============================================ WARNING: possible recursive locking detected 6.1.25-syzkaller #0 Not tainted -------------------------------------------- kworker/u4:20/9374 is trying to acquire lock: ffff00014b8b40b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8 but task is already holding lock: ffff00014b8b40b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&tree->tree_lock/1); lock(&tree->tree_lock/1); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by kworker/u4:20/9374: #0: ffff0000c0e3d938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2262 #1: ffff800020617c20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2264 #2: ffff00014b8b40b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8 #3: ffff0000c2cabb78 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xe4/0x1130 fs/hfs/extent.c:397 stack backtrace: CPU: 1 PID: 9374 Comm: kworker/u4:20 Not tainted 6.1.25-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 Workqueue: writeback wb_workfn (flush-7:1) Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 __lock_acquire+0x6310/0x764c kernel/locking/lockdep.c:5056 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5669 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 hfs_find_init+0x148/0x1c8 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_extend_file+0x270/0x1130 fs/hfs/extent.c:401 hfs_bmap_reserve+0xd0/0x3b4 fs/hfs/btree.c:234 __hfs_ext_write_extent+0x1a0/0x468 fs/hfs/extent.c:121 hfs_ext_write_extent+0x148/0x1c0 fs/hfs/extent.c:144 hfs_write_inode+0xc0/0xc1c fs/hfs/inode.c:431 write_inode fs/fs-writeback.c:1440 [inline] __writeback_single_inode+0x614/0x1770 fs/fs-writeback.c:1652 writeback_sb_inodes+0x978/0x16c0 fs/fs-writeback.c:1878 wb_writeback+0x414/0x1130 fs/fs-writeback.c:2052 wb_do_writeback fs/fs-writeback.c:2195 [inline] wb_workfn+0x3a8/0x1034 fs/fs-writeback.c:2235 process_one_work+0x7ac/0x1404 kernel/workqueue.c:2289 worker_thread+0x8e4/0xfec kernel/workqueue.c:2436 kthread+0x24c/0x2d4 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860