• David Howells's avatar
    KEYS: Change the name of the dead type to ".dead" to prevent user access · b2dd90e8
    David Howells authored
    commit c1644fe0 upstream.
    
    This fixes CVE-2017-6951.
    
    Userspace should not be able to do things with the "dead" key type as it
    doesn't have some of the helper functions set upon it that the kernel
    needs.  Attempting to use it may cause the kernel to crash.
    
    Fix this by changing the name of the type to ".dead" so that it's rejected
    up front on userspace syscalls by key_get_type_from_user().
    
    Though this doesn't seem to affect recent kernels, it does affect older
    ones, certainly those prior to:
    
    	commit c06cfb08
    	Author: David Howells <dhowells@redhat.com>
    	Date:   Tue Sep 16 17:36:06 2014 +0100
    	KEYS: Remove key_type::match in favour of overriding default by match_preparse
    
    which went in before 3.18-rc1.
    Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    b2dd90e8
gc.c 9.73 KB