kernel BUG at fs/f2fs/segment.c:LINE!

[syzbot]

Hello,

syzbot hit the following crash on upstream commit
83beed7b2b26f232d782127792dd0cd4362fdc41 (Fri Apr 20 17:56:32 2018 +0000)
Merge branch 'fixes' of
git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal
syzbot dashboard link:
https://syzkaller.appspot.com/bug?extid=bf9253040425feb155ad

syzkaller reproducer:
https://syzkaller.appspot.com/x/repro.syz?id=5692130282438656
Raw console output:
https://syzkaller.appspot.com/x/log.txt?id=5095924598571008
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+bf9253...@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): invalid crc value
F2FS-fs (loop0): Try to recover 1th superblock, ret: 0
F2FS-fs (loop0): Mounted with checkpoint version = d
F2FS-fs (loop0): Bitmap was wrongly cleared, blk:9740
------------[ cut here ]------------
kernel BUG at fs/f2fs/segment.c:1884!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 4508 Comm: syz-executor0 Not tainted 4.17.0-rc1+ #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:update_sit_entry+0x1215/0x1590 fs/f2fs/segment.c:1882
RSP: 0018:ffff8801af526708 EFLAGS: 00010282
RAX: ffffed0035ea4cc0 RBX: ffff8801ad454f90 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff82eeb87e RDI: ffffed0035ea4cb6
RBP: ffff8801af526760 R08: ffff8801ad4a2480 R09: ffffed003b5e4f90
R10: ffffed003b5e4f90 R11: ffff8801daf27c87 R12: ffff8801adb8d380
R13: 0000000000000001 R14: 0000000000000008 R15: 00000000ffffffff
FS: 00000000014af940(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f06bc223000 CR3: 00000001adb02000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
allocate_data_block+0x66f/0x2050 fs/f2fs/segment.c:2663
do_write_page+0x105/0x1b0 fs/f2fs/segment.c:2727
write_node_page+0x129/0x350 fs/f2fs/segment.c:2770
__write_node_page+0x7da/0x1370 fs/f2fs/node.c:1398
sync_node_pages+0x18cf/0x1eb0 fs/f2fs/node.c:1652
block_operations+0x429/0xa60 fs/f2fs/checkpoint.c:1088
write_checkpoint+0x3ba/0x5380 fs/f2fs/checkpoint.c:1405
f2fs_sync_fs+0x2fb/0x6a0 fs/f2fs/super.c:1077
__sync_filesystem fs/sync.c:39 [inline]
sync_filesystem+0x265/0x310 fs/sync.c:67
generic_shutdown_super+0xd7/0x520 fs/super.c:429
kill_block_super+0xa4/0x100 fs/super.c:1191
kill_f2fs_super+0x9f/0xd0 fs/f2fs/super.c:3030
deactivate_locked_super+0x97/0x100 fs/super.c:316
deactivate_super+0x188/0x1b0 fs/super.c:347
cleanup_mnt+0xbf/0x160 fs/namespace.c:1174
__cleanup_mnt+0x16/0x20 fs/namespace.c:1181
task_work_run+0x1e4/0x290 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:191 [inline]
exit_to_usermode_loop+0x2bd/0x310 arch/x86/entry/common.c:166
prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457d97
RSP: 002b:00007ffd46f9c8e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000457d97
RDX: 00000000014b09a3 RSI: 0000000000000002 RDI: 00007ffd46f9da50
RBP: 00007ffd46f9da50 R08: 0000000000000000 R09: 0000000000000009
R10: 0000000000000005 R11: 0000000000000246 R12: 00000000014b0940
R13: 0000000000000000 R14: 0000000000000002 R15: 000000000000658e
Code: c6 40 d6 f2 87 e8 5c 1d f6 ff 0f 0b e8 15 96 80 fe 8b 4d d0 48 8b 7d
b8 48 c7 c2 20 d7 f2 87 48 c7 c6 40 d6 f2 87 e8 3b 1d f6 ff <0f> 0b e8 e4
f0 bc fe e9 73 ef ff ff 4c 89 ef e8 d7 f0 bc fe e9
RIP: update_sit_entry+0x1215/0x1590 fs/f2fs/segment.c:1882 RSP:
ffff8801af526708
---[ end trace f498328bb02610a2 ]---


---
This bug is generated by a dumb bot. It may contain errors.
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[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer still triggered
crash:
kernel BUG at fs/f2fs/segment.c:LINE!

F2FS-fs (loop0): invalid crc value
F2FS-fs (loop0): Try to recover 1th superblock, ret: 0
F2FS-fs (loop0): Mounted with checkpoint version = d
F2FS-fs (loop0): Bitmap was wrongly cleared, blk:9740
------------[ cut here ]------------

kernel BUG at fs/f2fs/segment.c:1899!

invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:

CPU: 0 PID: 4842 Comm: syz-executor Not tainted 4.17.0-rc1+ #1

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011

RIP: 0010:update_sit_entry+0x1215/0x1590 fs/f2fs/segment.c:1897
RSP: 0018:ffff8801b468e708 EFLAGS: 00010282
RAX: ffffed00368d1cc0 RBX: ffff8801c1517d50 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff82eebbae RDI: ffffed00368d1cb6
RBP: ffff8801b468e760 R08: ffff8801d31004c0 R09: ffffed003b5c4f90
R10: ffffed003b5c4f90 R11: ffff8801dae27c87 R12: ffff8801bf1682c0

R13: 0000000000000001 R14: 0000000000000008 R15: 00000000ffffffff

FS: 0000000001154940(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 000000000197cb38 CR3: 00000001b9ec2000 CR4: 00000000001406f0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:

allocate_data_block+0x66f/0x2050 fs/f2fs/segment.c:2666
do_write_page+0x105/0x1b0 fs/f2fs/segment.c:2730
F2FS-fs (loop2): Magic Mismatch, valid(0xf2f52010) - read(0x0)
write_node_page+0x129/0x350 fs/f2fs/segment.c:2774
__write_node_page+0x7f9/0x1340 fs/f2fs/node.c:1418
F2FS-fs (loop2): Can't find valid F2FS filesystem in 1th superblock
F2FS-fs (loop7): Magic Mismatch, valid(0xf2f52010) - read(0x0)
sync_node_pages+0x18cf/0x1eb0 fs/f2fs/node.c:1672
F2FS-fs (loop7): Can't find valid F2FS filesystem in 1th superblock
block_operations+0x429/0xa60 fs/f2fs/checkpoint.c:1091
write_checkpoint+0x3ba/0x5380 fs/f2fs/checkpoint.c:1408

f2fs_sync_fs+0x2fb/0x6a0 fs/f2fs/super.c:1077
__sync_filesystem fs/sync.c:39 [inline]
sync_filesystem+0x265/0x310 fs/sync.c:67

generic_shutdown_super+0xd7/0x520 fs/super.c:426
kill_block_super+0xa4/0x100 fs/super.c:1192
kill_f2fs_super+0x9f/0xd0 fs/f2fs/super.c:3030
deactivate_locked_super+0x97/0x100 fs/super.c:313
deactivate_super+0x188/0x1b0 fs/super.c:344
cleanup_mnt+0xbf/0x160 fs/namespace.c:1173
__cleanup_mnt+0x16/0x20 fs/namespace.c:1180

task_work_run+0x1e4/0x290 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:191 [inline]
exit_to_usermode_loop+0x2bd/0x310 arch/x86/entry/common.c:166
prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457d97

RSP: 002b:00007ffc385209e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6

RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000457d97

RDX: 000000000115599b RSI: 0000000000000002 RDI: 00007ffc38521b50
RBP: 00007ffc38521b50 R08: 0000000000000000 R09: 0000000000000009
R10: 0000000000000005 R11: 0000000000000246 R12: 0000000001155940
R13: 0000000000000000 R14: 0000000000000002 R15: 000000000000fa23
Code: c6 c0 d6 f2 87 e8 cc 1e f6 ff 0f 0b e8 55 94 80 fe 8b 4d d0 48 8b 7d
b8 48 c7 c2 60 d8 f2 87 48 c7 c6 c0 d6 f2 87 e8 ab 1e f6 ff <0f> 0b e8 94
ee bc fe e9 73 ef ff ff 4c 89 ef e8 87 ee bc fe e9
RIP: update_sit_entry+0x1215/0x1590 fs/f2fs/segment.c:1897 RSP:
ffff8801b468e708
---[ end trace e4165a5d7471634a ]---


Tested on https://github.com/jaegeuk/f2fs.git/g-dev-test commit
f123909f411a4a8bcda78f7b5fed802f2b3bc06e (Fri Apr 20 04:10:28 2018 +0000)
Revert "fs/dcache.c: add cond_resched() in shrink_dentry_list()"

compiler: gcc (GCC) 8.0.1 20180413 (experimental)

Kernel config:
https://syzkaller.appspot.com/x/.config?id=1808800213120130118
Raw console output:
https://syzkaller.appspot.com/x/log.txt?id=5474350945796096

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger
crash:

Reported-and-tested-by:
syzbot+bf9253...@syzkaller.appspotmail.com

Note: the tag will also help syzbot to understand when the bug is fixed.

Tested on https://github.com/jaegeuk/f2fs.git/g-dev-test commit

8edc313bb9f450a72a528369045b85f2f834ea17 (Fri Apr 20 04:10:28 2018 +0000)

Revert "fs/dcache.c: add cond_resched() in shrink_dentry_list()"

compiler: gcc (GCC) 8.0.1 20180413 (experimental)
Kernel config:
https://syzkaller.appspot.com/x/.config?id=1808800213120130118

---
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The entire risk as to the quality of the result is with you. Should the
result
prove defective, you assume the cost of all necessary servicing, repair or
correction.

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger
crash:

Reported-and-tested-by:
syzbot+bf9253...@syzkaller.appspotmail.com

Note: the tag will also help syzbot to understand when the bug is fixed.

Tested on https://github.com/jaegeuk/f2fs.git/g-dev-test commit

b3a173a243afb71fc3d222348a7aa4bca5b93249 (Fri Apr 20 04:10:28 2018 +0000)