loop4: detected capacity change from 0 to 1024 ====================================================== WARNING: possible circular locking dependency detected 6.17.0-rc1-syzkaller #0 Not tainted ------------------------------------------------------ syz.4.889/10024 is trying to acquire lock: ffff88807d833708 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_get_block+0x39e/0x1530 fs/hfsplus/extents.c:260 but task is already holding lock: ffff8880321cd8f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0x94/0x9b0 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){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1360 kernel/locking/mutex.c:760 hfsplus_block_allocate+0x94/0x9b0 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xae3/0x1990 fs/hfsplus/extents.c:466 hfsplus_bmap_reserve+0x122/0x500 fs/hfsplus/btree.c:358 hfsplus_create_cat+0x183/0x1000 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0x12f5/0x1b50 fs/hfsplus/super.c:559 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692 vfs_get_tree+0x92/0x2b0 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 -> #0 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{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/mutex.c:598 [inline] __mutex_lock+0x187/0x1360 kernel/locking/mutex.c:760 hfsplus_get_block+0x39e/0x1530 fs/hfsplus/extents.c:260 block_read_full_folio+0x29f/0x830 fs/buffer.c:2420 filemap_read_folio+0x117/0x380 mm/filemap.c:2413 do_read_cache_folio+0x350/0x590 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+0xae3/0x1990 fs/hfsplus/extents.c:466 hfsplus_get_block+0x411/0x1530 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 generic_perform_write+0x2c5/0x900 mm/filemap.c:4175 generic_file_write_iter+0x117/0x550 mm/filemap.c:4318 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 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(&sbi->alloc_mutex); lock(&HFSPLUS_I(inode)->extents_lock); lock(&sbi->alloc_mutex); lock(&HFSPLUS_I(inode)->extents_lock); *** DEADLOCK *** 5 locks held by syz.4.889/10024: #0: ffff8880277309b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1232 #1: ffff88806968e428 (sb_writers#18){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3107 [inline] #1: ffff88806968e428 (sb_writers#18){.+.+}-{0:0}, at: vfs_write+0x211/0xb30 fs/read_write.c:682 #2: ffff88807d836178 (&sb->s_type->i_mutex_key#25){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #2: ffff88807d836178 (&sb->s_type->i_mutex_key#25){+.+.}-{4:4}, at: generic_file_write_iter+0xeb/0x550 mm/filemap.c:4315 #3: ffff88807d835f88 (&hip->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1fc/0x1990 fs/hfsplus/extents.c:455 #4: ffff8880321cd8f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0x94/0x9b0 fs/hfsplus/bitmap.c:35 stack backtrace: CPU: 0 UID: 0 PID: 10024 Comm: syz.4.889 Not tainted 6.17.0-rc1-syzkaller #0 PREEMPT(full) 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/mutex.c:598 [inline] __mutex_lock+0x187/0x1360 kernel/locking/mutex.c:760 hfsplus_get_block+0x39e/0x1530 fs/hfsplus/extents.c:260 block_read_full_folio+0x29f/0x830 fs/buffer.c:2420 filemap_read_folio+0x117/0x380 mm/filemap.c:2413 do_read_cache_folio+0x350/0x590 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+0xae3/0x1990 fs/hfsplus/extents.c:466 hfsplus_get_block+0x411/0x1530 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 generic_perform_write+0x2c5/0x900 mm/filemap.c:4175 generic_file_write_iter+0x117/0x550 mm/filemap.c:4318 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 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: 0033:0x7fce8e78ebe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007fce8f613038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fce8e9b5fa0 RCX: 00007fce8e78ebe9 RDX: 000000000001000a RSI: 0000200000010640 RDI: 0000000000000005 RBP: 00007fce8e811e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fce8e9b6038 R14: 00007fce8e9b5fa0 R15: 00007ffe2ad09168