loop0: detected capacity change from 0 to 1024 ====================================================== WARNING: possible circular locking dependency detected 6.16.0-rc7-syzkaller-00140-gec2df4364666 #0 Not tainted ------------------------------------------------------ syz.0.202/6672 is trying to acquire lock: ffff88802894d8f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0xe5/0xa40 fs/hfsplus/bitmap.c:35 but task is already holding lock: ffff88805058d8c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1ca/0x10f0 fs/hfsplus/extents.c:458 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/mutex.c:602 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:747 hfsplus_get_block+0x272/0x9d0 fs/hfsplus/extents.c:260 block_read_full_folio+0x457/0x850 fs/buffer.c:2427 filemap_read_folio+0xc8/0x2a0 mm/filemap.c:2412 do_read_cache_folio+0x263/0x5c0 mm/filemap.c:3894 do_read_cache_page mm/filemap.c:3960 [inline] read_cache_page+0x5b/0x160 mm/filemap.c:3969 read_mapping_page include/linux/pagemap.h:966 [inline] hfsplus_block_allocate+0x144/0xa40 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0x459/0x10f0 fs/hfsplus/extents.c:469 hfsplus_get_block+0x1a9/0x9d0 fs/hfsplus/extents.c:245 __block_write_begin_int+0x4f4/0x16d0 fs/buffer.c:2151 block_write_begin+0x9a/0x1d0 fs/buffer.c:2262 cont_write_begin+0x61b/0x950 fs/buffer.c:2601 hfsplus_write_begin+0x64/0x120 fs/hfsplus/inode.c:46 page_symlink+0x3fc/0x4c0 fs/namei.c:5520 hfsplus_symlink+0xd3/0x2b0 fs/hfsplus/dir.c:449 vfs_symlink fs/namei.c:4739 [inline] vfs_symlink+0x403/0x680 fs/namei.c:4723 do_symlinkat+0x261/0x310 fs/namei.c:4765 __do_sys_symlink fs/namei.c:4786 [inline] __se_sys_symlink fs/namei.c:4784 [inline] __x64_sys_symlink+0x75/0x90 fs/namei.c:4784 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 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:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain kernel/locking/lockdep.c:3911 [inline] __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240 lock_acquire kernel/locking/lockdep.c:5871 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:747 hfsplus_block_allocate+0xe5/0xa40 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0x459/0x10f0 fs/hfsplus/extents.c:469 hfsplus_bmap_reserve+0x31f/0x420 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x20d/0x10d0 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0x16fa/0x1bf0 fs/hfsplus/super.c:561 get_tree_bdev_flags+0x38c/0x620 fs/super.c:1681 vfs_get_tree+0x8e/0x340 fs/super.c:1804 do_new_mount fs/namespace.c:3902 [inline] path_mount+0x1414/0x2020 fs/namespace.c:4226 do_mount fs/namespace.c:4239 [inline] __do_sys_mount fs/namespace.c:4450 [inline] __se_sys_mount fs/namespace.c:4427 [inline] __x64_sys_mount+0x28d/0x310 fs/namespace.c:4427 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 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 *** 4 locks held by syz.0.202/6672: #0: ffff888077df00e0 (&type->s_umount_key#49/1){+.+.}-{4:4}, at: alloc_super+0x235/0xbd0 fs/super.c:345 #1: ffff88802894d998 (&sbi->vh_mutex){+.+.}-{4:4}, at: hfsplus_fill_super+0x1683/0x1bf0 fs/hfsplus/super.c:554 #2: ffff88802a52c0b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x17b/0x1f0 fs/hfsplus/bfind.c:28 #3: ffff88805058d8c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1ca/0x10f0 fs/hfsplus/extents.c:458 stack backtrace: CPU: 0 UID: 0 PID: 6672 Comm: syz.0.202 Not tainted 6.16.0-rc7-syzkaller-00140-gec2df4364666 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2046 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain kernel/locking/lockdep.c:3911 [inline] __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240 lock_acquire kernel/locking/lockdep.c:5871 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:747 hfsplus_block_allocate+0xe5/0xa40 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0x459/0x10f0 fs/hfsplus/extents.c:469 hfsplus_bmap_reserve+0x31f/0x420 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x20d/0x10d0 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0x16fa/0x1bf0 fs/hfsplus/super.c:561 get_tree_bdev_flags+0x38c/0x620 fs/super.c:1681 vfs_get_tree+0x8e/0x340 fs/super.c:1804 do_new_mount fs/namespace.c:3902 [inline] path_mount+0x1414/0x2020 fs/namespace.c:4226 do_mount fs/namespace.c:4239 [inline] __do_sys_mount fs/namespace.c:4450 [inline] __se_sys_mount fs/namespace.c:4427 [inline] __x64_sys_mount+0x28d/0x310 fs/namespace.c:4427 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa10b39014a Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa10c24be68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fa10c24bef0 RCX: 00007fa10b39014a RDX: 0000200000000100 RSI: 0000200000002900 RDI: 00007fa10c24beb0 RBP: 0000200000000100 R08: 00007fa10c24bef0 R09: 0000000002000010 R10: 0000000002000010 R11: 0000000000000246 R12: 0000200000002900 R13: 00007fa10c24beb0 R14: 00000000000006d3 R15: 0000200000000c00