====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:4/59 is trying to acquire lock: ffff888025f18778 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xdb/0x1220 fs/hfs/extent.c:397 but task is already holding lock: ffff888024f6a0b0 (&tree->tree_lock/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/1){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x129/0xcc0 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+0x51c/0xbd0 fs/hfs/extent.c:366 block_read_full_folio+0x42e/0xf40 fs/buffer.c:2406 filemap_read_folio+0x167/0x760 mm/filemap.c:2420 do_read_cache_folio+0x470/0x7e0 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+0x4a9/0x790 fs/hfs/bnode.c:388 hfs_bnode_find+0x222/0xcc0 fs/hfs/bnode.c:433 hfs_brec_find+0x173/0x510 fs/hfs/bfind.c:135 hfs_brec_read+0x24/0x110 fs/hfs/bfind.c:174 hfs_cat_find_brec+0x15d/0x3f0 fs/hfs/catalog.c:194 hfs_fill_super+0xdd5/0x1320 fs/hfs/super.c:419 mount_bdev+0x22b/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+0x2da/0x3c0 fs/namespace.c:3912 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 -> #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+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x129/0xcc0 kernel/locking/mutex.c:747 hfs_extend_file+0xdb/0x1220 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+0x162/0x1e0 fs/hfs/extent.c:144 hfs_write_inode+0x92/0x7d0 fs/hfs/inode.c:434 write_inode fs/fs-writeback.c:1483 [inline] __writeback_single_inode+0x705/0xee0 fs/fs-writeback.c:1700 writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1926 wb_writeback+0x450/0xba0 fs/fs-writeback.c:2105 wb_do_writeback fs/fs-writeback.c:2252 [inline] wb_workfn+0x3ff/0xe20 fs/fs-writeback.c:2292 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 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/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/u4:4/59: #0: ffff88814124c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff88814124c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900015a7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900015a7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff888024f6a0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x17e/0x1f0 fs/hfs/bfind.c:-1 stack backtrace: CPU: 0 PID: 59 Comm: kworker/u4:4 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: writeback wb_workfn (flush-7:2) Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 check_noncircular+0x2bd/0x3c0 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+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x129/0xcc0 kernel/locking/mutex.c:747 hfs_extend_file+0xdb/0x1220 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+0x162/0x1e0 fs/hfs/extent.c:144 hfs_write_inode+0x92/0x7d0 fs/hfs/inode.c:434 write_inode fs/fs-writeback.c:1483 [inline] __writeback_single_inode+0x705/0xee0 fs/fs-writeback.c:1700 writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1926 wb_writeback+0x450/0xba0 fs/fs-writeback.c:2105 wb_do_writeback fs/fs-writeback.c:2252 [inline] wb_workfn+0x3ff/0xe20 fs/fs-writeback.c:2292 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 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: 1 PID: 59 at fs/hfs/bnode.c:520 hfs_bnode_create+0x3b9/0x440 fs/hfs/bnode.c:519 Modules linked in: CPU: 1 PID: 59 Comm: kworker/u4:4 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: writeback wb_workfn (flush-7:2) RIP: 0010:hfs_bnode_create+0x3b9/0x440 fs/hfs/bnode.c:520 Code: c3 c0 8a 89 ee e8 57 b3 0d 08 e9 73 fd ff ff e8 ad 78 2f ff 4c 89 ef e8 25 af 22 08 48 c7 c7 80 c3 c0 8a 89 ee e8 37 b3 0d 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:ffffc900015a6e18 EFLAGS: 00010246 RAX: 000000000000001f RBX: ffff888024f6a000 RCX: d7dfbf5991ed0500 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffc900015a6b27 R09: 1ffff920002b4d64 R10: dffffc0000000000 R11: fffff520002b4d65 R12: 0000000000000000 R13: ffff888024f6a0e0 R14: ffff888143763a00 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000000cb30000 CR4: 00000000003506e0 Call Trace: hfs_bmap_alloc+0x53b/0x5c0 fs/hfs/btree.c:326 hfs_btree_inc_height+0xf7/0xac0 fs/hfs/brec.c:490 hfs_brec_insert+0x742/0xbd0 fs/hfs/brec.c:148 __hfs_ext_write_extent+0x2a1/0x470 fs/hfs/extent.c:124 hfs_ext_write_extent+0x162/0x1e0 fs/hfs/extent.c:144 hfs_write_inode+0x92/0x7d0 fs/hfs/inode.c:434 write_inode fs/fs-writeback.c:1483 [inline] __writeback_single_inode+0x705/0xee0 fs/fs-writeback.c:1700 writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1926 wb_writeback+0x450/0xba0 fs/fs-writeback.c:2105 wb_do_writeback fs/fs-writeback.c:2252 [inline] wb_workfn+0x3ff/0xe20 fs/fs-writeback.c:2292 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 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