====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.227/5329 is trying to acquire lock: ffff888056eb9af8 (&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: ffff88807e33c0b0 (&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 kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 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:234 hfs_cat_create+0x204/0x8e0 fs/hfs/catalog.c:104 hfs_create+0x62/0xd0 fs/hfs/dir.c:202 lookup_open fs/namei.c:3490 [inline] open_last_lookups fs/namei.c:3558 [inline] path_openat+0x1181/0x2ee0 fs/namei.c:3788 do_filp_open+0x1f1/0x430 fs/namei.c:3818 do_sys_openat2+0x150/0x4b0 fs/open.c:1320 do_sys_open fs/open.c:1336 [inline] __do_sys_open fs/open.c:1344 [inline] __se_sys_open fs/open.c:1340 [inline] __x64_sys_open+0x11b/0x140 fs/open.c:1340 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 hfs_extend_file+0xfb/0x13f0 fs/hfs/extent.c:397 hfs_bmap_reserve+0x103/0x420 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+0x39c/0x13f0 fs/hfs/extent.c:401 hfs_get_block+0x40f/0xc50 fs/hfs/extent.c:353 __block_write_begin_int+0x55d/0x1a80 fs/buffer.c:1991 __block_write_begin fs/buffer.c:2041 [inline] block_write_begin+0x96/0x1e0 fs/buffer.c:2102 cont_write_begin+0x5ea/0x800 fs/buffer.c:2456 hfs_write_begin+0x87/0xd0 fs/hfs/inode.c:58 cont_expand_zero fs/buffer.c:2383 [inline] cont_write_begin+0x2ad/0x800 fs/buffer.c:2446 hfs_write_begin+0x87/0xd0 fs/hfs/inode.c:58 hfs_file_truncate+0x1c0/0xa10 fs/hfs/extent.c:494 hfs_inode_setattr+0x4ab/0x6f0 fs/hfs/inode.c:659 notify_change+0xc74/0xf40 fs/attr.c:499 do_truncate+0x1ac/0x240 fs/open.c:65 vfs_truncate+0x262/0x2f0 fs/open.c:111 do_sys_truncate+0xf2/0x1c0 fs/open.c:134 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 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.0.227/5329: #0: ffff888053486460 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402 #1: ffff888056ebb028 (&sb->s_type->i_mutex_key#28){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff888056ebb028 (&sb->s_type->i_mutex_key#28){+.+.}-{3:3}, at: do_truncate+0x198/0x240 fs/open.c:63 #2: ffff888056ebae78 (&HFS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xfb/0x13f0 fs/hfs/extent.c:397 #3: ffff88807e33c0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x15b/0x1d0 fs/hfs/bfind.c:-1 stack backtrace: CPU: 1 PID: 5329 Comm: syz.0.227 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 hfs_extend_file+0xfb/0x13f0 fs/hfs/extent.c:397 hfs_bmap_reserve+0x103/0x420 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+0x39c/0x13f0 fs/hfs/extent.c:401 hfs_get_block+0x40f/0xc50 fs/hfs/extent.c:353 __block_write_begin_int+0x55d/0x1a80 fs/buffer.c:1991 __block_write_begin fs/buffer.c:2041 [inline] block_write_begin+0x96/0x1e0 fs/buffer.c:2102 cont_write_begin+0x5ea/0x800 fs/buffer.c:2456 hfs_write_begin+0x87/0xd0 fs/hfs/inode.c:58 cont_expand_zero fs/buffer.c:2383 [inline] cont_write_begin+0x2ad/0x800 fs/buffer.c:2446 hfs_write_begin+0x87/0xd0 fs/hfs/inode.c:58 hfs_file_truncate+0x1c0/0xa10 fs/hfs/extent.c:494 hfs_inode_setattr+0x4ab/0x6f0 fs/hfs/inode.c:659 notify_change+0xc74/0xf40 fs/attr.c:499 do_truncate+0x1ac/0x240 fs/open.c:65 vfs_truncate+0x262/0x2f0 fs/open.c:111 do_sys_truncate+0xf2/0x1c0 fs/open.c:134 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f9a8f99c799 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:00007f9a8dbf6028 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007f9a8fc15fa0 RCX: 00007f9a8f99c799 RDX: 0000000000000000 RSI: 0000000003000000 RDI: 0000200000000900 RBP: 00007f9a8fa32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9a8fc16038 R14: 00007f9a8fc15fa0 R15: 00007ffd6848c908