f2fs: sanity check on sit entry
syzbot hit the following crash on upstream commit
87ef12027b9b1dd0e0b12cf311fbcb19f9d92539 (Wed Apr 18 19:48:17 2018 +0000)
Merge tag 'ceph-for-4.17-rc2' of git://github.com/ceph/ceph-client
link: https://syzkaller.appspot.com/bug?extid=83699adeb2d13579c31e
C reproducer: https://syzkaller.appspot.com/x/repro.c?id=
5805208181407744
syzkaller reproducer: https://syzkaller.appspot.com/x/repro.syz?id=
6005073343676416
Raw console output: https://syzkaller.appspot.com/x/log.txt?id=
6555047731134464
Kernel config: https://syzkaller.appspot.com/x/.config?id=
1808800213120130118
compiler: gcc (GCC) 8.0.1
20180413 (experimental)
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+83699adeb2d13579c31e@syzkaller.appspotmail.com
It will help syzbot understand when the bug is fixed. See footer for details.
If you forward the report, please keep this part and the footer.
F2FS-fs (loop0): Magic Mismatch, valid(0xf2f52010) - read(0x0)
F2FS-fs (loop0): Can't find valid F2FS filesystem in 1th superblock
F2FS-fs (loop0): invalid crc value
BUG: unable to handle kernel paging request at
ffffed006b2a50c0
PGD
21ffee067 P4D
21ffee067 PUD
21fbeb067 PMD 0
Oops: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 4514 Comm: syzkaller989480 Not tainted 4.17.0-rc1+ #8
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:build_sit_entries fs/f2fs/segment.c:3653 [inline]
RIP: 0010:build_segment_manager+0x7ef7/0xbf70 fs/f2fs/segment.c:3852
RSP: 0018:
ffff8801b102e5b0 EFLAGS:
00010a06
RAX:
1ffff1006b2a50c0 RBX:
0000000000000004 RCX:
0000000000000001
RDX:
0000000000000000 RSI:
0000000000000001 RDI:
ffff8801ac74243e
RBP:
ffff8801b102f410 R08:
ffff8801acbd46c0 R09:
fffffbfff14d9af8
R10:
fffffbfff14d9af8 R11:
ffff8801acbd46c0 R12:
ffff8801ac742a80
R13:
ffff8801d9519100 R14:
dffffc0000000000 R15:
ffff880359528600
FS:
0000000001e04880(0000) GS:
ffff8801dae00000(0000) knlGS:
0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
CR2:
ffffed006b2a50c0 CR3:
00000001ac6ac000 CR4:
00000000001406f0
DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
Call Trace:
f2fs_fill_super+0x4095/0x7bf0 fs/f2fs/super.c:2803
mount_bdev+0x30c/0x3e0 fs/super.c:1165
f2fs_mount+0x34/0x40 fs/f2fs/super.c:3020
mount_fs+0xae/0x328 fs/super.c:1268
vfs_kern_mount.part.34+0xd4/0x4d0 fs/namespace.c:1037
vfs_kern_mount fs/namespace.c:1027 [inline]
do_new_mount fs/namespace.c:2517 [inline]
do_mount+0x564/0x3070 fs/namespace.c:2847
ksys_mount+0x12d/0x140 fs/namespace.c:3063
__do_sys_mount fs/namespace.c:3077 [inline]
__se_sys_mount fs/namespace.c:3074 [inline]
__x64_sys_mount+0xbe/0x150 fs/namespace.c:3074
do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x443d6a
RSP: 002b:
00007ffd312813c8 EFLAGS:
00000297 ORIG_RAX:
00000000000000a5
RAX:
ffffffffffffffda RBX:
0000000020000c00 RCX:
0000000000443d6a
RDX:
0000000020000000 RSI:
0000000020000100 RDI:
00007ffd312813d0
RBP:
0000000000000003 R08:
0000000020016a00 R09:
000000000000000a
R10:
0000000000000000 R11:
0000000000000297 R12:
0000000000000004
R13:
0000000000402c60 R14:
0000000000000000 R15:
0000000000000000
RIP: build_sit_entries fs/f2fs/segment.c:3653 [inline] RSP:
ffff8801b102e5b0
RIP: build_segment_manager+0x7ef7/0xbf70 fs/f2fs/segment.c:3852 RSP:
ffff8801b102e5b0
CR2:
ffffed006b2a50c0
---[ end trace
a2034989e196ff17 ]---
Reported-and-tested-by: syzbot+83699adeb2d13579c31e@syzkaller.appspotmail.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>