syzbot

REISERFS (device loop4): Using tea hash to sort names
REISERFS (device loop4): Created .reiserfs_priv - reserved for xattr storage.
======================================================
WARNING: possible circular locking dependency detected
6.6.99-syzkaller #0 Not tainted
------------------------------------------------------
syz.4.35/6215 is trying to acquire lock:
ffff888141f85090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x79/0xd0 fs/reiserfs/lock.c:27

but task is already holding lock:
ffff88805c2f0990 (&type->i_mutex_dir_key#10/3){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
ffff88805c2f0990 (&type->i_mutex_dir_key#10/3){+.+.}-{3:3}, at: open_xa_root fs/reiserfs/xattr.c:128 [inline]
ffff88805c2f0990 (&type->i_mutex_dir_key#10/3){+.+.}-{3:3}, at: open_xa_dir+0x122/0x6f0 fs/reiserfs/xattr.c:153

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&type->i_mutex_dir_key#10/3){+.+.}-{3:3}:
       down_write_nested+0x9e/0x1f0 kernel/locking/rwsem.c:1689
       inode_lock_nested include/linux/fs.h:839 [inline]
       open_xa_root fs/reiserfs/xattr.c:128 [inline]
       open_xa_dir+0x122/0x6f0 fs/reiserfs/xattr.c:153
       reiserfs_for_each_xattr+0x17b/0x960 fs/reiserfs/xattr.c:253
       reiserfs_delete_xattrs+0x20/0x90 fs/reiserfs/xattr.c:365
       reiserfs_evict_inode+0x225/0x490 fs/reiserfs/inode.c:53
       evict+0x486/0x870 fs/inode.c:705
       reiserfs_new_inode+0x5cc/0x17d0 fs/reiserfs/inode.c:2152
       reiserfs_mkdir+0x55b/0x970 fs/reiserfs/namei.c:843
       vfs_mkdir+0x296/0x440 fs/namei.c:4113
       do_mkdirat+0x1d4/0x440 fs/namei.c:4136
       __do_sys_mkdirat fs/namei.c:4151 [inline]
       __se_sys_mkdirat fs/namei.c:4149 [inline]
       __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4149
       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 (&sbi->lock){+.+.}-{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
       reiserfs_write_lock+0x79/0xd0 fs/reiserfs/lock.c:27
       reiserfs_mkdir+0x310/0x970 fs/reiserfs/namei.c:829
       xattr_mkdir fs/reiserfs/xattr.c:77 [inline]
       open_xa_root fs/reiserfs/xattr.c:137 [inline]
       open_xa_dir+0x31a/0x6f0 fs/reiserfs/xattr.c:153
       xattr_lookup+0x22/0x2a0 fs/reiserfs/xattr.c:396
       reiserfs_xattr_set_handle+0xf9/0xd40 fs/reiserfs/xattr.c:535
       reiserfs_xattr_set+0x439/0x550 fs/reiserfs/xattr.c:635
       __vfs_setxattr+0x431/0x470 fs/xattr.c:201
       __vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235
       vfs_setxattr+0x16c/0x2f0 fs/xattr.c:322
       do_setxattr fs/xattr.c:630 [inline]
       path_setxattr+0x362/0x550 fs/xattr.c:659
       __do_sys_lsetxattr fs/xattr.c:684 [inline]
       __se_sys_lsetxattr fs/xattr.c:680 [inline]
       __x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:680
       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(&type->i_mutex_dir_key#10/3);
                               lock(&sbi->lock);
                               lock(&type->i_mutex_dir_key#10/3);
  lock(&sbi->lock);

 *** DEADLOCK ***

3 locks held by syz.4.35/6215:
 #0: ffff88807c556418 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:403
 #1: ffff88805c2f1030 (&sb->s_type->i_mutex_key#26){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #1: ffff88805c2f1030 (&sb->s_type->i_mutex_key#26){+.+.}-{3:3}, at: vfs_setxattr+0x145/0x2f0 fs/xattr.c:321
 #2: ffff88805c2f0990 (&type->i_mutex_dir_key#10/3){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
 #2: ffff88805c2f0990 (&type->i_mutex_dir_key#10/3){+.+.}-{3:3}, at: open_xa_root fs/reiserfs/xattr.c:128 [inline]
 #2: ffff88805c2f0990 (&type->i_mutex_dir_key#10/3){+.+.}-{3:3}, at: open_xa_dir+0x122/0x6f0 fs/reiserfs/xattr.c:153

stack backtrace:
CPU: 0 PID: 6215 Comm: syz.4.35 Not tainted 6.6.99-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 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
 reiserfs_write_lock+0x79/0xd0 fs/reiserfs/lock.c:27
 reiserfs_mkdir+0x310/0x970 fs/reiserfs/namei.c:829
 xattr_mkdir fs/reiserfs/xattr.c:77 [inline]
 open_xa_root fs/reiserfs/xattr.c:137 [inline]
 open_xa_dir+0x31a/0x6f0 fs/reiserfs/xattr.c:153
 xattr_lookup+0x22/0x2a0 fs/reiserfs/xattr.c:396
 reiserfs_xattr_set_handle+0xf9/0xd40 fs/reiserfs/xattr.c:535
 reiserfs_xattr_set+0x439/0x550 fs/reiserfs/xattr.c:635
 __vfs_setxattr+0x431/0x470 fs/xattr.c:201
 __vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235
 vfs_setxattr+0x16c/0x2f0 fs/xattr.c:322
 do_setxattr fs/xattr.c:630 [inline]
 path_setxattr+0x362/0x550 fs/xattr.c:659
 __do_sys_lsetxattr fs/xattr.c:684 [inline]
 __se_sys_lsetxattr fs/xattr.c:680 [inline]
 __x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:680
 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: 0033:0x7f4fd458e9a9
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:00007f4fd540c038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007f4fd47b5fa0 RCX: 00007f4fd458e9a9
RDX: 0000200000000400 RSI: 00002000000000c0 RDI: 0000200000000080
RBP: 00007f4fd4610d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000104 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f4fd47b5fa0 R15: 00007ffc36ff7308
 </TASK>