[syzbot] [ext4?] WARNING in ext4_mb_initialize_context

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Jun 5, 2024, 3:47:36 PMJun 5
to adilger...@dilger.ca, linux...@vger.kernel.org, linux-...@vger.kernel.org, syzkall...@googlegroups.com, ty...@mit.edu
Hello,

syzbot found the following issue on:

HEAD commit: cc8ed4d0a848 Merge tag 'drm-fixes-2024-06-01' of https://g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=131d0e16980000
kernel config: https://syzkaller.appspot.com/x/.config?x=733cc7a95171d8e7
dashboard link: https://syzkaller.appspot.com/bug?extid=176b58b1d4ea28b1c947
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-cc8ed4d0.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/36abdd995432/vmlinux-cc8ed4d0.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5e4e0a6f67db/bzImage-cc8ed4d0.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+176b58...@syzkaller.appspotmail.com

------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: CPU: 2 PID: 5763 at kernel/locking/mutex.c:587 __mutex_lock_common kernel/locking/mutex.c:587 [inline]
WARNING: CPU: 2 PID: 5763 at kernel/locking/mutex.c:587 __mutex_lock+0x328/0x9c0 kernel/locking/mutex.c:752
Modules linked in:
CPU: 2 PID: 5763 Comm: syz-executor.2 Not tainted 6.10.0-rc1-syzkaller-00267-gcc8ed4d0a848 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:587 [inline]
RIP: 0010:__mutex_lock+0x328/0x9c0 kernel/locking/mutex.c:752
Code: d0 7c 08 84 d2 0f 85 50 06 00 00 8b 0d 25 df 03 05 85 c9 75 19 90 48 c7 c6 60 a4 2c 8b 48 c7 c7 c0 a2 2c 8b e8 09 ef 71 f6 90 <0f> 0b 90 90 90 e9 0d fe ff ff 4c 8d b5 60 ff ff ff 48 89 df 4c 89
RSP: 0018:ffffc90002eeee80 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffffe8ffad251290 RCX: ffffc9000c001000
RDX: 0000000000040000 RSI: ffffffff81510236 RDI: 0000000000000001
RBP: ffffc90002eeefa0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 000000002d2d2d2d R12: 1ffff920005dddda
R13: 0000000000000002 R14: dffffc0000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88802c200000(0063) knlGS:00000000f5eb4b40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f73fd584 CR3: 0000000025738000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ext4_mb_group_or_file fs/ext4/mballoc.c:5788 [inline]
ext4_mb_initialize_context+0x814/0xdf0 fs/ext4/mballoc.c:5832
ext4_mb_new_blocks+0x96d/0x4e40 fs/ext4/mballoc.c:6206
ext4_alloc_branch fs/ext4/indirect.c:340 [inline]
ext4_ind_map_blocks+0x19fb/0x2810 fs/ext4/indirect.c:635
ext4_map_blocks+0x878/0x17d0 fs/ext4/inode.c:625
_ext4_get_block+0x250/0x5a0 fs/ext4/inode.c:765
__block_write_begin_int+0x4fb/0x16e0 fs/buffer.c:2128
ext4_convert_inline_data_to_extent fs/ext4/inline.c:607 [inline]
ext4_try_to_write_inline_data+0x5ec/0x1350 fs/ext4/inline.c:739
ext4_write_begin+0xc6f/0x1140 fs/ext4/inode.c:1143
generic_perform_write+0x272/0x620 mm/filemap.c:4015
ext4_buffered_write_iter+0x11f/0x3d0 fs/ext4/file.c:299
ext4_file_write_iter+0x874/0x1a40 fs/ext4/file.c:698
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0x6b6/0x1140 fs/read_write.c:590
ksys_pwrite64+0x176/0x1a0 fs/read_write.c:705
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf72c2579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f5eb45ac EFLAGS: 00000292
ORIG_RAX: 00000000000000b5
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 0000000020000140
RDX: 000000000000fdef RSI: 0000000008000c61 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
0: 10 06 adc %al,(%rsi)
2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi
6: 10 07 adc %al,(%rdi)
8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi
c: 10 08 adc %cl,(%rax)
e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi
1e: 00 51 52 add %dl,0x52(%rcx)
21: 55 push %rbp
22: 89 e5 mov %esp,%ebp
24: 0f 34 sysenter
26: cd 80 int $0x80
* 28: 5d pop %rbp <-- trapping instruction
29: 5a pop %rdx
2a: 59 pop %rcx
2b: c3 ret
2c: 90 nop
2d: 90 nop
2e: 90 nop
2f: 90 nop
30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi


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