Re: [syzbot] [bcachefs?] WARNING: locking bug in rcu_pending_pcpu_dequeue

[syzbot <syzbot+e103923b16da1cda0ae0@syzkaller.appspotmail.com>]

syzbot has found a reproducer for the following issue on:

HEAD commit:    619f0b6fad52 Merge tag 'seccomp-v6.13-rc8' of git://git.ke..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10fc87c4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c676c8e1379fdfaa
dashboard link: https://syzkaller.appspot.com/bug?extid=e103923b16da1cda0ae0
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=14f36a18580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a9c9c3056af4/disk-619f0b6f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/558f94c52108/vmlinux-619f0b6f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/595b7ae81ee0/bzImage-619f0b6f.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/57adb1b0a2e2/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e103923b16da1cda0ae0@syzkaller.appspotmail.com

bcachefs (loop2): stripes_read... done
bcachefs (loop2): snapshots_read... done
bcachefs (loop2): check_allocations...
------------[ cut here ]------------
Looking for class "" with key rcu_pending_init.__key, but found a different class "&p->lock" with the same key
WARNING: CPU: 0 PID: 7205 at kernel/locking/lockdep.c:939 look_up_lock_class+0xdc/0x170 kernel/locking/lockdep.c:936
Modules linked in:
CPU: 0 UID: 0 PID: 7205 Comm: syz.2.134 Not tainted 6.13.0-rc7-syzkaller-00043-g619f0b6fad52 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:look_up_lock_class+0xdc/0x170 kernel/locking/lockdep.c:936
Code: 01 0f 85 8a 00 00 00 c6 05 c4 7d 41 04 01 90 49 8b 16 49 8b 76 18 48 8b 8b b8 00 00 00 48 c7 c7 60 ba 0a 8c e8 15 07 9f f5 90 <0f> 0b 90 90 eb 61 90 e8 68 de f5 f8 e8 63 69 be f5 48 c7 c7 a0 b9
RSP: 0018:ffffc90003bcd870 EFLAGS: 00010046
RAX: 5e4db7495586dc00 RBX: ffffffff93c599c8 RCX: ffff888031bd1e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003bcd980 R08: ffffffff816019e2 R09: 1ffff110170c519a
R10: dffffc0000000000 R11: ffffed10170c519b R12: ffffe8ffffc3f830
R13: ffffe8ffffc3f830 R14: ffffe8ffffc3f830 R15: ffffffff9a51dcc0
FS:  00007ff8886426c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f05ef09a000 CR3: 0000000033d02000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 register_lock_class+0x102/0x980 kernel/locking/lockdep.c:1290
 __lock_acquire+0xf3/0x2100 kernel/locking/lockdep.c:5101
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
 _raw_spin_lock_irq+0xd3/0x120 kernel/locking/spinlock.c:170
 spin_lock_irq include/linux/spinlock.h:376 [inline]
 rcu_pending_pcpu_dequeue+0x29/0x2b0 fs/bcachefs/rcu_pending.c:522
 bkey_cached_alloc fs/bcachefs/btree_key_cache.c:143 [inline]
 btree_key_cache_create fs/bcachefs/btree_key_cache.c:220 [inline]
 btree_key_cache_fill+0x43a/0x2920 fs/bcachefs/btree_key_cache.c:309
 bch2_btree_path_traverse_cached+0x84e/0xbe0 fs/bcachefs/btree_key_cache.c:361
 bch2_btree_path_traverse_one+0x45d/0x2940 fs/bcachefs/btree_iter.c:1159
 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:247 [inline]
 bch2_trans_update_get_key_cache+0x6c0/0x1220 fs/bcachefs/btree_update.c:494
 bch2_trans_update+0x9b1/0x2550 fs/bcachefs/btree_update.c:539
 bch2_alloc_write_key fs/bcachefs/btree_gc.c:887 [inline]
 bch2_gc_alloc_done fs/bcachefs/btree_gc.c:897 [inline]
 bch2_check_allocations+0x4344/0x7070 fs/bcachefs/btree_gc.c:1139
 bch2_run_recovery_pass+0xf0/0x1e0 fs/bcachefs/recovery_passes.c:191
 bch2_run_recovery_passes+0x3a7/0x880 fs/bcachefs/recovery_passes.c:244
 bch2_fs_recovery+0x25cc/0x39d0 fs/bcachefs/recovery.c:861
 bch2_fs_start+0x356/0x5b0 fs/bcachefs/super.c:1037
 bch2_fs_get_tree+0xd68/0x1710 fs/bcachefs/fs.c:2170
 vfs_get_tree+0x90/0x2b0 fs/super.c:1814
 do_new_mount+0x2be/0xb40 fs/namespace.c:3511
 do_mount fs/namespace.c:3851 [inline]
 __do_sys_mount fs/namespace.c:4061 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4038
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff8877874ca
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff888641e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff888641ef0 RCX: 00007ff8877874ca
RDX: 0000000020000380 RSI: 0000000020000340 RDI: 00007ff888641eb0
RBP: 0000000020000380 R08: 00007ff888641ef0 R09: 0000000000800000
R10: 0000000000800000 R11: 0000000000000246 R12: 0000000020000340
R13: 00007ff888641eb0 R14: 0000000000005919 R15: 00000000200001c0
 </TASK>


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