====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.3.1355/21154 is trying to acquire lock: ffff888060bddb98 (&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: ffff8880344a00a0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1 which lock alrea[ 1571.923371][T21154] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&tree->tree_lock/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+0x35f/0x1680 fs/hfs/extent.c:401 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:269 hfs_cat_create+0x221/0x810 fs/hfs/catalog.c:104 hfs_mkdir+0x79/0xe0 fs/hfs/dir.c:226 vfs_mkdir+0x402/0x620 fs/namei.c:5276 filename_mkdirat+0x289/0x520 fs/namei.c:5309 __do_sys_mkdirat fs/namei.c:5330 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5327 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1520/0x2ce0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __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:269 __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+0x3a0/0x1680 fs/hfs/extent.c:401 hfs_get_block+0x401/0xbe0 fs/hfs/extent.c:353 __block_write_begin_int+0x6c2/0x1900 fs/buffer.c:2123 block_write_begin fs/buffer.c:2234 [inline] cont_write_begin+0x71b/0xac0 fs/buffer.c:2596 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:54 cont_expand_zero fs/buffer.c:2524 [inline] cont_write_begin+0x2d6/0xac0 fs/buffer.c:2586 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:54 hfs_file_truncate+0x1cf/0xb60 fs/hfs/extent.c:495 hfs_inode_setattr+0x49a/0x6c0 fs/hfs/inode.c:669 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:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 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/1); lock(&HFS_I(tree->inode)->extents_lock); lock(&tree->tree_lock/1); lock(&HFS_I(tree->inode)->extents_lock); *** DEADLOCK *** 4 locks held by syz.3.1355/21154: #0: ffff88803f94e500 (sb_writers#14){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494 #1: ffff888060bd8f70 (&sb->s_type->i_mutex_key#26){++++}-{4:4}, at: inode_lock_killable include/linux/fs.h:1029 [inline] #1: ffff888060bd8f70 (&sb->s_type->i_mutex_key#26){++++}-{4:4}, at: do_truncate+0x18f/0x250 fs/open.c:63 #2: ffff888060bd8d98 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:397 #3: ffff8880344a00a0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1 stack backtrace: CPU: 1 UID: 0 PID: 21154 Comm: syz.3.1355 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1520/0x2ce0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __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:269 __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+0x3a0/0x1680 fs/hfs/extent.c:401 hfs_get_block+0x401/0xbe0 fs/hfs/extent.c:353 __block_write_begin_int+0x6c2/0x1900 fs/buffer.c:2123 block_write_begin fs/buffer.c:2234 [inline] cont_write_begin+0x71b/0xac0 fs/buffer.c:2596 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:54 cont_expand_zero fs/buffer.c:2524 [inline] cont_write_begin+0x2d6/0xac0 fs/buffer.c:2586 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:54 hfs_file_truncate+0x1cf/0xb60 fs/hfs/extent.c:495 hfs_inode_setattr+0x49a/0x6c0 fs/hfs/inode.c:669 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:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2dfc8ede59 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:00007f2dfab46028 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007f2dfcb75fa0 RCX: 00007f2dfc8ede59 RDX: 0000000000000000 RSI: 0000000003000000 RDI: 0000200000000900 RBP: 00007f2dfc983e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2dfcb76038 R14: 00007f2dfcb75fa0 R15: 00007fffed17d168 ------------[ cut here ]------------ rtmutex deadlock detected WARNING: kernel/locking/rtmutex.c:1698 at rt_mutex_handle_deadlock+0x21/0xb0 kernel/locking/rtmutex.c:1698, CPU#1: syz.3.1355/21154 Modules linked in: CPU: 1 UID: 0 PID: 21154 Comm: syz.3.1355 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 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 40 01 00 48 8d 3d 0f 8f 6e 04 <67> 48 0f b9 3a 4c 8d 3d 00 00 00 00 65 48 8b 1d 43 0d 59 07 4c 8d RSP: 0018:ffffc9000402ec50 EFLAGS: 00010286 RAX: 0000000080000000 RBX: 00000000ffffffdd RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8bca6360 RDI: ffffffff8fb2f1c0 RBP: ffffc9000402ede8 R08: ffffffff8faf86f7 R09: 1ffffffff1f5f0de R10: dffffc0000000000 R11: fffffbfff1f5f0df R12: 1ffff92000805d98 R13: ffffffff8b445cf2 R14: ffff8880344a0048 R15: dffffc0000000000 FS: 00007f2dfab466c0(0000) GS:ffff888125d49000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f69fc107e20 CR3: 00000000288ce000 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+0x73c/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+0x35f/0x1680 fs/hfs/extent.c:401 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:269 __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+0x3a0/0x1680 fs/hfs/extent.c:401 hfs_get_block+0x401/0xbe0 fs/hfs/extent.c:353 __block_write_begin_int+0x6c2/0x1900 fs/buffer.c:2123 block_write_begin fs/buffer.c:2234 [inline] cont_write_begin+0x71b/0xac0 fs/buffer.c:2596 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:54 cont_expand_zero fs/buffer.c:2524 [inline] cont_write_begin+0x2d6/0xac0 fs/buffer.c:2586 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:54 hfs_file_truncate+0x1cf/0xb60 fs/hfs/extent.c:495 hfs_inode_setattr+0x49a/0x6c0 fs/hfs/inode.c:669 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:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2dfc8ede59 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:00007f2dfab46028 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007f2dfcb75fa0 RCX: 00007f2dfc8ede59 RDX: 0000000000000000 RSI: 0000000003000000 RDI: 0000200000000900 RBP: 00007f2dfc983e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2dfcb76038 R14: 00007f2dfcb75fa0 R15: 00007fffed17d168 ---------------- 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 40 01 00 call 0x14039 23: 48 8d 3d 0f 8f 6e 04 lea 0x46e8f0f(%rip),%rdi # 0x46e8f39 * 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 43 0d 59 mov %gs:0x7590d43(%rip),%rbx # 0x7590d81 3d: 07 3e: 4c rex.WR 3f: 8d .byte 0x8d