loop0: detected capacity change from 0 to 1024 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.17/7503 is trying to acquire lock: ffff0000d969a8f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0x88/0x70c fs/hfsplus/bitmap.c:35 but task is already holding lock: ffff0000c66bdf88 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1b8/0x1388 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+0x1d0/0x24ac 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+0x2bc/0x1154 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:2413 do_read_cache_folio+0x364/0x5bc mm/filemap.c:3957 do_read_cache_page mm/filemap.c:4023 [inline] read_cache_page+0x6c/0x160 mm/filemap.c:4032 read_mapping_page include/linux/pagemap.h:985 [inline] hfsplus_block_allocate+0xdc/0x70c fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0x770/0x1388 fs/hfsplus/extents.c:466 hfsplus_get_block+0x314/0x1154 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:4175 __generic_file_write_iter+0xfc/0x204 mm/filemap.c:4292 generic_file_write_iter+0x10c/0x47c mm/filemap.c:4318 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+0x98/0x2b8 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+0x58/0x180 arch/arm64/kernel/entry-common.c:879 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898 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+0x1d0/0x24ac 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+0x88/0x70c fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0x770/0x1388 fs/hfsplus/extents.c:466 hfsplus_bmap_reserve+0xe8/0x494 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x170/0xdc8 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0xfa4/0x16fc fs/hfsplus/super.c:559 get_tree_bdev_flags+0x360/0x414 fs/super.c:1692 get_tree_bdev+0x2c/0x3c fs/super.c:1715 hfsplus_get_tree+0x28/0x38 fs/hfsplus/super.c:638 vfs_get_tree+0x90/0x28c fs/super.c:1815 do_new_mount+0x278/0x7f4 fs/namespace.c:3805 path_mount+0x5b4/0xde0 fs/namespace.c:4120 do_mount fs/namespace.c:4133 [inline] __do_sys_mount fs/namespace.c:4344 [inline] __se_sys_mount fs/namespace.c:4321 [inline] __arm64_sys_mount+0x3e8/0x468 fs/namespace.c:4321 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 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+0x58/0x180 arch/arm64/kernel/entry-common.c:879 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898 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 *** 4 locks held by syz.0.17/7503: #0: ffff0000db0040e0 (&type->s_umount_key#51/1){+.+.}-{4:4}, at: alloc_super+0x1a0/0x80c fs/super.c:345 #1: ffff0000d969a998 (&sbi->vh_mutex){+.+.}-{4:4}, at: hfsplus_fill_super+0xf4c/0x16fc fs/hfsplus/super.c:552 #2: ffff0000cc9a00b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x144/0x1bc fs/hfsplus/bfind.c:28 #3: ffff0000c66bdf88 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1b8/0x1388 fs/hfsplus/extents.c:455 stack backtrace: CPU: 0 UID: 0 PID: 7503 Comm: syz.0.17 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+0x1d0/0x24ac 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+0x88/0x70c fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0x770/0x1388 fs/hfsplus/extents.c:466 hfsplus_bmap_reserve+0xe8/0x494 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x170/0xdc8 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0xfa4/0x16fc fs/hfsplus/super.c:559 get_tree_bdev_flags+0x360/0x414 fs/super.c:1692 get_tree_bdev+0x2c/0x3c fs/super.c:1715 hfsplus_get_tree+0x28/0x38 fs/hfsplus/super.c:638 vfs_get_tree+0x90/0x28c fs/super.c:1815 do_new_mount+0x278/0x7f4 fs/namespace.c:3805 path_mount+0x5b4/0xde0 fs/namespace.c:4120 do_mount fs/namespace.c:4133 [inline] __do_sys_mount fs/namespace.c:4344 [inline] __se_sys_mount fs/namespace.c:4321 [inline] __arm64_sys_mount+0x3e8/0x468 fs/namespace.c:4321 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 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+0x58/0x180 arch/arm64/kernel/entry-common.c:879 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 hfsplus: xattr search failed