Messages in this thread | | | From | Linus Torvalds <> | Date | Mon, 23 Sep 2019 14:35:28 -0700 | Subject | Re: [GIT PULL] Smack patches for v5.4 - retry |
| |
On Mon, Sep 23, 2019 at 1:14 PM Casey Schaufler <casey@schaufler-ca.com> wrote: > > Thank for the instruction. I think this is correct.
Looks fine, pulled.
That said, when I look closer:
> Jia-Ju Bai (1): > security: smack: Fix possible null-pointer dereferences in smack_socket_sock_rcv_skb()
This one seems wrong.
Not seriously so, but the quoting the logic from the commit:
In smack_socket_sock_rcv_skb(), there is an if statement on line 3920 to check whether skb is NULL:
if (skb && skb->secmark != 0)
This check indicates skb can be NULL in some cases.
and the fact is, skb _cannot_ be NULL, because when you test the security of receiving an skb, you by definition always have an skb.
There is one single place that calls security_sock_rcv_skb(), and it very much has a real skb.
So instead of adding a _new_ test for skb being NULL, the old test for a NULL skb should just have been removed. It really doesn't make any sense to have a NULL skb in that path - if some memory allocation had failed on the receive path, that just means that the receive is never done, it doesn't mean that you'd test a NULL skb for security policy violations.
Anyway, it's pulled, but I think somebody should have checked and thought about the automated tool reports a bit more..
Linus
| |