====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:27/10521 is trying to acquire lock: ffff88807a3e34f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xfb/0x13f0 fs/hfs/extent.c:397 but task is already holding lock: ffff888030a080b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfs_find_init+0x15b/0x1d0 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+0x12d/0xaf0 kernel/locking/mutex.c:747 hfs_find_init+0x15b/0x1d0 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_extend_file+0x35d/0x13f0 fs/hfs/extent.c:401 hfs_bmap_reserve+0x103/0x420 fs/hfs/btree.c:234 hfs_cat_create+0x204/0x8e0 fs/hfs/catalog.c:104 hfs_create+0x62/0xd0 fs/hfs/dir.c:202 lookup_open fs/namei.c:3490 [inline] open_last_lookups fs/namei.c:3558 [inline] path_openat+0x1181/0x2ee0 fs/namei.c:3788 do_filp_open+0x1f1/0x430 fs/namei.c:3818 do_sys_openat2+0x150/0x4b0 fs/open.c:1320 do_sys_open fs/open.c:1336 [inline] __do_sys_openat fs/open.c:1352 [inline] __se_sys_openat fs/open.c:1347 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1347 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/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:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 hfs_extend_file+0xfb/0x13f0 fs/hfs/extent.c:397 hfs_bmap_reserve+0x103/0x420 fs/hfs/btree.c:234 __hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121 hfs_ext_write_extent+0x17b/0x200 fs/hfs/extent.c:144 hfs_write_inode+0xd8/0xa20 fs/hfs/inode.c:434 write_inode fs/fs-writeback.c:1470 [inline] __writeback_single_inode+0x75b/0x1160 fs/fs-writeback.c:1687 writeback_sb_inodes+0xb30/0x1850 fs/fs-writeback.c:1913 wb_writeback+0x482/0xd50 fs/fs-writeback.c:2087 wb_do_writeback fs/fs-writeback.c:2230 [inline] wb_workfn+0x423/0xee0 fs/fs-writeback.c:2270 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 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/u4:27/10521: #0: ffff888143291138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc9000d1a7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #2: ffff888030a080b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfs_find_init+0x15b/0x1d0 fs/hfs/bfind.c:-1 stack backtrace: CPU: 0 PID: 10521 Comm: kworker/u4:27 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 hfs_extend_file+0xfb/0x13f0 fs/hfs/extent.c:397 hfs_bmap_reserve+0x103/0x420 fs/hfs/btree.c:234 __hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121 hfs_ext_write_extent+0x17b/0x200 fs/hfs/extent.c:144 hfs_write_inode+0xd8/0xa20 fs/hfs/inode.c:434 write_inode fs/fs-writeback.c:1470 [inline] __writeback_single_inode+0x75b/0x1160 fs/fs-writeback.c:1687 writeback_sb_inodes+0xb30/0x1850 fs/fs-writeback.c:1913 wb_writeback+0x482/0xd50 fs/fs-writeback.c:2087 wb_do_writeback fs/fs-writeback.c:2230 [inline] wb_workfn+0x423/0xee0 fs/fs-writeback.c:2270 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 kworker/u4:27: attempt to access beyond end of device loop0: rw=2049, sector=76, nr_sectors = 1 limit=64 Buffer I/O error on dev loop0, logical block 76, lost async page write kworker/u4:27: attempt to access beyond end of device loop0: rw=2049, sector=77, nr_sectors = 1 limit=64 Buffer I/O error on dev loop0, logical block 77, lost async page write kworker/u4:27: attempt to access beyond end of device loop0: rw=2049, sector=78, nr_sectors = 1 limit=64 Buffer I/O error on dev loop0, logical block 78, lost async page write