Code: void file_sb_list_add(struct file *file, struct super_block *sb)
{
	if (likely(!(file->f_mode & FMODE_WRITE)))
		return;
	if (!S_ISREG(file_inode(file)->i_mode))
		return;
	lg_local_lock(&files_lglock);
	__file_sb_list_add(file, sb);
	lg_local_unlock(&files_lglock);
}

Vulnerability Type: DoS 
CWE ID: CWE-17
Summary: The filesystem implementation in the Linux kernel before 3.13 performs certain operations on lists of files with an inappropriate locking approach, which allows local users to cause a denial of service (soft lockup or system crash) via unspecified use of Asynchronous I/O (AIO) operations.
Commit Message: get rid of s_files and files_lock

The only thing we need it for is alt-sysrq-r (emergency remount r/o)
and these days we can do just as well without going through the
list of files.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>