====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.2.187/6863 is trying to acquire lock: ffff88807bd520f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0xa7/0xc40 fs/hfsplus/bitmap.c:35 but task is already holding lock: ffff88807d79b048 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1f8/0x1ba0 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}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 hfsplus_get_block+0x398/0x15d0 fs/hfsplus/extents.c:260 block_read_full_folio+0x29f/0x830 fs/buffer.c:2420 filemap_read_folio+0x117/0x380 mm/filemap.c:2444 do_read_cache_folio+0x350/0x590 mm/filemap.c:4024 do_read_cache_page mm/filemap.c:4090 [inline] read_cache_page+0x5d/0x170 mm/filemap.c:4099 read_mapping_page include/linux/pagemap.h:993 [inline] hfsplus_block_allocate+0xf3/0xc40 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0xa9a/0x1ba0 fs/hfsplus/extents.c:464 hfsplus_get_block+0x40a/0x15d0 fs/hfsplus/extents.c:245 __block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145 block_write_begin fs/buffer.c:2256 [inline] cont_write_begin+0x789/0xb50 fs/buffer.c:2594 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 generic_perform_write+0x2c5/0x900 mm/filemap.c:4242 generic_file_write_iter+0x117/0x550 mm/filemap.c:4385 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 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+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 hfsplus_block_allocate+0xa7/0xc40 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xa9a/0x1ba0 fs/hfsplus/extents.c:464 hfsplus_bmap_reserve+0x122/0x500 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x18e/0x1120 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0x12f5/0x1b50 fs/hfsplus/super.c:580 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691 vfs_get_tree+0x92/0x2b0 fs/super.c:1751 fc_mount fs/namespace.c:1208 [inline] do_new_mount_fc fs/namespace.c:3651 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3727 do_mount fs/namespace.c:4050 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4215 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 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 *** 4 locks held by syz.2.187/6863: #0: ffff88807a1740e0 (&type->s_umount_key#78/1){+.+.}-{4:4}, at: alloc_super+0x1bb/0x930 fs/super.c:344 #1: ffff88807bd52198 (&sbi->vh_mutex){+.+.}-{4:4}, at: hfsplus_fill_super+0x1278/0x1b50 fs/hfsplus/super.c:573 #2: ffff88807ac3c0b0 (&tree->tree_lock#2){+.+.}-{4:4}, at: hfsplus_find_init+0x168/0x290 fs/hfsplus/bfind.c:28 #3: ffff88807d79b048 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1f8/0x1ba0 fs/hfsplus/extents.c:453 stack backtrace: CPU: 0 UID: 0 PID: 6863 Comm: syz.2.187 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043 check_noncircular+0x134/0x160 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+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 hfsplus_block_allocate+0xa7/0xc40 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xa9a/0x1ba0 fs/hfsplus/extents.c:464 hfsplus_bmap_reserve+0x122/0x500 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x18e/0x1120 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0x12f5/0x1b50 fs/hfsplus/super.c:580 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691 vfs_get_tree+0x92/0x2b0 fs/super.c:1751 fc_mount fs/namespace.c:1208 [inline] do_new_mount_fc fs/namespace.c:3651 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3727 do_mount fs/namespace.c:4050 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4215 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9d7479066a Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f9d7566be68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f9d7566bef0 RCX: 00007f9d7479066a RDX: 0000200000000100 RSI: 0000200000002900 RDI: 00007f9d7566beb0 RBP: 0000200000000100 R08: 00007f9d7566bef0 R09: 0000000002000010 R10: 0000000002000010 R11: 0000000000000246 R12: 0000200000002900 R13: 00007f9d7566beb0 R14: 00000000000006e5 R15: 0000200000000c00