loop7: detected capacity change from 0 to 64 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.7.3118/15031 is trying to acquire lock: ffff88805a25d578 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xfb/0x13f0 fs/hfs/extent.c:397 but task is already holding lock: ffff8880587280b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x15b/0x1d0 fs/hfs/bfind.c:-1 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&tree->tree_lock/1){+.+.}-{3:3}: __mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 hfs_find_init+0x15b/0x1d0 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_extend_file+0x35d/0x13f0 fs/hfs/extent.c:401 hfs_bmap_reserve+0x103/0x420 fs/hfs/btree.c:231 hfs_cat_create+0x204/0x8e0 fs/hfs/catalog.c:104 hfs_mkdir+0x68/0xe0 fs/hfs/dir.c:232 vfs_mkdir+0x387/0x570 fs/namei.c:4073 do_mkdirat+0x1df/0x5b0 fs/namei.c:4098 __do_sys_mkdirat fs/namei.c:4113 [inline] __se_sys_mkdirat fs/namei.c:4111 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4111 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 hfs_extend_file+0xfb/0x13f0 fs/hfs/extent.c:397 hfs_bmap_reserve+0x103/0x420 fs/hfs/btree.c:231 __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+0x39c/0x13f0 fs/hfs/extent.c:401 hfs_get_block+0x40f/0xc50 fs/hfs/extent.c:353 __block_write_begin_int+0x565/0x15d0 fs/buffer.c:2012 __block_write_begin fs/buffer.c:2062 [inline] block_write_begin fs/buffer.c:2122 [inline] cont_write_begin+0x598/0x7b0 fs/buffer.c:2471 hfs_write_begin+0x92/0xe0 fs/hfs/inode.c:59 cont_expand_zero fs/buffer.c:2398 [inline] cont_write_begin+0x263/0x7b0 fs/buffer.c:2461 hfs_write_begin+0x92/0xe0 fs/hfs/inode.c:59 hfs_file_truncate+0x1c2/0xa10 fs/hfs/extent.c:494 hfs_inode_setattr+0x4ab/0x6f0 fs/hfs/inode.c:657 notify_change+0xbcd/0xee0 fs/attr.c:505 do_truncate+0x1ac/0x240 fs/open.c:65 do_sys_ftruncate+0x31b/0x3d0 fs/open.c:193 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&tree->tree_lock/1); lock(&HFS_I(tree->inode)->extents_lock); lock(&tree->tree_lock/1); lock(&HFS_I(tree->inode)->extents_lock); *** DEADLOCK *** 4 locks held by syz.7.3118/15031: #0: ffff88804f9be460 (sb_writers#14){.+.+}-{0:0}, at: do_sys_ftruncate+0x284/0x3d0 fs/open.c:190 #1: ffff88807b7b82a8 (&sb->s_type->i_mutex_key#22){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff88807b7b82a8 (&sb->s_type->i_mutex_key#22){+.+.}-{3:3}, at: do_truncate+0x198/0x240 fs/open.c:63 #2: ffff88807b7b80f8 (&HFS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xfb/0x13f0 fs/hfs/extent.c:397 #3: ffff8880587280b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x15b/0x1d0 fs/hfs/bfind.c:-1 stack backtrace: CPU: 1 PID: 15031 Comm: syz.7.3118 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 hfs_extend_file+0xfb/0x13f0 fs/hfs/extent.c:397 hfs_bmap_reserve+0x103/0x420 fs/hfs/btree.c:231 __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+0x39c/0x13f0 fs/hfs/extent.c:401 hfs_get_block+0x40f/0xc50 fs/hfs/extent.c:353 __block_write_begin_int+0x565/0x15d0 fs/buffer.c:2012 __block_write_begin fs/buffer.c:2062 [inline] block_write_begin fs/buffer.c:2122 [inline] cont_write_begin+0x598/0x7b0 fs/buffer.c:2471 hfs_write_begin+0x92/0xe0 fs/hfs/inode.c:59 cont_expand_zero fs/buffer.c:2398 [inline] cont_write_begin+0x263/0x7b0 fs/buffer.c:2461 hfs_write_begin+0x92/0xe0 fs/hfs/inode.c:59 hfs_file_truncate+0x1c2/0xa10 fs/hfs/extent.c:494 hfs_inode_setattr+0x4ab/0x6f0 fs/hfs/inode.c:657 notify_change+0xbcd/0xee0 fs/attr.c:505 do_truncate+0x1ac/0x240 fs/open.c:65 do_sys_ftruncate+0x31b/0x3d0 fs/open.c:193 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fac507fce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fac4ea56028 EFLAGS: 00000246 ORIG_RAX: 000000000000004d RAX: ffffffffffffffda RBX: 00007fac50a75fa0 RCX: 00007fac507fce59 RDX: 0000000000000000 RSI: 0000000002000009 RDI: 0000000000000005 RBP: 00007fac50892d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fac50a76038 R14: 00007fac50a75fa0 R15: 00007ffd2698a598