======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
kworker/u4:1/12 is trying to acquire lock:
ffff8880778634f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xff/0x1380 fs/hfs/extent.c:397
but task is already holding lock:
ffff888064df80b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfs_find_init+0x17e/0x1f0 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#2/1){+.+.}-{3:3}:
__mutex_lock_common kernel/locking/mutex.c:603 [inline]
__mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747
hfs_find_init+0x17e/0x1f0 fs/hfs/bfind.c:-1
hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
hfs_get_block+0x557/0xc50 fs/hfs/extent.c:366
block_read_full_folio+0x44b/0xf60 fs/buffer.c:2406
filemap_read_folio+0x172/0x760 mm/filemap.c:2420
do_read_cache_folio+0x468/0x7d0 mm/filemap.c:3804
do_read_cache_page+0x32/0x250 mm/filemap.c:3870
read_mapping_page include/linux/pagemap.h:892 [inline]
__hfs_bnode_create+0x4b1/0x7b0 fs/hfs/bnode.c:388
hfs_bnode_find+0x222/0xd40 fs/hfs/bnode.c:433
hfs_brec_find+0x17c/0x500 fs/hfs/bfind.c:135
hfs_brec_read+0x24/0x110 fs/hfs/bfind.c:174
hfs_cat_find_brec+0x178/0x3f0 fs/hfs/catalog.c:194
hfs_fill_super+0xee2/0x14a0 fs/hfs/super.c:419
mount_bdev+0x221/0x2d0 fs/super.c:1643
legacy_get_tree+0xea/0x180 fs/fs_context.c:662
vfs_get_tree+0x8c/0x280 fs/super.c:1764
do_new_mount+0x24b/0xa40 fs/namespace.c:3386
do_mount fs/namespace.c:3726 [inline]
__do_sys_mount fs/namespace.c:3935 [inline]
__se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
-> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2df1/0x7d40 kernel/locking/lockdep.c:5137
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
__mutex_lock_common kernel/locking/mutex.c:603 [inline]
__mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747
hfs_extend_file+0xff/0x1380 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+0x17f/0x210 fs/hfs/extent.c:144
hfs_write_inode+0xdc/0x880 fs/hfs/inode.c:434
write_inode fs/fs-writeback.c:1483 [inline]
__writeback_single_inode+0x705/0xec0 fs/fs-writeback.c:1700
writeback_sb_inodes+0x7cd/0xf50 fs/fs-writeback.c:1926
wb_writeback+0x46a/0xbf0 fs/fs-writeback.c:2105
wb_do_writeback fs/fs-writeback.c:2252 [inline]
wb_workfn+0x400/0xe60 fs/fs-writeback.c:2292
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&tree->tree_lock#2/1);
lock(&HFS_I(tree->inode)->extents_lock);
lock(&tree->tree_lock#2/1);
lock(&HFS_I(tree->inode)->extents_lock);
*** DEADLOCK ***
3 locks held by kworker/u4:1/12:
#0: ffff888142e6a138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888142e6a138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc90000117d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90000117d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#2: ffff888064df80b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfs_find_init+0x17e/0x1f0 fs/hfs/bfind.c:-1
stack backtrace:
CPU: 0 PID: 12 Comm: kworker/u4:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: writeback wb_workfn (flush-7:5)
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2187
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2df1/0x7d40 kernel/locking/lockdep.c:5137
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
__mutex_lock_common kernel/locking/mutex.c:603 [inline]
__mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747
hfs_extend_file+0xff/0x1380 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+0x17f/0x210 fs/hfs/extent.c:144
hfs_write_inode+0xdc/0x880 fs/hfs/inode.c:434
write_inode fs/fs-writeback.c:1483 [inline]
__writeback_single_inode+0x705/0xec0 fs/fs-writeback.c:1700
writeback_sb_inodes+0x7cd/0xf50 fs/fs-writeback.c:1926
wb_writeback+0x46a/0xbf0 fs/fs-writeback.c:2105
wb_do_writeback fs/fs-writeback.c:2252 [inline]
wb_workfn+0x400/0xe60 fs/fs-writeback.c:2292
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
hfs: new node 0 already hashed?
------------[ cut here ]------------
WARNING: CPU: 0 PID: 12 at fs/hfs/bnode.c:520 hfs_bnode_create+0x3b9/0x440 fs/hfs/bnode.c:519
Modules linked in:
CPU: 0 PID: 12 Comm: kworker/u4:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: writeback wb_workfn (flush-7:5)
RIP: 0010:hfs_bnode_create+0x3b9/0x440 fs/hfs/bnode.c:520
Code: d4 e0 8a 89 ee e8 47 8c 1f 08 e9 73 fd ff ff e8 1d 1c 2d ff 4c 89 ef e8 45 bc 34 08 48 c7 c7 c0 d4 e0 8a 89 ee e8 27 8c 1f 08 <0f> 0b eb b7 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 7f fc ff ff 4c
RSP: 0018:ffffc90000116e18 EFLAGS: 00010246
RAX: 000000000000001f RBX: ffff888064df8000 RCX: 9b435f1b1eac2d00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffc90000116a27 R09: 1ffff92000022d44
R10: dffffc0000000000 R11: fffff52000022d45 R12: 0000000000000000
R13: ffff888064df80e0 R14: ffff88804ecf8800 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31021ff8 CR3: 000000002f6b3000 CR4: 00000000003506f0
Call Trace:
hfs_bmap_alloc+0x541/0x5d0 fs/hfs/btree.c:326
hfs_btree_inc_height+0x101/0xac0 fs/hfs/brec.c:490
hfs_brec_insert+0x748/0xbd0 fs/hfs/brec.c:148
__hfs_ext_write_extent+0x2a1/0x470 fs/hfs/extent.c:124
hfs_ext_write_extent+0x17f/0x210 fs/hfs/extent.c:144
hfs_write_inode+0xdc/0x880 fs/hfs/inode.c:434
write_inode fs/fs-writeback.c:1483 [inline]
__writeback_single_inode+0x705/0xec0 fs/fs-writeback.c:1700
writeback_sb_inodes+0x7cd/0xf50 fs/fs-writeback.c:1926
wb_writeback+0x46a/0xbf0 fs/fs-writeback.c:2105
wb_do_writeback fs/fs-writeback.c:2252 [inline]
wb_workfn+0x400/0xe60 fs/fs-writeback.c:2292
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293