loop0: detected capacity change from 0 to 1024 ====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc5-syzkaller-00038-g707df3375124 #0 Not tainted ------------------------------------------------------ syz.0.318/8804 is trying to acquire lock: ffff8880287770f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0x9d/0x8e0 fs/hfsplus/bitmap.c:35 but task is already holding lock: ffff88802fbec488 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1fc/0x1990 fs/hfsplus/extents.c:458 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:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746 hfsplus_get_block+0x39e/0x1530 fs/hfsplus/extents.c:260 block_read_full_folio+0x29c/0x830 fs/buffer.c:2427 filemap_read_folio+0x114/0x380 mm/filemap.c:2401 do_read_cache_folio+0x354/0x590 mm/filemap.c:3885 do_read_cache_page mm/filemap.c:3951 [inline] read_cache_page+0x5d/0x170 mm/filemap.c:3960 read_mapping_page include/linux/pagemap.h:989 [inline] hfsplus_block_allocate+0xff/0x8e0 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0xae3/0x1990 fs/hfsplus/extents.c:469 hfsplus_get_block+0x411/0x1530 fs/hfsplus/extents.c:245 __block_write_begin_int+0x6b2/0x1900 fs/buffer.c:2151 block_write_begin fs/buffer.c:2262 [inline] cont_write_begin+0x789/0xb50 fs/buffer.c:2601 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:46 page_symlink+0x240/0x3d0 fs/namei.c:5480 hfsplus_symlink+0xca/0x260 fs/hfsplus/dir.c:449 vfs_symlink+0x140/0x2f0 fs/namei.c:4723 do_symlinkat+0x1b1/0x3f0 fs/namei.c:4749 __do_sys_symlink fs/namei.c:4770 [inline] __se_sys_symlink fs/namei.c:4768 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4768 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 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:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3909 __lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746 hfsplus_block_allocate+0x9d/0x8e0 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xae3/0x1990 fs/hfsplus/extents.c:469 hfsplus_bmap_reserve+0x122/0x500 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x183/0x1000 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0x1314/0x1b70 fs/hfsplus/super.c:561 get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1636 vfs_get_tree+0x8f/0x2b0 fs/super.c:1759 do_new_mount+0x24a/0xa40 fs/namespace.c:3884 do_mount fs/namespace.c:4224 [inline] __do_sys_mount fs/namespace.c:4435 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4412 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 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.0.318/8804: #0: ffff88814770c0e0 (&type->s_umount_key#88/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970 fs/super.c:344 #1: ffff888028777198 (&sbi->vh_mutex){+.+.}-{4:4}, at: hfsplus_fill_super+0x1297/0x1b70 fs/hfsplus/super.c:554 #2: ffff88807ebfe0b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x15a/0x1d0 fs/hfsplus/bfind.c:28 #3: ffff88802fbec488 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1fc/0x1990 fs/hfsplus/extents.c:458 stack backtrace: CPU: 0 UID: 0 PID: 8804 Comm: syz.0.318 Not tainted 6.15.0-rc5-syzkaller-00038-g707df3375124 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2079 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2211 check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3909 __lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746 hfsplus_block_allocate+0x9d/0x8e0 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xae3/0x1990 fs/hfsplus/extents.c:469 hfsplus_bmap_reserve+0x122/0x500 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x183/0x1000 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0x1314/0x1b70 fs/hfsplus/super.c:561 get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1636 vfs_get_tree+0x8f/0x2b0 fs/super.c:1759 do_new_mount+0x24a/0xa40 fs/namespace.c:3884 do_mount fs/namespace.c:4224 [inline] __do_sys_mount fs/namespace.c:4435 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4412 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f423b79010a 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:00007f423c65be68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f423c65bef0 RCX: 00007f423b79010a RDX: 0000200000000000 RSI: 0000200000002380 RDI: 00007f423c65beb0 RBP: 0000200000000000 R08: 00007f423c65bef0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000002380 R13: 00007f423c65beb0 R14: 00000000000006fe R15: 0000200000001400