====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.912/10276 is trying to acquire lock: ffff888074551c08 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_get_block+0x3a1/0x15a0 fs/hfsplus/extents.c:260 but task is already holding lock: ffff8880245ee8f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x93/0x910 fs/hfsplus/bitmap.c:35 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sbi->alloc_mutex){+.+.}-{3:3}: __mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 hfsplus_block_allocate+0x93/0x910 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xb1f/0x1a50 fs/hfsplus/extents.c:466 hfsplus_bmap_reserve+0x11e/0x4f0 fs/hfsplus/btree.c:357 hfsplus_create_cat+0x1c7/0x10c0 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0x14b8/0x1e70 fs/hfsplus/super.c:579 mount_bdev+0x287/0x3c0 fs/super.c:1400 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3034 do_mount fs/namespace.c:3377 [inline] __do_sys_mount fs/namespace.c:3585 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 hfsplus_get_block+0x3a1/0x15a0 fs/hfsplus/extents.c:260 block_read_full_page+0x306/0xd40 fs/buffer.c:2290 do_read_cache_page+0x8a1/0x1030 mm/filemap.c:-1 read_mapping_page include/linux/pagemap.h:515 [inline] hfsplus_block_allocate+0xf1/0x910 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0xb1f/0x1a50 fs/hfsplus/extents.c:466 hfsplus_get_block+0x430/0x15a0 fs/hfsplus/extents.c:245 __block_write_begin_int+0x565/0x15d0 fs/buffer.c:2012 __block_write_begin fs/buffer.c:2062 [inline] block_write_begin fs/buffer.c:2122 [inline] cont_write_begin+0x598/0x7b0 fs/buffer.c:2471 hfsplus_write_begin+0x92/0xe0 fs/hfsplus/inode.c:53 __page_symlink+0x102/0x200 fs/namei.c:5199 hfsplus_symlink+0xc6/0x260 fs/hfsplus/dir.c:449 vfs_symlink+0x247/0x3d0 fs/namei.c:4437 do_symlinkat+0x1ab/0x6b0 fs/namei.c:4466 __do_sys_symlink fs/namei.c:4488 [inline] __se_sys_symlink fs/namei.c:4486 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4486 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sbi->alloc_mutex); lock(&HFSPLUS_I(inode)->extents_lock); lock(&sbi->alloc_mutex); lock(&HFSPLUS_I(inode)->extents_lock); *** DEADLOCK *** 5 locks held by syz.0.912/10276: #0: ffff888053eb2460 (sb_writers#29){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386 #1: ffff888074551740 (&type->i_mutex_dir_key#20/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline] #1: ffff888074551740 (&type->i_mutex_dir_key#20/1){+.+.}-{3:3}, at: filename_create+0x208/0x470 fs/namei.c:3843 #2: ffff8880245ee998 (&sbi->vh_mutex){+.+.}-{3:3}, at: hfsplus_symlink+0x7d/0x260 fs/hfsplus/dir.c:444 #3: ffff8880745558c8 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1cd/0x1a50 fs/hfsplus/extents.c:455 #4: ffff8880245ee8f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x93/0x910 fs/hfsplus/bitmap.c:35 stack backtrace: CPU: 0 PID: 10276 Comm: syz.0.912 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 hfsplus_get_block+0x3a1/0x15a0 fs/hfsplus/extents.c:260 block_read_full_page+0x306/0xd40 fs/buffer.c:2290 do_read_cache_page+0x8a1/0x1030 mm/filemap.c:-1 read_mapping_page include/linux/pagemap.h:515 [inline] hfsplus_block_allocate+0xf1/0x910 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0xb1f/0x1a50 fs/hfsplus/extents.c:466 hfsplus_get_block+0x430/0x15a0 fs/hfsplus/extents.c:245 __block_write_begin_int+0x565/0x15d0 fs/buffer.c:2012 __block_write_begin fs/buffer.c:2062 [inline] block_write_begin fs/buffer.c:2122 [inline] cont_write_begin+0x598/0x7b0 fs/buffer.c:2471 hfsplus_write_begin+0x92/0xe0 fs/hfsplus/inode.c:53 __page_symlink+0x102/0x200 fs/namei.c:5199 hfsplus_symlink+0xc6/0x260 fs/hfsplus/dir.c:449 vfs_symlink+0x247/0x3d0 fs/namei.c:4437 do_symlinkat+0x1ab/0x6b0 fs/namei.c:4466 __do_sys_symlink fs/namei.c:4488 [inline] __se_sys_symlink fs/namei.c:4486 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4486 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff37d8d2dd9 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:00007ff37bb2c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 00007ff37db4bfa0 RCX: 00007ff37d8d2dd9 RDX: 0000000000000000 RSI: 0000200000000580 RDI: 0000200000000680 RBP: 00007ff37d968d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff37db4c038 R14: 00007ff37db4bfa0 R15: 00007ffe4505b308 9pnet: Insufficient options for proto=fd