[syzbot] [ext4?] WARNING: locking bug in ext4_mb_add_groupinfo

From: syzbot
Date: Sat May 18 2024 - 01:23:34 EST

Hello,

syzbot found the following issue on:

HEAD commit: a5131c3fdf26 Merge tag 'x86-shstk-2024-05-13' of git://git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=152fcf98980000
kernel config: https://syzkaller.appspot.com/x/.config?x=fdb182f40cdd66f7
dashboard link: https://syzkaller.appspot.com/bug?extid=caf3fed221ac23a1398f
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-a5131c3f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6d23116dab9c/vmlinux-a5131c3f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/dd8b9de9af4f/bzImage-a5131c3f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+caf3fed221ac23a1398f@xxxxxxxxxxxxxxxxxxxxxxxxx

Looking for class "c->lock" with key __key.0, but found a different class "&c->lock" with the same key
WARNING: CPU: 3 PID: 5490 at kernel/locking/lockdep.c:932 look_up_lock_class+0x133/0x140 kernel/locking/lockdep.c:932
Modules linked in:
CPU: 3 PID: 5490 Comm: syz-executor.1 Not tainted 6.9.0-syzkaller-01768-ga5131c3fdf26 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:look_up_lock_class+0x133/0x140 kernel/locking/lockdep.c:932
Code: c7 c7 80 bc 0c 8b e8 9c a3 7d f6 90 0f 0b 90 90 90 31 db eb be c6 05 78 f3 b3 04 01 90 48 c7 c7 a0 bf 0c 8b e8 7e a3 7d f6 90 <0f> 0b 90 90 e9 62 ff ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900076bf4d8 EFLAGS: 00010086
RAX: 0000000000000000 RBX: ffffffff93d7a900 RCX: ffffc90006f69000
RDX: 0000000000040000 RSI: ffffffff81514aa6 RDI: 0000000000000001
RBP: ffffffff9466e9d0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 000000006b6f6f4c R12: ffffe8ffad57d2c0
R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff94656ba0
FS: 0000000000000000(0000) GS:ffff88802c500000(0063) knlGS:00000000f5e47b40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f73d30c4 CR3: 00000000003a6000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
register_lock_class+0xb1/0x1230 kernel/locking/lockdep.c:1284
__lock_acquire+0x111/0x3b30 kernel/locking/lockdep.c:5014
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
___slab_alloc+0x73b/0x1810 mm/slub.c:3641
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3682
__slab_alloc_node mm/slub.c:3735 [inline]
slab_alloc_node mm/slub.c:3908 [inline]
kmem_cache_alloc+0x2f3/0x330 mm/slub.c:3925
kmem_cache_zalloc include/linux/slab.h:739 [inline]
ext4_mb_add_groupinfo+0x43f/0x1180 fs/ext4/mballoc.c:3343
ext4_mb_init_backend fs/ext4/mballoc.c:3422 [inline]
ext4_mb_init+0x1273/0x2530 fs/ext4/mballoc.c:3719
__ext4_fill_super fs/ext4/super.c:5518 [inline]
ext4_fill_super+0x6e08/0xaea0 fs/ext4/super.c:5695
get_tree_bdev+0x36f/0x610 fs/super.c:1614
vfs_get_tree+0x8f/0x380 fs/super.c:1779
do_new_mount fs/namespace.c:3352 [inline]
path_mount+0x6e1/0x1f10 fs/namespace.c:3679
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount fs/namespace.c:3875 [inline]
__ia32_sys_mount+0x295/0x320 fs/namespace.c:3875
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x75/0x120 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: 0023:0xf7255579
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:00000000f5e47400 EFLAGS: 00000292 ORIG_RAX: 0000000000000015
RAX: ffffffffffffffda RBX: 00000000f5e47460 RCX: 00000000200005c0
RDX: 0000000020000100 RSI: 0000000001018e58 RDI: 00000000f5e474a0
RBP: 00000000f5e47460 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 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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