fe3/0xbd10 fs/direct-io.c:1360
RSP: 0018:ffff880191f87340 EFLAGS: 00010212
RAX: 0000000000040000 RBX: dffffc0000000000 RCX: ffffc9000091f000
RDX: 0000000000001fa5 RSI: ffffffff815d2c73 RDI: ffff8801a80eba8c
RBP: ffff880191f87660 R08: ffff8801c805e848 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000001 R12: ffff8801c8ad0900
R13: 0000000000000000 R14: 00000000001b8018 R15: ffff8801a80eba80
FS: 00007fe880286700(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020b90000 CR3: 00000001d3dd4000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Stack:
0000000000000000 fffffbfff0604a02 ffff880191f87450 ffff8801a80ebb18
ffff880003557000 0000000000001000 000000000000000c ffff8801a80ebaf9
ffff880191f87550 ffffffff00000000 ffff880191f874b0 0000000000000fff
Call Trace:
[<ffffffff816de318>] ext4_direct_IO_write fs/ext4/inode.c:3507 [inline]
[<ffffffff816de318>] ext4_direct_IO+0x978/0x29c0 fs/ext4/inode.c:3663
[<ffffffff81411f64>] generic_file_direct_write+0x284/0x510
mm/filemap.c:2655
[<ffffffff8141240f>] __generic_file_write_iter+0x21f/0x540
mm/filemap.c:2835
[<ffffffff816b328d>] ext4_file_write_iter+0x63d/0xd70 fs/ext4/file.c:165
[<ffffffff815071c7>] vfs_iter_write+0x2d7/0x450 fs/read_write.c:390
[<ffffffff815ae4fb>] iter_file_splice_write+0x5fb/0xb30 fs/splice.c:768
[<ffffffff815b066d>] do_splice_from fs/splice.c:870 [inline]
[<ffffffff815b066d>] do_splice fs/splice.c:1166 [inline]
[<ffffffff815b066d>] SYSC_splice fs/splice.c:1416 [inline]
[<ffffffff815b066d>] SyS_splice+0xe4d/0x14d0 fs/splice.c:1399
[<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
[<ffffffff82817893>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 48 c7 c6 40 8c ab 82 4c 89 ef e8 29 c1 eb ff 0f 0b e8 02 8e d4 ff c7
84 24 24 02 00 00 02 00 00 00 e9 f3 b9 ff ff e8 ed 8d d4 ff <0f> 0b e8 e6
8d d4 ff 8b 84 24 30 02 00 00 85 c0 0f 84 82 01 00
RIP [<ffffffff815d2c73>] dio_new_bio fs/direct-io.c:679 [inline]
RIP [<ffffffff815d2c73>] dio_send_cur_page fs/direct-io.c:762 [inline]
RIP [<ffffffff815d2c73>] do_blockdev_direct_IO fs/direct-io.c:1294 [inline]
RIP [<ffffffff815d2c73>] __blockdev_direct_IO+0x4fe3/0xbd10
fs/direct-io.c:1360
RSP <ffff880191f87340>
ip6_tunnel: ip6tnl1 xmit: Local address not yet configured!
---[ end trace 594ab400559064a4 ]---


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.