Re: [syzbot] [f2fs?] WARNING: lock held when returning to user space in f2fs_write_single_data_page

syzbot
2023-05-03T16:08:23Z

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
general protection fault in f2fs_quota_on

general protection fault, probably for non-canonical address 0xdffffc00000000e6: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000730-0x0000000000000737]
CPU: 0 PID: 5450 Comm: syz-executor.0 Not tainted 6.3.0-syzkaller-05651-gfd78b242ba1b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
RIP: 0010:__lock_acquire+0x69/0x2000 kernel/locking/lockdep.c:4942
Code: df 0f b6 04 30 84 c0 0f 85 5a 16 00 00 83 3d c1 51 e9 0c 00 0f 84 02 11 00 00 83 3d f0 89 74 0b 00 74 2b 4c 89 f0 48 c1 e8 03 <80> 3c 30 00 74 12 4c 89 f7 e8 c9 54 76 00 48 be 00 00 00 00 00 fc
RSP: 0018:ffffc90005a1faf8 EFLAGS: 00010002
RAX: 00000000000000e6 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000000730
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000730 R15: ffff888077f13b80
FS: 00007fc1c2b17700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055800180a000 CR3: 00000000706b1000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5691
down_write+0x3a/0x50 kernel/locking/rwsem.c:1573
f2fs_down_write fs/f2fs/f2fs.h:2125 [inline]
f2fs_quota_on+0x120/0x320 fs/f2fs/super.c:2916
__do_sys_quotactl fs/quota/quota.c:960 [inline]
__se_sys_quotactl+0x2b5/0x810 fs/quota/quota.c:916
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc1c1e8c169
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc1c2b17168 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fc1c1fac050 RCX: 00007fc1c1e8c169
RDX: 0000000000000000 RSI: 0000000020000080 RDI: ffffffff80000202
RBP: 00007fc1c1ee7ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020008040 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd3e2e112f R14: 00007fc1c2b17300 R15: 0000000000022000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__lock_acquire+0x69/0x2000 kernel/locking/lockdep.c:4942
Code: df 0f b6 04 30 84 c0 0f 85 5a 16 00 00 83 3d c1 51 e9 0c 00 0f 84 02 11 00 00 83 3d f0 89 74 0b 00 74 2b 4c 89 f0 48 c1 e8 03 <80> 3c 30 00 74 12 4c 89 f7 e8 c9 54 76 00 48 be 00 00 00 00 00 fc
RSP: 0018:ffffc90005a1faf8 EFLAGS: 00010002
RAX: 00000000000000e6 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000000730
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000730 R15: ffff888077f13b80
FS: 00007fc1c2b17700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055800180a000 CR3: 00000000706b1000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: df 0f fisttps (%rdi)
2: b6 04 mov $0x4,%dh
4: 30 84 c0 0f 85 5a 16 xor %al,0x165a850f(%rax,%rax,8)
b: 00 00 add %al,(%rax)
d: 83 3d c1 51 e9 0c 00 cmpl $0x0,0xce951c1(%rip) # 0xce951d5
14: 0f 84 02 11 00 00 je 0x111c
1a: 83 3d f0 89 74 0b 00 cmpl $0x0,0xb7489f0(%rip) # 0xb748a11
21: 74 2b je 0x4e
23: 4c 89 f0 mov %r14,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 80 3c 30 00 cmpb $0x0,(%rax,%rsi,1) <-- trapping instruction
2e: 74 12 je 0x42
30: 4c 89 f7 mov %r14,%rdi
33: e8 c9 54 76 00 callq 0x765501
38: 48 rex.W
39: be 00 00 00 00 mov $0x0,%esi
3e: 00 fc add %bh,%ah

Tested on:

commit: fd78b242 f2fs: fix potential deadlock due to unpaired ..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git dev-test
console output: https://syzkaller.appspot.com/x/log.txt?x=11d46838280000
kernel config: https://syzkaller.appspot.com/x/.config?x=86e4eb913e90d4b2
dashboard link: https://syzkaller.appspot.com/bug?extid=eb6201248f684e99b9f8
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

Note: no patches were applied.