loop6: detected capacity change from 0 to 1024 ====================================================== WARNING: possible circular locking dependency detected 6.16.0-rc2-syzkaller-00378-gb67ec639010f #0 Not tainted ------------------------------------------------------ syz.6.425/8824 is trying to acquire lock: ffff88802fd4a0f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0x94/0x9b0 fs/hfsplus/bitmap.c:35 but task is already holding lock: ffff8880317673c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1fc/0x1990 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}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 hfsplus_get_block+0x39e/0x1530 fs/hfsplus/extents.c:260 block_read_full_folio+0x29c/0x830 fs/buffer.c:2427 filemap_read_folio+0x117/0x380 mm/filemap.c:2412 do_read_cache_folio+0x350/0x590 mm/filemap.c:3894 do_read_cache_page mm/filemap.c:3960 [inline] read_cache_page+0x5d/0x170 mm/filemap.c:3969 read_mapping_page include/linux/pagemap.h:966 [inline] hfsplus_block_allocate+0xe4/0x9b0 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0xae3/0x1990 fs/hfsplus/extents.c:469 hfsplus_get_block+0x411/0x1530 fs/hfsplus/extents.c:245 __block_write_begin_int+0x6b2/0x1900 fs/buffer.c:2151 block_write_begin fs/buffer.c:2262 [inline] cont_write_begin+0x789/0xb50 fs/buffer.c:2601 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:46 cont_expand_zero fs/buffer.c:2528 [inline] cont_write_begin+0x2fa/0xb50 fs/buffer.c:2591 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:46 generic_perform_write+0x2c7/0x910 mm/filemap.c:4112 generic_file_write_iter+0x10f/0x540 mm/filemap.c:4255 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x548/0xa90 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] __x64_sys_pwrite64+0x193/0x220 fs/read_write.c:798 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 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+0xb9b/0x2140 kernel/locking/lockdep.c:3911 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 hfsplus_block_allocate+0x94/0x9b0 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xae3/0x1990 fs/hfsplus/extents.c:469 hfsplus_bmap_reserve+0x122/0x500 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x183/0x1000 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0x1314/0x1b70 fs/hfsplus/super.c:561 get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1681 vfs_get_tree+0x92/0x2b0 fs/super.c:1804 do_new_mount+0x24a/0xa40 fs/namespace.c:3885 do_mount fs/namespace.c:4222 [inline] __do_sys_mount fs/namespace.c:4433 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4410 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 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.6.425/8824: #0: ffff888030b4c0e0 (&type->s_umount_key#60/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970 fs/super.c:345 #1: ffff88802fd4a198 (&sbi->vh_mutex){+.+.}-{4:4}, at: hfsplus_fill_super+0x1297/0x1b70 fs/hfsplus/super.c:554 #2: ffff88802a03e0b0 (&tree->tree_lock#2){+.+.}-{4:4}, at: hfsplus_find_init+0x15a/0x1d0 fs/hfsplus/bfind.c:28 #3: ffff8880317673c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1fc/0x1990 fs/hfsplus/extents.c:458 stack backtrace: CPU: 1 UID: 0 PID: 8824 Comm: syz.6.425 Not tainted 6.16.0-rc2-syzkaller-00378-gb67ec639010f #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2046 check_noncircular+0x134/0x160 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+0xb9b/0x2140 kernel/locking/lockdep.c:3911 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747 hfsplus_block_allocate+0x94/0x9b0 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xae3/0x1990 fs/hfsplus/extents.c:469 hfsplus_bmap_reserve+0x122/0x500 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x183/0x1000 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0x1314/0x1b70 fs/hfsplus/super.c:561 get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1681 vfs_get_tree+0x92/0x2b0 fs/super.c:1804 do_new_mount+0x24a/0xa40 fs/namespace.c:3885 do_mount fs/namespace.c:4222 [inline] __do_sys_mount fs/namespace.c:4433 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4410 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fecfdd900ca 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:00007fecfebefe68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fecfebefef0 RCX: 00007fecfdd900ca RDX: 0000200000000100 RSI: 0000200000000180 RDI: 00007fecfebefeb0 RBP: 0000200000000100 R08: 00007fecfebefef0 R09: 0000000002000010 R10: 0000000002000010 R11: 0000000000000246 R12: 0000200000000180 R13: 00007fecfebefeb0 R14: 00000000000006f0 R15: 00002000000022c0 hfsplus: xattr search failed