netfilter: nf_conntrack_tcp: fix unaligned memory access in tcp_sack
This patch fixes an unaligned memory access in tcp_sack while reading
sequence numbers from TCP selective acknowledgement options. Prior to
applying this patch, upstream linux-2.6.27.20 was occasionally
generating messages like this on my sparc64 system:
[54678.532071] Kernel unaligned access at TPC[6b17d4] tcp_packet+0xcd4/0xd00
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index f3fd154..56ac4ee 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -15,6 +15,7 @@
#include <linux/skbuff.h>
#include <linux/ipv6.h>
#include <net/ip6_checksum.h>
+#include <asm/unaligned.h>
#include <net/tcp.h>
@@ -466,7 +467,7 @@
for (i = 0;
i < (opsize - TCPOLEN_SACK_BASE);
i += TCPOLEN_SACK_PERBLOCK) {
- tmp = ntohl(*((__be32 *)(ptr+i)+1));
+ tmp = get_unaligned_be32((__be32 *)(ptr+i)+1);
if (after(tmp, *sack))
*sack = tmp;