[v6.6] BUG: MAX_LOCK_DEPTH too low!

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: f34f16e5c632 Linux 6.6.109
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=107ea92f980000
kernel config: https://syzkaller.appspot.com/x/.config?x=12606d4b8832c7e4
dashboard link: https://syzkaller.appspot.com/bug?extid=794b5787fd2a267cb4c2
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1d84cf343aca/disk-f34f16e5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/613ae177a403/vmlinux-f34f16e5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6b9016970cbc/bzImage-f34f16e5.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+794b57...@syzkaller.appspotmail.com

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48 max: 48!
48 locks held by syz.9.2729/15779:
#0: ffff88804db52190 (&sb->s_type->i_mutex_key#35){++++}-{3:3}, at: inode_trylock include/linux/fs.h:824 [inline]
#0: ffff88804db52190 (&sb->s_type->i_mutex_key#35){++++}-{3:3}, at: btrfs_inode_lock+0x8d/0xe0 fs/btrfs/inode.c:372
#1: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#2: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#3: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#4: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#5: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#6: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#7: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#8: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#9: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#10: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#11: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#12: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#13: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#14: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#15: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#16: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#17: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#18: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#19: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#20: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#21: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#22: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#23: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#24: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#25: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#26: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#27: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#28: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#29: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#30: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#31: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#32: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#33: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#34: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#35: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#36: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#37: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#38: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#39: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#40: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#41: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#42: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#43: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#44: ffff88805d3e4850 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#45: ffff88805d3e43e8 (&eb->refs_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#45: ffff88805d3e43e8 (&eb->refs_lock){+.+.}-{2:2}, at: free_extent_buffer+0x263/0x420 fs/btrfs/extent_io.c:3935
#46: ffff8880b8f2b718 (hrtimer_bases.lock){-.-.}-{2:2}, at: hrtimer_interrupt+0xfc/0x9c0 kernel/time/hrtimer.c:1857
#47: ffffffff8cd49988 (tk_core.seq.seqcount){----}-{0:0}, at: ktime_get_update_offsets_now+0x48/0x3f0 kernel/time/timekeeping.c:2317
INFO: lockdep is turned off.
CPU: 1 PID: 15779 Comm: syz.9.2729 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
<IRQ>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
__lock_acquire+0x1ba4/0x7c80 kernel/locking/lockdep.c:-1
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
seqcount_lockdep_reader_access+0xca/0x1c0 include/linux/seqlock.h:102
ktime_get_update_offsets_now+0x48/0x3f0 kernel/time/timekeeping.c:2317
hrtimer_update_base kernel/time/hrtimer.c:661 [inline]
hrtimer_interrupt+0x134/0x9c0 kernel/time/hrtimer.c:1858
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
__sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:lock_acquire+0x1f2/0x410 kernel/locking/lockdep.c:5758
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00
RSP: 0018:ffffc90004b86ec0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 20c6d7875e917000
RDX: 0000000000000001 RSI: ffffffff8aaace60 RDI: ffffffff8afc63c0
RBP: ffffc90004b86fd8 R08: dffffc0000000000 R09: 1ffffffff21b4edb
R10: dffffc0000000000 R11: fffffbfff21b4edc R12: 1ffff92000970de4
R13: ffff88805d3e43e8 R14: 0000000000000246 R15: dffffc0000000000
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
free_extent_buffer+0x263/0x420 fs/btrfs/extent_io.c:3935
read_block_for_search+0x5b5/0x990 fs/btrfs/ctree.c:1708
btrfs_search_slot+0x109a/0x27e0 fs/btrfs/ctree.c:2355
btrfs_lookup_file_extent+0xd9/0x120 fs/btrfs/file-item.c:270
can_nocow_extent+0x1bb/0x810 fs/btrfs/inode.c:7093
btrfs_check_nocow_lock+0x245/0x3a0 fs/btrfs/file.c:1092
btrfs_buffered_write+0x559/0x1130 fs/btrfs/file.c:1265
btrfs_do_write_iter+0x24b/0x11b0 fs/btrfs/file.c:1689
call_write_iter include/linux/fs.h:2018 [inline]
aio_write+0x53c/0x790 fs/aio.c:1593
__io_submit_one fs/aio.c:-1 [inline]
io_submit_one+0x70b/0x1240 fs/aio.c:2012
__do_sys_io_submit fs/aio.c:2071 [inline]
__se_sys_io_submit+0x194/0x300 fs/aio.c:2041
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd16e58eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd16f3d3038 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1
RAX: ffffffffffffffda RBX: 00007fd16e7e6180 RCX: 00007fd16e58eec9
RDX: 0000200000000540 RSI: 0000000000000001 RDI: 00007fd16f3f5000
RBP: 00007fd16e611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd16e7e6218 R14: 00007fd16e7e6180 R15: 00007ffc03fe6aa8
</TASK>
----------------
Code disassembly (best guess):
0: 00 9c 8f 84 24 80 00 add %bl,0x802484(%rdi,%rcx,4)
7: 00 00 add %al,(%rax)
9: f6 84 24 81 00 00 00 testb $0x2,0x81(%rsp)
10: 02
11: 0f 85 f5 00 00 00 jne 0x10c
17: 41 f7 c6 00 02 00 00 test $0x200,%r14d
1e: 74 01 je 0x21
20: fb sti
21: 48 c7 44 24 60 0e 36 movq $0x45e0360e,0x60(%rsp)
28: e0 45
* 2a: 4b c7 04 3c 00 00 00 movq $0x0,(%r12,%r15,1) <-- trapping instruction
31: 00
32: 66 43 c7 44 3c 09 00 movw $0x0,0x9(%r12,%r15,1)
39: 00
3a: 43 c6 44 3c 0b 00 movb $0x0,0xb(%r12,%r15,1)


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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: f34f16e5c632 Linux 6.6.109
git tree: linux-6.6.y

console output: https://syzkaller.appspot.com/x/log.txt?x=12cb8892580000

kernel config: https://syzkaller.appspot.com/x/.config?x=12606d4b8832c7e4
dashboard link: https://syzkaller.appspot.com/bug?extid=794b5787fd2a267cb4c2
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11700ee2580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14a4b214580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1d84cf343aca/disk-f34f16e5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/613ae177a403/vmlinux-f34f16e5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6b9016970cbc/bzImage-f34f16e5.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/2deb2ae84ecc/mount_1.gz
fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=1392ea7c580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+794b57...@syzkaller.appspotmail.com

BTRFS warning (device loop1: state EA): Skipping commit of aborted transaction.
BTRFS: error (device loop1: state EA) in cleanup_transaction:2004: errno=-5 IO failure

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48 max: 48!

48 locks held by syz.1.18/5948:
#0: ffff88805d298ef0 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: inode_trylock include/linux/fs.h:824 [inline]
#0: ffff88805d298ef0 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: btrfs_inode_lock+0x8d/0xe0 fs/btrfs/inode.c:372
#1: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#2: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#3: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#4: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#5: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#6: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#7: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#8: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#9: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#10: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#11: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#12: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#13: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#14: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#15: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#16: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#17: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#18: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#19: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#20: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#21: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#22: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#23: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#24: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#25: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#26: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#27: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#28: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#29: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#30: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#31: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#32: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#33: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#34: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#35: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#36: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#37: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#38: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#39: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#40: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#41: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#42: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#43: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#44: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#45: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#46: ffff8880315e82c8 (btrfs-tree-01){++++}-{3:3}, at: btrfs_try_tree_read_lock+0x1e/0x1f0 fs/btrfs/locking.c:152
#47: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#47: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#47: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: find_extent_buffer_nolock+0x21/0x320 fs/btrfs/extent_io.c:1637

INFO: lockdep is turned off.

CPU: 1 PID: 5948 Comm: syz.1.18 Not tainted syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:

<TASK>

dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
__lock_acquire+0x1ba4/0x7c80 kernel/locking/lockdep.c:-1
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754

rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
rcu_read_lock include/linux/rcupdate.h:786 [inline]
find_extent_buffer_nolock+0x3d/0x320 fs/btrfs/extent_io.c:1637
find_extent_buffer+0x24/0x1a0 fs/btrfs/extent_io.c:3594
read_block_for_search+0x2eb/0x990 fs/btrfs/ctree.c:1686

btrfs_search_slot+0x109a/0x27e0 fs/btrfs/ctree.c:2355
btrfs_lookup_file_extent+0xd9/0x120 fs/btrfs/file-item.c:270
can_nocow_extent+0x1bb/0x810 fs/btrfs/inode.c:7093
btrfs_check_nocow_lock+0x245/0x3a0 fs/btrfs/file.c:1092
btrfs_buffered_write+0x559/0x1130 fs/btrfs/file.c:1265
btrfs_do_write_iter+0x24b/0x11b0 fs/btrfs/file.c:1689
call_write_iter include/linux/fs.h:2018 [inline]
aio_write+0x53c/0x790 fs/aio.c:1593
__io_submit_one fs/aio.c:-1 [inline]
io_submit_one+0x70b/0x1240 fs/aio.c:2012
__do_sys_io_submit fs/aio.c:2071 [inline]
__se_sys_io_submit+0x194/0x300 fs/aio.c:2041
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2

RIP: 0033:0x7fb5e878eec9

Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48

RSP: 002b:00007ffe7dc7f1c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1
RAX: ffffffffffffffda RBX: 00007fb5e89e5fa0 RCX: 00007fb5e878eec9
RDX: 0000200000000540 RSI: 0000000000000001 RDI: 00007fb5e95b9000
RBP: 00007fb5e8811f91 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 00007fb5e89e5fa0 R14: 00007fb5e89e5fa0 R15: 0000000000000003
</TASK>


---
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