======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
kworker/u8:1/13 is trying to acquire lock:
ffff88807a01bf70 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf2/0x15e0 fs/hfs/extent.c:397
but task is already holding lock:
ffff88803373c0a8 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&tree->tree_lock/1){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:632 [inline]
__mutex_lock+0x19e/0x1420 kernel/locking/mutex.c:794
hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1
hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
hfs_get_block+0x556/0xc50 fs/hfs/extent.c:366
block_read_full_folio+0x29f/0x830 fs/buffer.c:2417
filemap_read_folio+0x137/0x3b0 mm/filemap.c:2502
do_read_cache_folio+0x358/0x590 mm/filemap.c:4107
do_read_cache_page mm/filemap.c:4173 [inline]
read_cache_page+0x5d/0x170 mm/filemap.c:4182
read_mapping_page include/linux/pagemap.h:1022 [inline]
__hfs_bnode_create+0x4b9/0x980 fs/hfs/bnode.c:388
hfs_bnode_find+0x211/0xd40 fs/hfs/bnode.c:433
hfs_brec_find+0x17b/0x510 fs/hfs/bfind.c:135
hfs_brec_read+0x24/0x110 fs/hfs/bfind.c:174
hfs_cat_find_brec+0x177/0x3f0 fs/hfs/catalog.c:194
hfs_fill_super+0x4ff/0x770 fs/hfs/super.c:357
get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
vfs_get_tree+0x92/0x2a0 fs/super.c:1754
fc_mount fs/namespace.c:1193 [inline]
do_new_mount_fc fs/namespace.c:3764 [inline]
do_new_mount+0x341/0xd30 fs/namespace.c:3840
do_mount fs/namespace.c:4173 [inline]
__do_sys_mount fs/namespace.c:4372 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4349
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/mutex.c:632 [inline]
__mutex_lock+0x19e/0x1420 kernel/locking/mutex.c:794
hfs_extend_file+0xf2/0x15e0 fs/hfs/extent.c:397
hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269
__hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121
hfs_ext_write_extent+0x17e/0x210 fs/hfs/extent.c:144
hfs_write_inode+0x117/0x960 fs/hfs/inode.c:459
write_inode fs/fs-writeback.c:1582 [inline]
__writeback_single_inode+0x75a/0x11a0 fs/fs-writeback.c:1813
writeback_sb_inodes+0x992/0x1a20 fs/fs-writeback.c:2042
wb_writeback+0x456/0xb70 fs/fs-writeback.c:2227
wb_do_writeback fs/fs-writeback.c:2374 [inline]
wb_workfn+0x414/0xf50 fs/fs-writeback.c:2414
process_one_work+0x9ab/0x1780 kernel/workqueue.c:3288
process_scheduled_works kernel/workqueue.c:3379 [inline]
worker_thread+0xba8/0x11e0 kernel/workqueue.c:3465
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&tree->tree_lock/1);
lock(&HFS_I(tree->inode)->extents_lock);
lock(&tree->tree_lock/1);
lock(&HFS_I(tree->inode)->extents_lock);
*** DEADLOCK ***
3 locks held by kworker/u8:1/13:
#0: ffff8880206c6140 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x894/0x1780 kernel/workqueue.c:3260
#1: ffffc90000127c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1780 kernel/workqueue.c:3261
#2: ffff88803373c0a8 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1
stack backtrace:
CPU: 1 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: writeback wb_workfn (flush-7:2)
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043
check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/mutex.c:632 [inline]
__mutex_lock+0x19e/0x1420 kernel/locking/mutex.c:794
hfs_extend_file+0xf2/0x15e0 fs/hfs/extent.c:397
hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269
__hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121
hfs_ext_write_extent+0x17e/0x210 fs/hfs/extent.c:144
hfs_write_inode+0x117/0x960 fs/hfs/inode.c:459
write_inode fs/fs-writeback.c:1582 [inline]
__writeback_single_inode+0x75a/0x11a0 fs/fs-writeback.c:1813
writeback_sb_inodes+0x992/0x1a20 fs/fs-writeback.c:2042
wb_writeback+0x456/0xb70 fs/fs-writeback.c:2227
wb_do_writeback fs/fs-writeback.c:2374 [inline]
wb_workfn+0x414/0xf50 fs/fs-writeback.c:2414
process_one_work+0x9ab/0x1780 kernel/workqueue.c:3288
process_scheduled_works kernel/workqueue.c:3379 [inline]
worker_thread+0xba8/0x11e0 kernel/workqueue.c:3465
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
hfs: new node 0 already hashed?
------------[ cut here ]------------
1
WARNING: fs/hfs/bnode.c:520 at hfs_bnode_create+0x461/0x4f0 fs/hfs/bnode.c:520, CPU#1: kworker/u8:1/13
Modules linked in:
CPU: 1 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: writeback wb_workfn (flush-7:2)
RIP: 0010:hfs_bnode_create+0x461/0x4f0 fs/hfs/bnode.c:520
Code: e8 8b 89 ee e8 60 cc 78 fe e9 cf fc ff ff e8 06 be 17 ff 4c 89 ef e8 be 72 08 09 48 c7 c7 c0 12 e8 8b 89 ee e8 40 cc 78 fe 90 <0f> 0b 90 eb b0 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c d6 fb ff ff
RSP: 0018:ffffc90000126cc0 EFLAGS: 00010246
RAX: 000000000000001f RBX: ffff88803373c000 RCX: 355499c609706200
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffc90000126a47 R09: 1ffff92000024d48
R10: dffffc0000000000 R11: fffff52000024d49 R12: 0000000000000000
R13: ffff88803373c0d8 R14: ffff888037868400 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125536000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a26fdda5c0 CR3: 0000000061a08000 CR4: 00000000003526f0
Call Trace:
hfs_bmap_alloc+0x5c1/0x650 fs/hfs/btree.c:326
hfs_btree_inc_height+0x100/0xad0 fs/hfs/brec.c:490
hfs_brec_insert+0x7ef/0xc90 fs/hfs/brec.c:148
__hfs_ext_write_extent+0x2a1/0x470 fs/hfs/extent.c:124
hfs_ext_write_extent+0x17e/0x210 fs/hfs/extent.c:144
hfs_write_inode+0x117/0x960 fs/hfs/inode.c:459
write_inode fs/fs-writeback.c:1582 [inline]
__writeback_single_inode+0x75a/0x11a0 fs/fs-writeback.c:1813
writeback_sb_inodes+0x992/0x1a20 fs/fs-writeback.c:2042
wb_writeback+0x456/0xb70 fs/fs-writeback.c:2227
wb_do_writeback fs/fs-writeback.c:2374 [inline]
wb_workfn+0x414/0xf50 fs/fs-writeback.c:2414
process_one_work+0x9ab/0x1780 kernel/workqueue.c:3288
process_scheduled_works kernel/workqueue.c:3379 [inline]
worker_thread+0xba8/0x11e0 kernel/workqueue.c:3465
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245