From: Ludwig Nussel <ludwig.nussel@suse.de>
Date: Wed, 19 May 2010 13:43:44 +0000 (+0200)
Subject: socket: ignore packet if FIONREAD returns zero
X-Git-Url: https://git.meshlink.io/?a=commitdiff_plain;h=2b2844b10d7b7e5c97f9c667d664d9418bb7769a;p=catta

socket: ignore packet if FIONREAD returns zero

zero size is reported for corrupt packets. recvmsg() later could
nevertheless get data from a good packet that followed the bad one.
So get out early to avoid hitting an assertion.
---

diff --git a/avahi-core/socket.c b/avahi-core/socket.c
index 4146d5a..f9b90a2 100644
--- a/avahi-core/socket.c
+++ b/avahi-core/socket.c
@@ -652,6 +652,10 @@ AvahiDnsPacket *avahi_recv_dns_packet_ipv4(
         goto fail;
     }
 
+    /* For corrupt packets FIONREAD returns zero size (See rhbz #607297) */
+    if (!ms)
+        goto fail;
+
     p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE);
 
     io.iov_base = AVAHI_DNS_PACKET_DATA(p);
@@ -805,6 +809,10 @@ AvahiDnsPacket *avahi_recv_dns_packet_ipv6(
         goto fail;
     }
 
+    /* For corrupt packets FIONREAD returns zero size (See rhbz #607297) */
+    if (!ms)
+        goto fail;
+
     p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE);
 
     io.iov_base = AVAHI_DNS_PACKET_DATA(p);