Re: [f2fs-dev] [PATCH 4/5 v2] f2fs: sanity check for total valid blocks

[Chao Yu]

On 2018/4/26 23:29, Jaegeuk Kim wrote:
> This patch enhances sanity check for SIT entries.
> 
> 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+bf9253040425feb155ad@xxxxxxxxxxxxxxxxxxxxxxxxx
> 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
> RIP: update_sit_entry+0x1215/0x1590 fs/f2fs/segment.c:1882 RSP: ffff8801af526708
> ---[ end trace f498328bb02610a2 ]---
> 
> Reported-and-tested-by: syzbot+bf9253040425feb155ad@xxxxxxxxxxxxxxxxxxxxxxxxx
> Reported-and-tested-by: syzbot+7d6d31d3bc702f566ce3@xxxxxxxxxxxxxxxxxxxxxxxxx
> Reported-and-tested-by: syzbot+0a725420475916460f12@xxxxxxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>

Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx>

Thanks,