kernel BUG at fs/block_dev.c:LINE!

From: syzbot
Date: Tue Oct 09 2018 - 00:24:09 EST


Hello,

syzbot found the following crash on:

HEAD commit: 0854ba5ff5c9 Merge git://git.kernel.org/pub/scm/linux/kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1554ec06400000
kernel config: https://syzkaller.appspot.com/x/.config?x=88e9a8a39dc0be2d
dashboard link: https://syzkaller.appspot.com/bug?extid=82909b30c4657137bf84
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10331976400000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=165db54e400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+82909b30c4657137bf84@xxxxxxxxxxxxxxxxxxxxxxxxx

loop1: p1
loop4: p1
loop3: p1
loop5: p1
------------[ cut here ]------------
kernel BUG at fs/block_dev.c:1627!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 6913 Comm: syz-executor753 Not tainted 4.19.0-rc7+ #53
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:blkdev_get+0x65f/0xb50 fs/block_dev.c:1627
Code: ff ff ff 0f 84 4d 03 00 00 48 89 85 f0 fe ff ff e8 f6 fa 9d ff 48 8b 85 f0 fe ff ff 48 85 c0 0f 84 9b 00 00 00 e8 e1 fa 9d ff <0f> 0b e8 da fa 9d ff 4c 89 e2 48 b8 00 00 00 00 00 fc ff df 48 c1
RSP: 0018:ffff8801c0a8f578 EFLAGS: 00010293
RAX: ffff8801c083a700 RBX: 0000000000000000 RCX: ffffffff81e0da52
RDX: 0000000000000000 RSI: ffffffff81e0daaf RDI: 0000000000000005
RBP: ffff8801c0a8f6a8 R08: ffff8801c083a700 R09: fffffbfff12424f0
R10: fffffbfff12424f0 R11: ffffffff89212783 R12: ffff8801d3ac0318
R13: ffff8801d3bee2d8 R14: ffff8801d3bee2c0 R15: ffff8801d3ac0280
FS: 0000000001359880(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000606ed8 CR3: 00000001c12d3000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
blkdev_open+0x1fb/0x280 fs/block_dev.c:1775
do_dentry_open+0x499/0x1250 fs/open.c:771
vfs_open+0xa0/0xd0 fs/open.c:880
do_last fs/namei.c:3418 [inline]
path_openat+0x12bf/0x5160 fs/namei.c:3534
do_filp_open+0x255/0x380 fs/namei.c:3564
do_sys_open+0x568/0x700 fs/open.c:1063
__do_sys_openat fs/open.c:1090 [inline]
__se_sys_openat fs/open.c:1084 [inline]
__x64_sys_openat+0x9d/0x100 fs/open.c:1084
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x445589
Code: fd cd fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb cd fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd31e04eb8 EFLAGS: 00000286 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000020000080 RCX: 0000000000445589
RDX: 00000000008001a0 RSI: 0000000020000080 RDI: 00000000ffffff9c
RBP: 706e692f7665642f R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000286 R12: 0000000000069554
R13: 0000000000402870 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace bcaf07e3e9ad4219 ]---
RIP: 0010:blkdev_get+0x65f/0xb50 fs/block_dev.c:1627
Code: ff ff ff 0f 84 4d 03 00 00 48 89 85 f0 fe ff ff e8 f6 fa 9d ff 48 8b 85 f0 fe ff ff 48 85 c0 0f 84 9b 00 00 00 e8 e1 fa 9d ff <0f> 0b e8 da fa 9d ff 4c 89 e2 48 b8 00 00 00 00 00 fc ff df 48 c1
RSP: 0018:ffff8801c0a8f578 EFLAGS: 00010293
RAX: ffff8801c083a700 RBX: 0000000000000000 RCX: ffffffff81e0da52
RDX: 0000000000000000 RSI: ffffffff81e0daaf RDI: 0000000000000005
RBP: ffff8801c0a8f6a8 R08: ffff8801c083a700 R09: fffffbfff12424f0
R10: fffffbfff12424f0 R11: ffffffff89212783 R12: ffff8801d3ac0318
R13: ffff8801d3bee2d8 R14: ffff8801d3bee2c0 R15: ffff8801d3ac0280
FS: 0000000001359880(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000606ed8 CR3: 00000001c12d3000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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