Message-ID: <671d9032.050a0220.2fdf0c.0231.GAE@google.com>
Date: Sat, 26 Oct 2024 17:58:26 -0700
From: syzbot <syzbot+883742a0b3b485018df5@...kaller.appspotmail.com>
To: adilger.kernel@...ger.ca, linux-ext4@...r.kernel.org, 
	linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com, tytso@....edu
Subject: [syzbot] [ext4?] WARNING: locking bug in ext4_mb_add_groupinfo (2)

Hello,

syzbot found the following issue on:

HEAD commit:    526116b79e8c KVM: arm64: Shave a few bytes from the EL2 id..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=15cf0c30580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e39b0b4b1ace5bc0
dashboard link: https://syzkaller.appspot.com/bug?extid=883742a0b3b485018df5
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2f7b2b08fdad/disk-526116b7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b69595b63015/vmlinux-526116b7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/39fd415ada60/Image-526116b7.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+883742a0b3b485018df5@...kaller.appspotmail.com

loop4: detected capacity change from 0 to 2048
------------[ cut here ]------------
Looking for class "c->lock" with key init_kmem_cache_cpus.__key, but found a different class "&c->lock" with the same key
WARNING: CPU: 0 PID: 7531 at kernel/locking/lockdep.c:939 look_up_lock_class+0xec/0x160 kernel/locking/lockdep.c:936
Modules linked in:
CPU: 0 UID: 0 PID: 7531 Comm: syz.4.213 Not tainted 6.12.0-rc4-syzkaller-g526116b79e8c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : look_up_lock_class+0xec/0x160 kernel/locking/lockdep.c:936
lr : look_up_lock_class+0xec/0x160 kernel/locking/lockdep.c:936
sp : ffff8000a1546ec0
x29: ffff8000a1546ec0 x28: dfff800000000000 x27: 0000000000000000
x26: ffff800097322640 x25: ffff800097322000 x24: 0000000000000001
x23: 0000000000000000 x22: 1ffff00011f000ba x21: ffff8000973833d0
x20: fffffdffbf6e2360 x19: ffff800092df5330 x18: 0000000000000008
x17: 2c79656b5f5f2e73 x16: ffff8000830c7d0c x15: 0000000000000001
x14: 1fffe000366c74e2 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000040000 x10: 000000000000e48f x9 : 4747ec9eeb91e600
x8 : 4747ec9eeb91e600 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff8000a15465f8 x4 : ffff80008f8ed8a0 x3 : ffff80008062a854
x2 : 0000000000000001 x1 : 0000000100000001 x0 : 0000000000000000
Call trace:
 look_up_lock_class+0xec/0x160 kernel/locking/lockdep.c:936 (P)
 look_up_lock_class+0xec/0x160 kernel/locking/lockdep.c:936 (L)
 register_lock_class+0x8c/0x6b4 kernel/locking/lockdep.c:1290
 __lock_acquire+0x18c/0x77c8 kernel/locking/lockdep.c:5077
 lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5825
 local_lock_acquire+0x3c/0x98 include/linux/local_lock_internal.h:29
 ___slab_alloc+0xcd0/0xf4c mm/slub.c:3867
 __slab_alloc+0x74/0xd0 mm/slub.c:3908
 __slab_alloc_node mm/slub.c:3961 [inline]
 slab_alloc_node mm/slub.c:4122 [inline]
 kmem_cache_alloc_noprof+0x26c/0x354 mm/slub.c:4141
 ext4_mb_add_groupinfo+0x5b8/0xdc4 fs/ext4/mballoc.c:3356
 ext4_mb_init_backend fs/ext4/mballoc.c:3435 [inline]
 ext4_mb_init+0x107c/0x1ff4 fs/ext4/mballoc.c:3733
 __ext4_fill_super fs/ext4/super.c:5512 [inline]
 ext4_fill_super+0x4b48/0x57c8 fs/ext4/super.c:5686
 get_tree_bdev+0x320/0x470 fs/super.c:1635
 ext4_get_tree+0x28/0x38 fs/ext4/super.c:5718
 vfs_get_tree+0x90/0x28c fs/super.c:1800
 do_new_mount+0x278/0x900 fs/namespace.c:3507
 path_mount+0x590/0xe04 fs/namespace.c:3834
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4055 [inline]
 __se_sys_mount fs/namespace.c:4032 [inline]
 __arm64_sys_mount+0x45c/0x5a8 fs/namespace.c:4032
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
irq event stamp: 4990
hardirqs last  enabled at (4989): [<ffff800080a12d48>] seqcount_lockdep_reader_access+0x6c/0xd4 include/linux/seqlock.h:74
hardirqs last disabled at (4990): [<ffff800080a2fa14>] ___slab_alloc+0xca4/0xf4c mm/slub.c:3867
softirqs last  enabled at (4320): [<ffff80008003084c>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (4318): [<ffff800080030818>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---
EXT4-fs (loop4): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.


---
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