====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.6.215/8175 is trying to acquire lock: ffff0000e732c0f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0x94/0x91c fs/hfsplus/bitmap.c:35 but task is already holding lock: ffff0000d4190108 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1b8/0x1530 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+0x1d0/0x2678 kernel/locking/mutex.c:598 __mutex_lock kernel/locking/mutex.c:760 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812 hfsplus_get_block+0x2d4/0x1244 fs/hfsplus/extents.c:260 block_read_full_folio+0x2ec/0x824 fs/buffer.c:2420 hfsplus_read_folio+0x28/0x38 fs/hfsplus/inode.c:28 filemap_read_folio+0xec/0x2f8 mm/filemap.c:2444 do_read_cache_folio+0x364/0x5bc mm/filemap.c:4024 do_read_cache_page mm/filemap.c:4090 [inline] read_cache_page+0x6c/0x160 mm/filemap.c:4099 read_mapping_page include/linux/pagemap.h:993 [inline] hfsplus_block_allocate+0xe4/0x91c fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0x774/0x1530 fs/hfsplus/extents.c:464 hfsplus_get_block+0x32c/0x1244 fs/hfsplus/extents.c:245 __block_write_begin_int+0x53c/0x15e8 fs/buffer.c:2145 block_write_begin fs/buffer.c:2256 [inline] cont_write_begin+0x62c/0x968 fs/buffer.c:2594 hfsplus_write_begin+0x7c/0xc4 fs/hfsplus/inode.c:48 generic_perform_write+0x244/0x7bc mm/filemap.c:4242 __generic_file_write_iter+0xfc/0x204 mm/filemap.c:4359 generic_file_write_iter+0x10c/0x47c mm/filemap.c:4385 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x540/0xa3c fs/read_write.c:686 ksys_write+0x120/0x210 fs/read_write.c:738 __do_sys_write fs/read_write.c:749 [inline] __se_sys_write fs/read_write.c:746 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:746 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:746 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 -> #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+0x1774/0x30a4 kernel/locking/lockdep.c:5237 lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868 __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:598 __mutex_lock kernel/locking/mutex.c:760 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812 hfsplus_block_allocate+0x94/0x91c fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0x774/0x1530 fs/hfsplus/extents.c:464 hfsplus_get_block+0x32c/0x1244 fs/hfsplus/extents.c:245 __block_write_begin_int+0x53c/0x15e8 fs/buffer.c:2145 block_write_begin fs/buffer.c:2256 [inline] cont_write_begin+0x62c/0x968 fs/buffer.c:2594 hfsplus_write_begin+0x7c/0xc4 fs/hfsplus/inode.c:48 cont_expand_zero fs/buffer.c:2522 [inline] cont_write_begin+0x26c/0x968 fs/buffer.c:2584 hfsplus_write_begin+0x7c/0xc4 fs/hfsplus/inode.c:48 generic_perform_write+0x244/0x7bc mm/filemap.c:4242 __generic_file_write_iter+0xfc/0x204 mm/filemap.c:4359 generic_file_write_iter+0x10c/0x47c mm/filemap.c:4385 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x540/0xa3c fs/read_write.c:686 ksys_pwrite64 fs/read_write.c:793 [inline] __do_sys_pwrite64 fs/read_write.c:801 [inline] __se_sys_pwrite64 fs/read_write.c:798 [inline] __arm64_sys_pwrite64+0x170/0x208 fs/read_write.c:798 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:746 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 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.6.215/8175: #0: ffff0000ca1a0420 (sb_writers#31){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3111 [inline] #0: ffff0000ca1a0420 (sb_writers#31){.+.+}-{0:0}, at: vfs_write+0x24c/0xa3c fs/read_write.c:682 #1: ffff0000d41902f8 (&sb->s_type->i_mutex_key#39){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #1: ffff0000d41902f8 (&sb->s_type->i_mutex_key#39){+.+.}-{4:4}, at: generic_file_write_iter+0xdc/0x47c mm/filemap.c:4382 #2: ffff0000d4190108 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1b8/0x1530 fs/hfsplus/extents.c:453 stack backtrace: CPU: 1 UID: 0 PID: 8175 Comm: syz.6.215 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 dump_stack+0x1c/0x28 lib/dump_stack.c:129 print_circular_bug+0x324/0x32c kernel/locking/lockdep.c:2043 check_noncircular+0x154/0x174 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+0x1774/0x30a4 kernel/locking/lockdep.c:5237 lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868 __mutex_lock_common+0x1d0/0x2678 kernel/locking/mutex.c:598 __mutex_lock kernel/locking/mutex.c:760 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812 hfsplus_block_allocate+0x94/0x91c fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0x774/0x1530 fs/hfsplus/extents.c:464 hfsplus_get_block+0x32c/0x1244 fs/hfsplus/extents.c:245 __block_write_begin_int+0x53c/0x15e8 fs/buffer.c:2145 block_write_begin fs/buffer.c:2256 [inline] cont_write_begin+0x62c/0x968 fs/buffer.c:2594 hfsplus_write_begin+0x7c/0xc4 fs/hfsplus/inode.c:48 cont_expand_zero fs/buffer.c:2522 [inline] cont_write_begin+0x26c/0x968 fs/buffer.c:2584 hfsplus_write_begin+0x7c/0xc4 fs/hfsplus/inode.c:48 generic_perform_write+0x244/0x7bc mm/filemap.c:4242 __generic_file_write_iter+0xfc/0x204 mm/filemap.c:4359 generic_file_write_iter+0x10c/0x47c mm/filemap.c:4385 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x540/0xa3c fs/read_write.c:686 ksys_pwrite64 fs/read_write.c:793 [inline] __do_sys_pwrite64 fs/read_write.c:801 [inline] __se_sys_pwrite64 fs/read_write.c:798 [inline] __arm64_sys_pwrite64+0x170/0x208 fs/read_write.c:798 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:746 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596