net: drop write-only stack variable

Remove a write-only stack variable from unix_attach_fds(). This is a
left-over from the security fix in:

    commit 712f4aad406bb1ed67f3f98d04c044191f0ff593
    Author: willy tarreau <w@1wt.eu>
    Date:   Sun Jan 10 07:54:56 2016 +0100

        unix: properly account for FDs passed over unix sockets

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 49d5093..b374555 100644 (file)
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1534,7 +1534,6 @@ static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
 {
        int i;
        unsigned char max_level = 0;
-       int unix_sock_count = 0;
 
        if (too_many_unix_fds(current))
                return -ETOOMANYREFS;
@@ -1542,11 +1541,9 @@ static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
        for (i = scm->fp->count - 1; i >= 0; i--) {
                struct sock *sk = unix_get_socket(scm->fp->fp[i]);
 
-               if (sk) {
-                       unix_sock_count++;
+               if (sk)
                        max_level = max(max_level,
                                        unix_sk(sk)->recursion_level);
-               }
        }
        if (unlikely(max_level > MAX_RECURSION_LEVEL))
                return -ETOOMANYREFS;