loop4: detected capacity change from 0 to 64 ====================================================== WARNING: possible circular locking dependency detected 6.6.95-syzkaller #0 Not tainted ------------------------------------------------------ syz.4.1845/10623 is trying to acquire lock: ffff888077a800b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfs_find_init+0x15f/0x1d0 fs/hfs/bfind.c:-1 but task is already holding lock: ffff888058ec8778 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xdb/0x1220 fs/hfs/extent.c:397 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x129/0xcc0 kernel/locking/mutex.c:747 hfs_extend_file+0xdb/0x1220 fs/hfs/extent.c:397 hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:234 __hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x6b/0x9b0 fs/hfs/extent.c:174 hfs_ext_read_extent fs/hfs/extent.c:202 [inline] hfs_extend_file+0x317/0x1220 fs/hfs/extent.c:401 hfs_get_block+0x3d8/0xbd0 fs/hfs/extent.c:353 get_more_blocks fs/direct-io.c:647 [inline] do_direct_IO fs/direct-io.c:935 [inline] __blockdev_direct_IO+0x1679/0x3420 fs/direct-io.c:1248 blockdev_direct_IO include/linux/fs.h:3047 [inline] hfs_direct_IO+0x11b/0x220 fs/hfs/inode.c:138 generic_file_direct_write+0x1d4/0x3e0 mm/filemap.c:3941 __generic_file_write_iter+0x11b/0x230 mm/filemap.c:4097 generic_file_write_iter+0xaf/0x2e0 mm/filemap.c:4137 do_iter_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x79a/0xc70 fs/read_write.c:860 vfs_writev fs/read_write.c:933 [inline] do_writev+0x252/0x410 fs/read_write.c:976 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&tree->tree_lock#2/1){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x129/0xcc0 kernel/locking/mutex.c:747 hfs_find_init+0x15f/0x1d0 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_extend_file+0x2ef/0x1220 fs/hfs/extent.c:401 hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:234 hfs_cat_create+0x1b4/0x620 fs/hfs/catalog.c:104 hfs_create+0x66/0xd0 fs/hfs/dir.c:202 lookup_open fs/namei.c:3488 [inline] open_last_lookups fs/namei.c:3556 [inline] path_openat+0x1277/0x3190 fs/namei.c:3786 do_filp_open+0x1c5/0x3d0 fs/namei.c:3816 do_sys_openat2+0x12c/0x1c0 fs/open.c:1419 do_sys_open fs/open.c:1434 [inline] __do_sys_openat fs/open.c:1450 [inline] __se_sys_openat fs/open.c:1445 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1445 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&HFS_I(tree->inode)->extents_lock); lock(&tree->tree_lock#2/1); lock(&HFS_I(tree->inode)->extents_lock); lock(&tree->tree_lock#2/1); *** DEADLOCK *** 4 locks held by syz.4.1845/10623: #0: ffff888058c0e418 (sb_writers#31){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:403 #1: ffff888058ec8fb8 (&type->i_mutex_dir_key#15){++++}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #1: ffff888058ec8fb8 (&type->i_mutex_dir_key#15){++++}-{3:3}, at: open_last_lookups fs/namei.c:3553 [inline] #1: ffff888058ec8fb8 (&type->i_mutex_dir_key#15){++++}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3786 #2: ffff8880778d80b0 (&tree->tree_lock#2){+.+.}-{3:3}, at: hfs_find_init+0x15f/0x1d0 fs/hfs/bfind.c:-1 #3: ffff888058ec8778 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xdb/0x1220 fs/hfs/extent.c:397 stack backtrace: CPU: 0 PID: 10623 Comm: syz.4.1845 Not tainted 6.6.95-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 check_noncircular+0x2bd/0x3c0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x129/0xcc0 kernel/locking/mutex.c:747 hfs_find_init+0x15f/0x1d0 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_extend_file+0x2ef/0x1220 fs/hfs/extent.c:401 hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:234 hfs_cat_create+0x1b4/0x620 fs/hfs/catalog.c:104 hfs_create+0x66/0xd0 fs/hfs/dir.c:202 lookup_open fs/namei.c:3488 [inline] open_last_lookups fs/namei.c:3556 [inline] path_openat+0x1277/0x3190 fs/namei.c:3786 do_filp_open+0x1c5/0x3d0 fs/namei.c:3816 do_sys_openat2+0x12c/0x1c0 fs/open.c:1419 do_sys_open fs/open.c:1434 [inline] __do_sys_openat fs/open.c:1450 [inline] __se_sys_openat fs/open.c:1445 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1445 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fcd3bb8e929 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:00007fcd3c97b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fcd3bdb5fa0 RCX: 00007fcd3bb8e929 RDX: 0000000000105042 RSI: 0000200000000180 RDI: ffffffffffffff9c RBP: 00007fcd3bc10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000189 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fcd3bdb5fa0 R15: 00007ffd617a7d88