From be99c62ac7e7af514e4b13f83c891a3cccefaa48 Mon Sep 17 00:00:00 2001 From: Edward Adam Davis Date: Tue, 16 Sep 2025 13:50:13 +0800 Subject: [PATCH] ntfs3: init run lock for extend inode After setting the inode mode of $Extend to a regular file, executing the truncate system call will enter the do_truncate() routine, causing the run_lock uninitialized error reported by syzbot. Prior to patch 4e8011ffec79, if the inode mode of $Extend was not set to a regular file, the do_truncate() routine would not be entered. Add the run_lock initialization when loading $Extend. syzbot reported: INFO: trying to register non-static key. Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 assign_lock_key+0x133/0x150 kernel/locking/lockdep.c:984 register_lock_class+0x105/0x320 kernel/locking/lockdep.c:1299 __lock_acquire+0x99/0xd20 kernel/locking/lockdep.c:5112 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1590 ntfs_set_size+0x140/0x200 fs/ntfs3/inode.c:860 ntfs_extend+0x1d9/0x970 fs/ntfs3/file.c:387 ntfs_setattr+0x2e8/0xbe0 fs/ntfs3/file.c:808 Fixes: 4e8011ffec79 ("ntfs3: pretend $Extend records as regular files") Reported-by: syzbot+bdeb22a4b9a09ab9aa45@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=bdeb22a4b9a09ab9aa45 Tested-by: syzbot+bdeb22a4b9a09ab9aa45@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis Signed-off-by: Konstantin Komarov --- fs/ntfs3/inode.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c index 439078106cc6..b0c557a6c115 100644 --- a/fs/ntfs3/inode.c +++ b/fs/ntfs3/inode.c @@ -472,6 +472,7 @@ static struct inode *ntfs_read_mft(struct inode *inode, /* Records in $Extend are not a files or general directories. */ inode->i_op = &ntfs_file_inode_operations; mode = S_IFREG; + init_rwsem(&ni->file.run_lock); } else { err = -EINVAL; goto out;