====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.3.466/9749 is trying to acquire lock: ffff88803534c818 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:397 but task is already holding lock: ffff888027ba60a0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x18d/0x300 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){+.+.}-{4:4}: __mutex_lock_common kernel/locking/rtmutex_api.c:559 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:578 hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_extend_file+0x367/0x1680 fs/hfs/extent.c:401 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:399 hfs_cat_create+0x23d/0x870 fs/hfs/catalog.c:104 hfs_mkdir+0x73/0xe0 fs/hfs/dir.c:226 vfs_mkdir+0x408/0x620 fs/namei.c:5410 filename_mkdirat+0x289/0x520 fs/namei.c:5443 __do_sys_mkdirat fs/namei.c:5464 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5461 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3181 [inline] check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x15ff/0x2e40 kernel/locking/lockdep.c:5254 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908 __mutex_lock_common kernel/locking/rtmutex_api.c:559 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:578 hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:397 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:399 __hfs_ext_write_extent+0x1fc/0x470 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x6e/0x9b0 fs/hfs/extent.c:174 hfs_ext_read_extent fs/hfs/extent.c:202 [inline] hfs_extend_file+0x3ad/0x1680 fs/hfs/extent.c:401 hfs_get_block+0x401/0xbf0 fs/hfs/extent.c:353 __block_write_begin_int+0x6c2/0x1900 fs/buffer.c:2030 block_write_begin fs/buffer.c:2144 [inline] cont_write_begin+0x71b/0xac0 fs/buffer.c:2506 hfs_write_begin+0x123/0x1c0 fs/hfs/inode.c:62 cont_expand_zero fs/buffer.c:2434 [inline] cont_write_begin+0x2d6/0xac0 fs/buffer.c:2496 hfs_write_begin+0x123/0x1c0 fs/hfs/inode.c:62 hfs_file_truncate+0x1d2/0xb70 fs/hfs/extent.c:495 hfs_inode_setattr+0x4a3/0x6d0 fs/hfs/inode.c:688 notify_change+0xbb8/0xec0 fs/attr.c:556 do_truncate+0x1c2/0x250 fs/open.c:68 vfs_truncate+0x4b7/0x540 fs/open.c:118 ksys_truncate+0xf3/0x1c0 fs/open.c:142 __do_sys_truncate fs/open.c:154 [inline] __se_sys_truncate fs/open.c:152 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:152 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f 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 *** locks held by syz.3.466/9749: 4, last CPU#0: #0: ffff888033f70510 (sb_writers#23){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494 #1: ffff88803534b670 (&sb->s_type->i_mutex_key#50){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:1029 [inline] #1: ffff88803534b670 (&sb->s_type->i_mutex_key#50){+.+.}-{4:4}, at: do_truncate+0x18f/0x250 fs/open.c:63 #2: ffff88803534b498 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:397 #3: ffff888027ba60a0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1 stack backtrace: CPU: 0 UID: 0 PID: 9749 Comm: syz.3.466 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2059 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2191 check_prev_add kernel/locking/lockdep.c:3181 [inline] check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x15ff/0x2e40 kernel/locking/lockdep.c:5254 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908 __mutex_lock_common kernel/locking/rtmutex_api.c:559 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:578 hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:397 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:399 __hfs_ext_write_extent+0x1fc/0x470 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x6e/0x9b0 fs/hfs/extent.c:174 hfs_ext_read_extent fs/hfs/extent.c:202 [inline] hfs_extend_file+0x3ad/0x1680 fs/hfs/extent.c:401 hfs_get_block+0x401/0xbf0 fs/hfs/extent.c:353 __block_write_begin_int+0x6c2/0x1900 fs/buffer.c:2030 block_write_begin fs/buffer.c:2144 [inline] cont_write_begin+0x71b/0xac0 fs/buffer.c:2506 hfs_write_begin+0x123/0x1c0 fs/hfs/inode.c:62 cont_expand_zero fs/buffer.c:2434 [inline] cont_write_begin+0x2d6/0xac0 fs/buffer.c:2496 hfs_write_begin+0x123/0x1c0 fs/hfs/inode.c:62 hfs_file_truncate+0x1d2/0xb70 fs/hfs/extent.c:495 hfs_inode_setattr+0x4a3/0x6d0 fs/hfs/inode.c:688 notify_change+0xbb8/0xec0 fs/attr.c:556 do_truncate+0x1c2/0x250 fs/open.c:68 vfs_truncate+0x4b7/0x540 fs/open.c:118 ksys_truncate+0xf3/0x1c0 fs/open.c:142 __do_sys_truncate fs/open.c:154 [inline] __se_sys_truncate fs/open.c:152 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:152 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f241a37e159 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f24185d6028 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007f241a605fa0 RCX: 00007f241a37e159 RDX: 0000000000000000 RSI: 0000000001000707 RDI: 0000200000000340 RBP: 00007f241a415024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f241a606038 R14: 00007f241a605fa0 R15: 00007ffc6c50ae98 ------------[ cut here ]------------ rtmutex deadlock detected WARNING: kernel/locking/rtmutex.c:1698 at rt_mutex_handle_deadlock+0x21/0xb0 kernel/locking/rtmutex.c:1698, CPU#0: syz.3.466/9749 Modules linked in: CPU: 0 UID: 0 PID: 9749 Comm: syz.3.466 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:rt_mutex_handle_deadlock+0x21/0xb0 kernel/locking/rtmutex.c:1698 Code: 90 90 90 90 90 90 90 90 90 41 57 41 56 41 55 41 54 53 83 ff dd 0f 85 81 00 00 00 48 89 f7 e8 16 41 01 00 48 8d 3d ff 57 5d 04 <67> 48 0f b9 3a 4c 8d 3d 00 00 00 00 65 48 8b 1d f3 05 4d 07 4c 8d RSP: 0018:ffffc9000123ebd0 EFLAGS: 00010286 RAX: 8000000000000000 RBX: 00000000ffffffdd RCX: ffffffff99ade501 RDX: 0000000000000001 RSI: ffffffff8bcc2060 RDI: ffffffff8fb4f200 RBP: ffffc9000123ed68 R08: ffffffff8fb1db7f R09: 1ffffffff1f63b6f R10: dffffc0000000000 R11: fffffbfff1f63b70 R12: 1ffff92000247d88 R13: ffffffff8b579442 R14: ffff888027ba6048 R15: dffffc0000000000 FS: 00007f24185d66c0(0000) GS:ffff888125bd6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c33cff6 CR3: 00000000568cc000 CR4: 00000000003526f0 Call Trace: __rt_mutex_slowlock kernel/locking/rtmutex.c:1760 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1787 [inline] rt_mutex_slowlock+0x73e/0x780 kernel/locking/rtmutex.c:1827 __rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578 hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_extend_file+0x367/0x1680 fs/hfs/extent.c:401 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:399 __hfs_ext_write_extent+0x1fc/0x470 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x6e/0x9b0 fs/hfs/extent.c:174 hfs_ext_read_extent fs/hfs/extent.c:202 [inline] hfs_extend_file+0x3ad/0x1680 fs/hfs/extent.c:401 hfs_get_block+0x401/0xbf0 fs/hfs/extent.c:353 __block_write_begin_int+0x6c2/0x1900 fs/buffer.c:2030 block_write_begin fs/buffer.c:2144 [inline] cont_write_begin+0x71b/0xac0 fs/buffer.c:2506 hfs_write_begin+0x123/0x1c0 fs/hfs/inode.c:62 cont_expand_zero fs/buffer.c:2434 [inline] cont_write_begin+0x2d6/0xac0 fs/buffer.c:2496 hfs_write_begin+0x123/0x1c0 fs/hfs/inode.c:62 hfs_file_truncate+0x1d2/0xb70 fs/hfs/extent.c:495 hfs_inode_setattr+0x4a3/0x6d0 fs/hfs/inode.c:688 notify_change+0xbb8/0xec0 fs/attr.c:556 do_truncate+0x1c2/0x250 fs/open.c:68 vfs_truncate+0x4b7/0x540 fs/open.c:118 ksys_truncate+0xf3/0x1c0 fs/open.c:142 __do_sys_truncate fs/open.c:154 [inline] __se_sys_truncate fs/open.c:152 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:152 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f241a37e159 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f24185d6028 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007f241a605fa0 RCX: 00007f241a37e159 RDX: 0000000000000000 RSI: 0000000001000707 RDI: 0000200000000340 RBP: 00007f241a415024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f241a606038 R14: 00007f241a605fa0 R15: 00007ffc6c50ae98 ---------------- Code disassembly (best guess): 0: 90 nop 1: 90 nop 2: 90 nop 3: 90 nop 4: 90 nop 5: 90 nop 6: 90 nop 7: 90 nop 8: 90 nop 9: 41 57 push %r15 b: 41 56 push %r14 d: 41 55 push %r13 f: 41 54 push %r12 11: 53 push %rbx 12: 83 ff dd cmp $0xffffffdd,%edi 15: 0f 85 81 00 00 00 jne 0x9c 1b: 48 89 f7 mov %rsi,%rdi 1e: e8 16 41 01 00 call 0x14139 23: 48 8d 3d ff 57 5d 04 lea 0x45d57ff(%rip),%rdi # 0x45d5829 * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: 4c 8d 3d 00 00 00 00 lea 0x0(%rip),%r15 # 0x36 36: 65 48 8b 1d f3 05 4d mov %gs:0x74d05f3(%rip),%rbx # 0x74d0631 3d: 07 3e: 4c rex.WR 3f: 8d .byte 0x8d