hfs: continuing without an alternate MDB ============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.7.317/8060 is trying to acquire lock: ffff8880281ca0a0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1 but task is already holding lock[ 331.686145][ T8060] but task is already holding lock: ffff8880281ca0a0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&tree->tree_lock#2/1); lock(&tree->tree_lock#2/1); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by syz.7.317/8060: #0: ffff888037b4a480 (sb_writers#21){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline] #0: ffff888037b4a480 (sb_writers#21){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff88806433e880 (&sb->s_type->i_mutex_key#29){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #1: ffff88806433e880 (&sb->s_type->i_mutex_key#29){+.+.}-{4:4}, at: generic_file_write_iter+0xec/0x550 mm/filemap.c:4454 #2: ffff88806433e6a8 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x1540 fs/hfs/extent.c:397 #3: ffff8880281ca0a0 (&tree->tree_lock#2/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1 #4: ffff88806433d0e8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x1540 fs/hfs/extent.c:397 stack backtrace: CPU: 1 UID: 0 PID: 8060 Comm: syz.7.317 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x2540/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552 hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_extend_file+0x2f6/0x1540 fs/hfs/extent.c:401 hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269 __hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x6b/0x9b0 fs/hfs/extent.c:174 hfs_ext_read_extent fs/hfs/extent.c:202 [inline] hfs_extend_file+0x31e/0x1540 fs/hfs/extent.c:401 hfs_get_block+0x3d7/0xbd0 fs/hfs/extent.c:353 __block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145 block_write_begin fs/buffer.c:2256 [inline] cont_write_begin+0x78c/0xb50 fs/buffer.c:2594 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53 cont_expand_zero fs/buffer.c:2522 [inline] cont_write_begin+0x2fd/0xb50 fs/buffer.c:2584 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53 generic_perform_write+0x29d/0x8c0 mm/filemap.c:4314 generic_file_write_iter+0x118/0x550 mm/filemap.c:4457 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5d5/0xb40 fs/read_write.c:686 ksys_pwrite64 fs/read_write.c:793 [inline] __do_sys_pwrite64 fs/read_write.c:801 [inline] __se_sys_pwrite64 fs/read_write.c:798 [inline] __x64_sys_pwrite64+0x196/0x220 fs/read_write.c:798 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9eaa2df749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9ea8546038 EFLAGS: 00000246 ORIG_RAX: 0000000000000012 RAX: ffffffffffffffda RBX: 00007f9eaa535fa0 RCX: 00007f9eaa2df749 RDX: 0000000000000001 RSI: 0000200000000140 RDI: 0000000000000005 RBP: 00007f9eaa363f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000008080c61 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9eaa536038 R14: 00007f9eaa535fa0 R15: 00007ffca03f8e98 ------------[ cut here ]------------ rtmutex deadlock detected WARNING: kernel/locking/rtmutex.c:1674 at rt_mutex_handle_deadlock+0x21/0xb0 kernel/locking/rtmutex.c:1674, CPU#1: syz.7.317/8060 Modules linked in: CPU: 1 UID: 0 PID: 8060 Comm: syz.7.317 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:rt_mutex_handle_deadlock+0x21/0xb0 kernel/locking/rtmutex.c:1674 Code: 90 90 90 90 90 90 90 90 90 41 57 41 56 41 55 41 54 53 83 ff dd 0f 85 86 00 00 00 48 89 f7 e8 a6 39 01 00 48 8d 3d 8f 7f 0a 04 <67> 48 0f b9 3a 4c 8d 3d 00 00 00 00 65 48 8b 1c 25 08 10 b3 91 4c RSP: 0018:ffffc90004fdec10 EFLAGS: 00010286 RAX: 0000000080000000 RBX: ffffc90004fdeca0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8b3f57c0 RDI: ffffffff8ede5a60 RBP: ffffc90004fdeda8 R08: ffffffff8edb3777 R09: 1ffffffff1db66ee R10: dffffc0000000000 R11: fffffbfff1db66ef R12: 1ffff920009fbd90 R13: ffffffff8ad3d5b9 R14: ffff8880281ca048 R15: dffffc0000000000 FS: 00007f9ea85466c0(0000) GS:ffff888126def000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c29c7fb CR3: 00000000337de000 CR4: 00000000003526f0 Call Trace: __rt_mutex_slowlock kernel/locking/rtmutex.c:1734 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline] rt_mutex_slowlock+0x666/0x6b0 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline] mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:552 hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_extend_file+0x2f6/0x1540 fs/hfs/extent.c:401 hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269 __hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x6b/0x9b0 fs/hfs/extent.c:174 hfs_ext_read_extent fs/hfs/extent.c:202 [inline] hfs_extend_file+0x31e/0x1540 fs/hfs/extent.c:401 hfs_get_block+0x3d7/0xbd0 fs/hfs/extent.c:353 __block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145 block_write_begin fs/buffer.c:2256 [inline] cont_write_begin+0x78c/0xb50 fs/buffer.c:2594 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53 cont_expand_zero fs/buffer.c:2522 [inline] cont_write_begin+0x2fd/0xb50 fs/buffer.c:2584 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53 generic_perform_write+0x29d/0x8c0 mm/filemap.c:4314 generic_file_write_iter+0x118/0x550 mm/filemap.c:4457 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5d5/0xb40 fs/read_write.c:686 ksys_pwrite64 fs/read_write.c:793 [inline] __do_sys_pwrite64 fs/read_write.c:801 [inline] __se_sys_pwrite64 fs/read_write.c:798 [inline] __x64_sys_pwrite64+0x196/0x220 fs/read_write.c:798 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9eaa2df749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9ea8546038 EFLAGS: 00000246 ORIG_RAX: 0000000000000012 RAX: ffffffffffffffda RBX: 00007f9eaa535fa0 RCX: 00007f9eaa2df749 RDX: 0000000000000001 RSI: 0000200000000140 RDI: 0000000000000005 RBP: 00007f9eaa363f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000008080c61 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9eaa536038 R14: 00007f9eaa535fa0 R15: 00007ffca03f8e98 ---------------- 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 86 00 00 00 jne 0xa1 1b: 48 89 f7 mov %rsi,%rdi 1e: e8 a6 39 01 00 call 0x139c9 23: 48 8d 3d 8f 7f 0a 04 lea 0x40a7f8f(%rip),%rdi # 0x40a7fb9 * 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 1c 25 08 10 mov %gs:0xffffffff91b31008,%rbx 3d: b3 91 3f: 4c rex.WR