An invalid packet may not have set src and dst in packet descriptor.

Add a NULL check to prevent crash in pflog(4) introduced in previous
commit.
Reported-by: syzbot+c6d2f2ad34b822bce98a@syzkaller.appspotmail.com

diff --git a/sys/net/if_pflog.c b/sys/net/if_pflog.c
index 7b63991..a5bf67a 100644 (file)
--- a/sys/net/if_pflog.c
+++ b/sys/net/if_pflog.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_pflog.c,v 1.96 2021/01/20 13:40:15 bluhm Exp $     */
+/*     $OpenBSD: if_pflog.c,v 1.97 2021/01/20 23:25:19 bluhm Exp $     */
 /*
  * The authors of this code are John Ioannidis (ji@tla.org),
  * Angelos D. Keromytis (kermit@csd.uch.gr) and
@@ -232,12 +232,14 @@ pflog_packet(struct pf_pdesc *pd, u_int8_t reason, struct pf_rule *rm,
        hdr.dir = pd->dir;
        hdr.af = pd->af;
 
-       if (pd->af != pd->naf ||
-           pf_addr_compare(pd->src, &pd->nsaddr, pd->naf) != 0 ||
-           pf_addr_compare(pd->dst, &pd->ndaddr, pd->naf) != 0 ||
-           pd->osport != pd->nsport ||
-           pd->odport != pd->ndport) {
-               hdr.rewritten = 1;
+       if (pd->src != NULL && pd->dst != NULL) {
+               if (pd->af != pd->naf ||
+                   pf_addr_compare(pd->src, &pd->nsaddr, pd->naf) != 0 ||
+                   pf_addr_compare(pd->dst, &pd->ndaddr, pd->naf) != 0 ||
+                   pd->osport != pd->nsport ||
+                   pd->odport != pd->ndport) {
+                       hdr.rewritten = 1;
+               }
        }
        hdr.naf = pd->naf;
        pf_addrcpy(&hdr.saddr, &pd->nsaddr, pd->naf);