====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.3.78/4805 is trying to acquire lock: ffff0000f2f3a2c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x188/0x1324 fs/hfsplus/extents.c:455 but task is already holding lock: ffff0000cce240b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x148/0x1c0 fs/hfsplus/bfind.c:28 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+0x1a0/0x1f3c kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 hfsplus_find_init+0x148/0x1c0 fs/hfsplus/bfind.c:28 hfsplus_file_truncate+0x2d8/0x9a4 fs/hfsplus/extents.c:580 hfsplus_write_failed+0x88/0xa4 fs/hfsplus/inode.c:42 hfsplus_write_begin+0xe0/0xe4 fs/hfsplus/inode.c:56 cont_expand_zero fs/buffer.c:2383 [inline] cont_write_begin+0x290/0x820 fs/buffer.c:2446 hfsplus_write_begin+0x98/0xe4 fs/hfsplus/inode.c:52 generic_cont_expand_simple+0x130/0x208 fs/buffer.c:2347 hfsplus_setattr+0x14c/0x25c fs/hfsplus/inode.c:283 notify_change+0xb5c/0xe20 fs/attr.c:499 do_truncate+0x188/0x20c fs/open.c:65 vfs_truncate+0x23c/0x2b0 fs/open.c:111 do_sys_truncate+0xec/0x1b4 fs/open.c:134 __do_sys_truncate fs/open.c:146 [inline] __se_sys_truncate fs/open.c:144 [inline] __arm64_sys_truncate+0x5c/0x70 fs/open.c:144 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 -> #0 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3830 [inline] __lock_acquire+0x2808/0x6634 kernel/locking/lockdep.c:5063 lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5676 __mutex_lock_common+0x1a0/0x1f3c kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 hfsplus_file_extend+0x188/0x1324 fs/hfsplus/extents.c:455 hfsplus_bmap_reserve+0xd0/0x458 fs/hfsplus/btree.c:358 __hfsplus_ext_write_extent+0x1e4/0x4b0 fs/hfsplus/extents.c:104 __hfsplus_ext_cache_extent+0x84/0x924 fs/hfsplus/extents.c:186 hfsplus_file_truncate+0x3b0/0x9a4 fs/hfsplus/extents.c:597 hfsplus_file_release+0xe4/0x3a8 fs/hfsplus/inode.c:258 __fput+0x1b4/0x7b0 fs/file_table.c:320 ____fput+0x20/0x30 fs/file_table.c:348 task_work_run+0x1f4/0x280 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x20f8/0x2c84 arch/arm64/kernel/signal.c:1151 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&tree->tree_lock/1); lock(&HFSPLUS_I(inode)->extents_lock); lock(&tree->tree_lock/1); lock(&HFSPLUS_I(inode)->extents_lock); *** DEADLOCK *** 3 locks held by syz.3.78/4805: #0: ffff0000d60e0300 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #0: ffff0000d60e0300 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: hfsplus_file_release+0xdc/0x3a8 fs/hfsplus/inode.c:257 #1: ffff0000d60e0108 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x21c/0x9a4 fs/hfsplus/extents.c:574 #2: ffff0000cce240b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x148/0x1c0 fs/hfsplus/bfind.c:28 stack backtrace: CPU: 1 PID: 4805 Comm: syz.3.78 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2048 check_noncircular+0x264/0x2f8 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3830 [inline] __lock_acquire+0x2808/0x6634 kernel/locking/lockdep.c:5063 lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5676 __mutex_lock_common+0x1a0/0x1f3c kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 hfsplus_file_extend+0x188/0x1324 fs/hfsplus/extents.c:455 hfsplus_bmap_reserve+0xd0/0x458 fs/hfsplus/btree.c:358 __hfsplus_ext_write_extent+0x1e4/0x4b0 fs/hfsplus/extents.c:104 __hfsplus_ext_cache_extent+0x84/0x924 fs/hfsplus/extents.c:186 hfsplus_file_truncate+0x3b0/0x9a4 fs/hfsplus/extents.c:597 hfsplus_file_release+0xe4/0x3a8 fs/hfsplus/inode.c:258 __fput+0x1b4/0x7b0 fs/file_table.c:320 ____fput+0x20/0x30 fs/file_table.c:348 task_work_run+0x1f4/0x280 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x20f8/0x2c84 arch/arm64/kernel/signal.c:1151 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585