loop6: detected capacity change from 0 to 1024 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.6.2359/11230 is trying to acquire lock: ffff0000fa8c3dc8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_get_block+0x2c0/0x11a0 fs/hfsplus/extents.c:260 but task is already holding lock: ffff0000dc8600f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x88/0x7e4 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+0x190/0x1f60 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 hfsplus_block_allocate+0x88/0x7e4 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0x7a0/0x13b4 fs/hfsplus/extents.c:466 hfsplus_bmap_reserve+0xe8/0x494 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x19c/0xe24 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0xf74/0x1654 fs/hfsplus/super.c:579 mount_bdev+0x264/0x358 fs/super.c:1443 hfsplus_mount+0x44/0x58 fs/hfsplus/super.c:660 legacy_get_tree+0xd4/0x16c fs/fs_context.c:632 vfs_get_tree+0x90/0x274 fs/super.c:1573 do_new_mount+0x228/0x810 fs/namespace.c:3078 path_mount+0x5bc/0xe80 fs/namespace.c:3408 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount fs/namespace.c:3606 [inline] __arm64_sys_mount+0x49c/0x59c fs/namespace.c:3606 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 -> #0 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2880/0x6800 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662 __mutex_lock_common+0x190/0x1f60 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 hfsplus_get_block+0x2c0/0x11a0 fs/hfsplus/extents.c:260 block_read_full_folio+0x2f4/0x980 fs/buffer.c:2271 hfsplus_read_folio+0x28/0x38 fs/hfsplus/inode.c:28 filemap_read_folio+0x134/0x384 mm/filemap.c:2490 do_read_cache_folio+0x24c/0x538 mm/filemap.c:3659 do_read_cache_page mm/filemap.c:3701 [inline] read_cache_page+0x6c/0x184 mm/filemap.c:3710 read_mapping_page include/linux/pagemap.h:793 [inline] hfsplus_block_allocate+0xd8/0x7e4 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0x7a0/0x13b4 fs/hfsplus/extents.c:466 hfsplus_get_block+0x324/0x11a0 fs/hfsplus/extents.c:245 __block_write_begin_int+0x350/0x1388 fs/buffer.c:1991 __block_write_begin fs/buffer.c:2041 [inline] block_write_begin fs/buffer.c:2102 [inline] cont_write_begin+0x53c/0x780 fs/buffer.c:2456 hfsplus_write_begin+0x98/0xe4 fs/hfsplus/inode.c:52 cont_expand_zero fs/buffer.c:2416 [inline] cont_write_begin+0x5d8/0x780 fs/buffer.c:2446 hfsplus_write_begin+0x98/0xe4 fs/hfsplus/inode.c:52 generic_perform_write+0x234/0x4f4 mm/filemap.c:3862 __generic_file_write_iter+0x130/0x250 mm/filemap.c:3960 generic_file_write_iter+0xb4/0x2b0 mm/filemap.c:3989 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x3ec/0x7f0 fs/read_write.c:584 ksys_pwrite64 fs/read_write.c:699 [inline] __do_sys_pwrite64 fs/read_write.c:709 [inline] __se_sys_pwrite64 fs/read_write.c:706 [inline] __arm64_sys_pwrite64+0x174/0x20c fs/read_write.c:706 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 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 *** 4 locks held by syz.6.2359/11230: #0: ffff0000d3a20460 (sb_writers#29){.+.+}-{0:0}, at: vfs_write+0x244/0x7f0 fs/read_write.c:580 #1: ffff0000fa8c2b80 (&sb->s_type->i_mutex_key#37){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff0000fa8c2b80 (&sb->s_type->i_mutex_key#37){+.+.}-{3:3}, at: generic_file_write_iter+0x84/0x2b0 mm/filemap.c:3986 #2: ffff0000fa8c2988 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x18c/0x13b4 fs/hfsplus/extents.c:455 #3: ffff0000dc8600f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x88/0x7e4 fs/hfsplus/bitmap.c:35 stack backtrace: CPU: 1 PID: 11230 Comm: syz.6.2359 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call trace: dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2048 check_noncircular+0x264/0x2f8 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2880/0x6800 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662 __mutex_lock_common+0x190/0x1f60 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 hfsplus_get_block+0x2c0/0x11a0 fs/hfsplus/extents.c:260 block_read_full_folio+0x2f4/0x980 fs/buffer.c:2271 hfsplus_read_folio+0x28/0x38 fs/hfsplus/inode.c:28 filemap_read_folio+0x134/0x384 mm/filemap.c:2490 do_read_cache_folio+0x24c/0x538 mm/filemap.c:3659 do_read_cache_page mm/filemap.c:3701 [inline] read_cache_page+0x6c/0x184 mm/filemap.c:3710 read_mapping_page include/linux/pagemap.h:793 [inline] hfsplus_block_allocate+0xd8/0x7e4 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0x7a0/0x13b4 fs/hfsplus/extents.c:466 hfsplus_get_block+0x324/0x11a0 fs/hfsplus/extents.c:245 __block_write_begin_int+0x350/0x1388 fs/buffer.c:1991 __block_write_begin fs/buffer.c:2041 [inline] block_write_begin fs/buffer.c:2102 [inline] cont_write_begin+0x53c/0x780 fs/buffer.c:2456 hfsplus_write_begin+0x98/0xe4 fs/hfsplus/inode.c:52 cont_expand_zero fs/buffer.c:2416 [inline] cont_write_begin+0x5d8/0x780 fs/buffer.c:2446 hfsplus_write_begin+0x98/0xe4 fs/hfsplus/inode.c:52 generic_perform_write+0x234/0x4f4 mm/filemap.c:3862 __generic_file_write_iter+0x130/0x250 mm/filemap.c:3960 generic_file_write_iter+0xb4/0x2b0 mm/filemap.c:3989 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x3ec/0x7f0 fs/read_write.c:584 ksys_pwrite64 fs/read_write.c:699 [inline] __do_sys_pwrite64 fs/read_write.c:709 [inline] __se_sys_pwrite64 fs/read_write.c:706 [inline] __arm64_sys_pwrite64+0x174/0x20c fs/read_write.c:706 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585