loop6: detected capacity change from 0 to 1024 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.6.352/9121 is trying to acquire lock: ffff0000cc8c30f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0x94/0x91c fs/hfsplus/bitmap.c:35 but task is already holding lock: ffff0000dfb13048 (&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 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_cont_expand_simple+0x12c/0x1fc fs/buffer.c:2485 hfsplus_setattr+0x140/0x24c fs/hfsplus/inode.c:260 notify_change+0xa0c/0xcb8 fs/attr.c:546 do_truncate+0x198/0x210 fs/open.c:68 do_ftruncate+0x3bc/0x458 fs/open.c:195 do_sys_ftruncate fs/open.c:210 [inline] __do_sys_ftruncate fs/open.c:215 [inline] __se_sys_ftruncate fs/open.c:213 [inline] __arm64_sys_ftruncate+0x90/0xe8 fs/open.c:213 __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_bmap_reserve+0xe8/0x494 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x178/0xe98 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0xfa4/0x16fc fs/hfsplus/super.c:580 get_tree_bdev_flags+0x360/0x414 fs/super.c:1691 get_tree_bdev+0x2c/0x3c fs/super.c:1714 hfsplus_get_tree+0x28/0x38 fs/hfsplus/super.c:659 vfs_get_tree+0x90/0x28c fs/super.c:1751 fc_mount fs/namespace.c:1208 [inline] do_new_mount_fc fs/namespace.c:3651 [inline] do_new_mount+0x284/0x944 fs/namespace.c:3727 path_mount+0x5b4/0xdfc fs/namespace.c:4037 do_mount fs/namespace.c:4050 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount fs/namespace.c:4215 [inline] __arm64_sys_mount+0x3e8/0x468 fs/namespace.c:4215 __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 *** 4 locks held by syz.6.352/9121: #0: ffff0000ef8b40e0 (&type->s_umount_key#65/1){+.+.}-{4:4}, at: alloc_super+0x168/0x7d4 fs/super.c:344 #1: ffff0000cc8c3198 (&sbi->vh_mutex){+.+.}-{4:4}, at: hfsplus_fill_super+0xf4c/0x16fc fs/hfsplus/super.c:573 #2: ffff0000f8c800b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x154/0x278 fs/hfsplus/bfind.c:28 #3: ffff0000dfb13048 (&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: 9121 Comm: syz.6.352 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_bmap_reserve+0xe8/0x494 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x178/0xe98 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0xfa4/0x16fc fs/hfsplus/super.c:580 get_tree_bdev_flags+0x360/0x414 fs/super.c:1691 get_tree_bdev+0x2c/0x3c fs/super.c:1714 hfsplus_get_tree+0x28/0x38 fs/hfsplus/super.c:659 vfs_get_tree+0x90/0x28c fs/super.c:1751 fc_mount fs/namespace.c:1208 [inline] do_new_mount_fc fs/namespace.c:3651 [inline] do_new_mount+0x284/0x944 fs/namespace.c:3727 path_mount+0x5b4/0xdfc fs/namespace.c:4037 do_mount fs/namespace.c:4050 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount fs/namespace.c:4215 [inline] __arm64_sys_mount+0x3e8/0x468 fs/namespace.c:4215 __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 hfsplus: xattr search failed hfsplus: b-tree write err: -5, ino 4