[syzbot] [f2fs?] kernel BUG in f2fs_evict_inode (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9d5906799f7d Merge tag 'selinux-pr-20240814' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=152a1a05980000
kernel config: https://syzkaller.appspot.com/x/.config?x=92c0312151c4e32e
dashboard link: https://syzkaller.appspot.com/bug?extid=ebea2790904673d7c618
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/446819619a5c/disk-9d590679.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/14a59529d386/vmlinux-9d590679.xz
kernel image: https://storage.googleapis.com/syzbot-assets/04e89692a4c8/bzImage-9d590679.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ebea27...@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at fs/f2fs/inode.c:896!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 5938 Comm: syz-executor Not tainted 6.11.0-rc3-syzkaller-00036-g9d5906799f7d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:f2fs_evict_inode+0x1598/0x15c0 fs/f2fs/inode.c:896
Code: 2e b6 ab fd 31 ff 89 de e8 25 b6 ab fd 40 84 ed 75 28 e8 1b b3 ab fd e9 3c ec ff ff e8 11 b3 ab fd 90 0f 0b e8 09 b3 ab fd 90 <0f> 0b e8 01 b3 ab fd 90 0f 0b 90 e9 fc fe ff ff e8 f3 b2 ab fd e8
RSP: 0018:ffffc90009cf7928 EFLAGS: 00010293
RAX: ffffffff83e7c5c7 RBX: 0000000000000002 RCX: ffff888019f50000
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff83e7bfb0 R09: 1ffff1100b106843
R10: dffffc0000000000 R11: ffffed100b106844 R12: ffff888057150000
R13: ffff888058834218 R14: ffff888058833d78 R15: dffffc0000000000
FS: 0000555586684500(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcd737bd000 CR3: 0000000018b5c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
evict+0x532/0x950 fs/inode.c:704
dispose_list fs/inode.c:747 [inline]
evict_inodes+0x5f9/0x690 fs/inode.c:797
generic_shutdown_super+0x9d/0x2d0 fs/super.c:627
kill_block_super+0x44/0x90 fs/super.c:1696
kill_f2fs_super+0x344/0x690 fs/f2fs/super.c:4898
deactivate_locked_super+0xc4/0x130 fs/super.c:473
cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373
task_work_run+0x24f/0x310 kernel/task_work.c:228
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218
do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcd7cd7ad27
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe52115828 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fcd7cd7ad27
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe521158e0
RBP: 00007ffe521158e0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe52116960
R13: 00007fcd7cde778c R14: 0000000000021420 R15: 00007ffe521169a0
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:f2fs_evict_inode+0x1598/0x15c0 fs/f2fs/inode.c:896
Code: 2e b6 ab fd 31 ff 89 de e8 25 b6 ab fd 40 84 ed 75 28 e8 1b b3 ab fd e9 3c ec ff ff e8 11 b3 ab fd 90 0f 0b e8 09 b3 ab fd 90 <0f> 0b e8 01 b3 ab fd 90 0f 0b 90 e9 fc fe ff ff e8 f3 b2 ab fd e8
RSP: 0018:ffffc90009cf7928 EFLAGS: 00010293
RAX: ffffffff83e7c5c7 RBX: 0000000000000002 RCX: ffff888019f50000
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff83e7bfb0 R09: 1ffff1100b106843
R10: dffffc0000000000 R11: ffffed100b106844 R12: ffff888057150000
R13: ffff888058834218 R14: ffff888058833d78 R15: dffffc0000000000
FS: 0000555586684500(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcd737bd000 CR3: 0000000018b5c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 872cf28b8df9 Merge tag 'platform-drivers-x86-v6.11-4' of g..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=13ece38d980000
kernel config: https://syzkaller.appspot.com/x/.config?x=4fc2afd52fd008bb

dashboard link: https://syzkaller.appspot.com/bug?extid=ebea2790904673d7c618
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1344680b980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1034880b980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c63409516c62/disk-872cf28b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/79b2b8c52d3a/vmlinux-872cf28b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/27cb9df9c339/bzImage-872cf28b.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/1f04d7ef7499/mount_0.gz
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/831601ee93df/mount_5.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ebea27...@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at fs/f2fs/inode.c:896!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI

CPU: 1 UID: 0 PID: 5217 Comm: syz-executor605 Not tainted 6.11.0-rc4-syzkaller-00033-g872cf28b8df9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024

RIP: 0010:f2fs_evict_inode+0x1598/0x15c0 fs/f2fs/inode.c:896

Code: 6e 9b ab fd 31 ff 89 de e8 65 9b ab fd 40 84 ed 75 28 e8 5b 98 ab fd e9 3c ec ff ff e8 51 98 ab fd 90 0f 0b e8 49 98 ab fd 90 <0f> 0b e8 41 98 ab fd 90 0f 0b 90 e9 fc fe ff ff e8 33 98 ab fd e8
RSP: 0018:ffffc90003497808 EFLAGS: 00010293
RAX: ffffffff83e7f267 RBX: 0000000000000002 RCX: ffff88801a3e8000

RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000

RBP: 0000000000000000 R08: ffffffff83e7ec50 R09: 1ffff1100efe9611
R10: dffffc0000000000 R11: ffffed100efe9612 R12: ffff88807a834000
R13: ffff888077f4b088 R14: ffff888077f4abe8 R15: dffffc0000000000
FS: 000055556d6353c0(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000

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

CR2: 00007f376cbf9000 CR3: 00000000786a0000 CR4: 00000000003506f0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
evict+0x532/0x950 fs/inode.c:704
dispose_list fs/inode.c:747 [inline]
evict_inodes+0x5f9/0x690 fs/inode.c:797
generic_shutdown_super+0x9d/0x2d0 fs/super.c:627
kill_block_super+0x44/0x90 fs/super.c:1696
kill_f2fs_super+0x344/0x690 fs/f2fs/super.c:4898
deactivate_locked_super+0xc4/0x130 fs/super.c:473
cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373
task_work_run+0x24f/0x310 kernel/task_work.c:228

ptrace_notify+0x2d2/0x380 kernel/signal.c:2402
ptrace_report_syscall include/linux/ptrace.h:415 [inline]
ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline]
syscall_exit_work+0xc6/0x190 kernel/entry/common.c:173
syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline]
syscall_exit_to_user_mode+0x279/0x370 kernel/entry/common.c:218
do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f37740a00a7
Code: 08 00 48 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b0 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffc120a25e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000015fbb RCX: 00007f37740a00a7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc120a26a0
RBP: 00007ffc120a26a0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000206 R12: 00007ffc120a3750
R13: 000055556d636700 R14: 431bde82d7b634db R15: 00007ffc120a36f4

</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:f2fs_evict_inode+0x1598/0x15c0 fs/f2fs/inode.c:896

Code: 6e 9b ab fd 31 ff 89 de e8 65 9b ab fd 40 84 ed 75 28 e8 5b 98 ab fd e9 3c ec ff ff e8 51 98 ab fd 90 0f 0b e8 49 98 ab fd 90 <0f> 0b e8 41 98 ab fd 90 0f 0b 90 e9 fc fe ff ff e8 33 98 ab fd e8
RSP: 0018:ffffc90003497808 EFLAGS: 00010293
RAX: ffffffff83e7f267 RBX: 0000000000000002 RCX: ffff88801a3e8000

RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000

RBP: 0000000000000000 R08: ffffffff83e7ec50 R09: 1ffff1100efe9611
R10: dffffc0000000000 R11: ffffed100efe9612 R12: ffff88807a834000
R13: ffff888077f4b088 R14: ffff888077f4abe8 R15: dffffc0000000000
FS: 000055556d6353c0(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000

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

CR2: 00007f376bda6000 CR3: 00000000786a0000 CR4: 00000000003506f0

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


---

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

[Julian Sun]

Hi, all.

Recently syzbot reported a bug as following:

kernel BUG at fs/f2fs/inode.c:896!

CPU: 1 UID: 0 PID: 5217 Comm: syz-executor605 Not tainted 6.11.0-rc4-syzkaller-00033-g872cf28b8df9 #0

RIP: 0010:f2fs_evict_inode+0x1598/0x15c0 fs/f2fs/inode.c:896

Call Trace:
<TASK>
evict+0x532/0x950 fs/inode.c:704
dispose_list fs/inode.c:747 [inline]
evict_inodes+0x5f9/0x690 fs/inode.c:797
generic_shutdown_super+0x9d/0x2d0 fs/super.c:627
kill_block_super+0x44/0x90 fs/super.c:1696
kill_f2fs_super+0x344/0x690 fs/f2fs/super.c:4898
deactivate_locked_super+0xc4/0x130 fs/super.c:473
cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373
task_work_run+0x24f/0x310 kernel/task_work.c:228
ptrace_notify+0x2d2/0x380 kernel/signal.c:2402
ptrace_report_syscall include/linux/ptrace.h:415 [inline]
ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline]
syscall_exit_work+0xc6/0x190 kernel/entry/common.c:173
syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline]
syscall_exit_to_user_mode+0x279/0x370 kernel/entry/common.c:218
do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The syzbot constructed the following scenario: concurrently
creating directories and setting the file system to read-only.
In this case, while f2fs was making dir, the filesystem switched to
readonly, and when it tried to clear the dirty flag, it triggered this
code path: f2fs_mkdir()-> f2fs_sync_fs()->f2fs_write_checkpoint()
->f2fs_readonly(). This resulted FI_DIRTY_INODE flag not being cleared,
which eventually led to a bug being triggered during the FI_DIRTY_INODE
check in f2fs_evict_inode().

In this case, we cannot do anything further, so if filesystem is readonly,
do not trigger the BUG. Instead, clean up resources to the best of our
ability to prevent triggering subsequent resource leak checks.

If there is anything important I'm missing, please let me know, thanks.

Reported-by: syzbot+ebea27...@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=ebea2790904673d7c618
Fixes: ca7d802a7d8e ("f2fs: detect dirty inode in evict_inode")
CC: sta...@vger.kernel.org
Signed-off-by: Julian Sun <sunjunc...@gmail.com>
---
fs/f2fs/inode.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index aef57172014f..52d273383ec2 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -892,8 +892,12 @@ void f2fs_evict_inode(struct inode *inode)
atomic_read(&fi->i_compr_blocks));

if (likely(!f2fs_cp_error(sbi) &&
- !is_sbi_flag_set(sbi, SBI_CP_DISABLED)))
- f2fs_bug_on(sbi, is_inode_flag_set(inode, FI_DIRTY_INODE));
+ !is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
+ if (!f2fs_readonly(sbi->sb))
+ f2fs_bug_on(sbi, is_inode_flag_set(inode, FI_DIRTY_INODE));
+ else
+ f2fs_inode_synced(inode);
+ }
else
f2fs_inode_synced(inode);

--
2.39.2

[Jaegeuk Kim]

What about:

if (likely(!f2fs_cp_error(sbi) &&
!is_sbi_flag_set(sbi, SBI_CP_DISABLED)) &&
!f2fs_readonly(sbi->sb)))
f2fs_bug_on(sbi, is_inode_flag_set(inode, FI_DIRTY_INODE));
else
f2fs_inode_synced(inode);

>

>
> --
> 2.39.2

[Julian Sun]

Hi, Jaegeuk, thanks for your review.

Yeah, it is semantically identical, and the code is clearer.
I will fix it in patch v2.
>
> >
>
> >  
> > --
> > 2.39.2

[Chao Yu]

#syz test git://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git wip

[syzbot]

Hello,

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

Reported-by: syzbot+ebea27...@syzkaller.appspotmail.com
Tested-by: syzbot+ebea27...@syzkaller.appspotmail.com

Tested on:

commit: 69dc8fbb f2fs: get rid of online repaire on corrupted ..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git wip
console output: https://syzkaller.appspot.com/x/log.txt?x=166e6963980000
kernel config: https://syzkaller.appspot.com/x/.config?x=9358cc4a2e37fd30

dashboard link: https://syzkaller.appspot.com/bug?extid=ebea2790904673d7c618
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Note: no patches were applied.
Note: testing is done by a robot and is best-effort only.