====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.5.216/7408 is trying to acquire lock: ffff888067ea28e8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0xa7/0xce0 fs/hfsplus/bitmap.c:35 but task is already holding lock: ffff8880643c8ff8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x21b/0x1dc0 fs/hfsplus/extents.c:455 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:534 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:553 hfsplus_get_block+0x3a0/0x1670 fs/hfsplus/extents.c:262 block_read_full_folio+0x29f/0x830 fs/buffer.c:2317 filemap_read_folio+0x137/0x3b0 mm/filemap.c:2502 do_read_cache_folio+0x2bf/0x560 mm/filemap.c:4107 do_read_cache_page mm/filemap.c:4173 [inline] read_cache_page+0x5d/0x170 mm/filemap.c:4182 read_mapping_page include/linux/pagemap.h:1011 [inline] hfsplus_block_allocate+0xf3/0xce0 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0xb21/0x1dc0 fs/hfsplus/extents.c:466 hfsplus_get_block+0x42e/0x1670 fs/hfsplus/extents.c:247 __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2042 block_write_begin fs/buffer.c:2153 [inline] cont_write_begin+0x737/0xae0 fs/buffer.c:2491 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 page_symlink+0x27a/0x440 fs/namei.c:6402 hfsplus_symlink+0xd3/0x3a0 fs/hfsplus/dir.c:484 vfs_symlink+0x195/0x340 fs/namei.c:5643 filename_symlinkat+0x1cd/0x420 fs/namei.c:5668 __do_sys_symlinkat fs/namei.c:5688 [inline] __se_sys_symlinkat+0x4e/0x2b0 fs/namei.c:5683 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 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+0x106/0x350 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:553 hfsplus_block_allocate+0xa7/0xce0 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xb21/0x1dc0 fs/hfsplus/extents.c:466 hfsplus_get_block+0x42e/0x1670 fs/hfsplus/extents.c:247 __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2042 block_write_begin fs/buffer.c:2153 [inline] cont_write_begin+0x737/0xae0 fs/buffer.c:2491 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 cont_expand_zero fs/buffer.c:2419 [inline] cont_write_begin+0x2e7/0xae0 fs/buffer.c:2481 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 generic_perform_write+0x2af/0x8b0 mm/filemap.c:4325 generic_file_write_iter+0x14b/0x690 mm/filemap.c:4468 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x629/0xba0 fs/read_write.c:688 ksys_pwrite64 fs/read_write.c:795 [inline] __do_sys_pwrite64 fs/read_write.c:803 [inline] __se_sys_pwrite64 fs/read_write.c:800 [inline] __x64_sys_pwrite64+0x19c/0x230 fs/read_write.c:800 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 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.5.216/7408: #0: ffff888042ed8480 (sb_writers#32){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2724 [inline] #0: ffff888042ed8480 (sb_writers#32){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff8880643c9258 (&sb->s_type->i_mutex_key#48){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #1: ffff8880643c9258 (&sb->s_type->i_mutex_key#48){+.+.}-{4:4}, at: generic_file_write_iter+0x11f/0x690 mm/filemap.c:4465 #2: ffff8880643c8ff8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x21b/0x1dc0 fs/hfsplus/extents.c:455 stack backtrace: CPU: 0 UID: 0 PID: 7408 Comm: syz.5.216 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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+0x106/0x350 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:553 hfsplus_block_allocate+0xa7/0xce0 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xb21/0x1dc0 fs/hfsplus/extents.c:466 hfsplus_get_block+0x42e/0x1670 fs/hfsplus/extents.c:247 __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2042 block_write_begin fs/buffer.c:2153 [inline] cont_write_begin+0x737/0xae0 fs/buffer.c:2491 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 cont_expand_zero fs/buffer.c:2419 [inline] cont_write_begin+0x2e7/0xae0 fs/buffer.c:2481 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 generic_perform_write+0x2af/0x8b0 mm/filemap.c:4325 generic_file_write_iter+0x14b/0x690 mm/filemap.c:4468 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x629/0xba0 fs/read_write.c:688 ksys_pwrite64 fs/read_write.c:795 [inline] __do_sys_pwrite64 fs/read_write.c:803 [inline] __se_sys_pwrite64 fs/read_write.c:800 [inline] __x64_sys_pwrite64+0x19c/0x230 fs/read_write.c:800 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4201c8ce59 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:00007f41ffede028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012 RAX: ffffffffffffffda RBX: 00007f4201f05fa0 RCX: 00007f4201c8ce59 RDX: 00000000200000c1 RSI: 00002000000000c0 RDI: 0000000000000006 RBP: 00007f4201d22d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000009000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4201f06038 R14: 00007f4201f05fa0 R15: 00007ffcd56ccd38