====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.5.45/6717 is trying to acquire lock: ffff888061ef80e8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0xa7/0xce0 fs/hfsplus/bitmap.c:35 but task is already holding lock: ffff888010be80f8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x215/0x1d70 fs/hfsplus/extents.c:453 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552 hfsplus_get_block+0x3a0/0x1670 fs/hfsplus/extents.c:260 block_read_full_folio+0x29f/0x830 fs/buffer.c:2420 filemap_read_folio+0x137/0x3b0 mm/filemap.c:2496 do_read_cache_folio+0x2bf/0x560 mm/filemap.c:4096 do_read_cache_page mm/filemap.c:4162 [inline] read_cache_page+0x5d/0x170 mm/filemap.c:4171 read_mapping_page include/linux/pagemap.h:1011 [inline] hfsplus_block_allocate+0xf3/0xce0 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0xb2d/0x1d70 fs/hfsplus/extents.c:464 hfsplus_get_block+0x42e/0x1670 fs/hfsplus/extents.c:245 __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2145 block_write_begin fs/buffer.c:2256 [inline] cont_write_begin+0x737/0xae0 fs/buffer.c:2594 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 cont_expand_zero fs/buffer.c:2522 [inline] cont_write_begin+0x2e7/0xae0 fs/buffer.c:2584 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 generic_cont_expand_simple+0x146/0x210 fs/buffer.c:2485 hfsplus_setattr+0x169/0x270 fs/hfsplus/inode.c:280 notify_change+0xc18/0xf60 fs/attr.c:546 do_truncate+0x1c2/0x250 fs/open.c:68 do_ftruncate+0x4e7/0x5c0 fs/open.c:195 do_sys_ftruncate fs/open.c:207 [inline] __do_sys_ftruncate fs/open.c:212 [inline] __se_sys_ftruncate fs/open.c:210 [inline] __x64_sys_ftruncate+0x92/0xf0 fs/open.c:210 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&sbi->alloc_mutex){+.+.}-{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+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x330 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 hfsplus_block_allocate+0xa7/0xce0 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xb2d/0x1d70 fs/hfsplus/extents.c:464 hfsplus_get_block+0x42e/0x1670 fs/hfsplus/extents.c:245 __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2145 block_write_begin fs/buffer.c:2256 [inline] cont_write_begin+0x737/0xae0 fs/buffer.c:2594 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 cont_expand_zero fs/buffer.c:2522 [inline] cont_write_begin+0x2e7/0xae0 fs/buffer.c:2584 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 generic_cont_expand_simple+0x146/0x210 fs/buffer.c:2485 hfsplus_setattr+0x169/0x270 fs/hfsplus/inode.c:280 notify_change+0xc18/0xf60 fs/attr.c:546 do_truncate+0x1c2/0x250 fs/open.c:68 vfs_truncate+0x4b4/0x540 fs/open.c:118 do_sys_truncate+0xf1/0x1c0 fs/open.c:141 __do_sys_truncate fs/open.c:153 [inline] __se_sys_truncate fs/open.c:151 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:151 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 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(&HFSPLUS_I(inode)->extents_lock); lock(&sbi->alloc_mutex); lock(&HFSPLUS_I(inode)->extents_lock); lock(&sbi->alloc_mutex); *** DEADLOCK *** 3 locks held by syz.5.45/6717: #0: ffff88805f72a480 (sb_writers#23){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff888010be8358 (&sb->s_type->i_mutex_key#33){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:1032 [inline] #1: ffff888010be8358 (&sb->s_type->i_mutex_key#33){+.+.}-{4:4}, at: do_truncate+0x18f/0x250 fs/open.c:63 #2: ffff888010be80f8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x215/0x1d70 fs/hfsplus/extents.c:453 stack backtrace: CPU: 0 UID: 0 PID: 6717 Comm: syz.5.45 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_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+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x330 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 hfsplus_block_allocate+0xa7/0xce0 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xb2d/0x1d70 fs/hfsplus/extents.c:464 hfsplus_get_block+0x42e/0x1670 fs/hfsplus/extents.c:245 __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2145 block_write_begin fs/buffer.c:2256 [inline] cont_write_begin+0x737/0xae0 fs/buffer.c:2594 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 cont_expand_zero fs/buffer.c:2522 [inline] cont_write_begin+0x2e7/0xae0 fs/buffer.c:2584 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 generic_cont_expand_simple+0x146/0x210 fs/buffer.c:2485 hfsplus_setattr+0x169/0x270 fs/hfsplus/inode.c:280 notify_change+0xc18/0xf60 fs/attr.c:546 do_truncate+0x1c2/0x250 fs/open.c:68 vfs_truncate+0x4b4/0x540 fs/open.c:118 do_sys_truncate+0xf1/0x1c0 fs/open.c:141 __do_sys_truncate fs/open.c:153 [inline] __se_sys_truncate fs/open.c:151 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:151 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f34fa16acb9 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:00007f34f83c6028 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007f34fa3e5fa0 RCX: 00007f34fa16acb9 RDX: 0000000000000000 RSI: 0000000000100003 RDI: 0000200000000000 RBP: 00007f34fa1d8bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f34fa3e6038 R14: 00007f34fa3e5fa0 R15: 00007fffdab563c8