loop0: detected capacity change from 0 to 1024 ====================================================== WARNING: possible circular locking dependency detected 6.17.0-rc1-syzkaller-00004-g53e760d89498 #0 Tainted: G W ------------------------------------------------------ syz.0.18/6695 is trying to acquire lock: ffff888025dba0e8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0x94/0x9b0 fs/hfsplus/bitmap.c:35 but task is already holding lock: ffff88803356b578 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1fc/0x19a0 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}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:547 hfsplus_get_block+0x3a0/0x1530 fs/hfsplus/extents.c:260 block_read_full_folio+0x29c/0x830 fs/buffer.c:2420 filemap_read_folio+0x114/0x380 mm/filemap.c:2413 do_read_cache_folio+0x2ba/0x560 mm/filemap.c:3957 do_read_cache_page mm/filemap.c:4023 [inline] read_cache_page+0x5d/0x170 mm/filemap.c:4032 read_mapping_page include/linux/pagemap.h:985 [inline] hfsplus_block_allocate+0xe4/0x9b0 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0xae3/0x19a0 fs/hfsplus/extents.c:466 hfsplus_get_block+0x413/0x1530 fs/hfsplus/extents.c:245 __block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145 block_write_begin fs/buffer.c:2256 [inline] cont_write_begin+0x789/0xb50 fs/buffer.c:2594 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 cont_expand_zero fs/buffer.c:2522 [inline] cont_write_begin+0x2fd/0xb50 fs/buffer.c:2584 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 generic_cont_expand_simple+0x13c/0x210 fs/buffer.c:2485 hfsplus_setattr+0x169/0x270 fs/hfsplus/inode.c:260 notify_change+0xb31/0xe60 fs/attr.c:552 do_truncate+0x1a4/0x220 fs/open.c:68 do_ftruncate+0x495/0x550 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] __x64_sys_ftruncate+0x92/0xf0 fs/open.c:213 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:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:547 hfsplus_block_allocate+0x94/0x9b0 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xae3/0x19a0 fs/hfsplus/extents.c:466 hfsplus_bmap_reserve+0x125/0x500 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x183/0x1020 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0x1313/0x1b70 fs/hfsplus/super.c:559 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3805 do_mount fs/namespace.c:4133 [inline] __do_sys_mount fs/namespace.c:4344 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4321 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.0.18/6695: #0: ffff88802492a0d0 (&type->s_umount_key#51/1){+.+.}-{4:4}, at: alloc_super+0x204/0x990 fs/super.c:345 #1: ffff888025dba178 (&sbi->vh_mutex){+.+.}-{4:4}, at: hfsplus_fill_super+0x1296/0x1b70 fs/hfsplus/super.c:552 #2: ffff888029f760a0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x15a/0x1d0 fs/hfsplus/bfind.c:28 #3: ffff88803356b578 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1fc/0x19a0 fs/hfsplus/extents.c:455 stack backtrace: CPU: 0 UID: 0 PID: 6695 Comm: syz.0.18 Tainted: G W 6.17.0-rc1-syzkaller-00004-g53e760d89498 #0 PREEMPT_{RT,(full)} Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043 check_noncircular+0x134/0x160 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+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:547 hfsplus_block_allocate+0x94/0x9b0 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xae3/0x19a0 fs/hfsplus/extents.c:466 hfsplus_bmap_reserve+0x125/0x500 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x183/0x1020 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0x1313/0x1b70 fs/hfsplus/super.c:559 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3805 do_mount fs/namespace.c:4133 [inline] __do_sys_mount fs/namespace.c:4344 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4321 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: 0033:0x7f7867aefeba 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:00007f7866d6de68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f7866d6def0 RCX: 00007f7867aefeba RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f7866d6deb0 RBP: 0000000020000000 R08: 00007f7866d6def0 R09: 000000000180000c R10: 000000000180000c R11: 0000000000000246 R12: 0000000020000100 R13: 00007f7866d6deb0 R14: 00000000000006ed R15: 0000000020000900