Doug / smarc-fsl-linux-kernel

Download as
Browse Code ยป

Commit 5aa8b572007c4bca1e6d3dd4c4820f1ae49d6bb2

Authored by Amerigo Wang
Committed by David S. Miller
1 parent 85457685e0
Exists in smarc-l5.0.0_1.0.0-ga and in 5 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga

pktgen: fix crash when generating IPv6 packets 

For IPv6, sizeof(struct ipv6hdr) = 40, thus the following
expression will result negative:

        datalen = pkt_dev->cur_pkt_size - 14 -
                  sizeof(struct ipv6hdr) - sizeof(struct udphdr) -
                  pkt_dev->pkt_overhead;

And,  the check "if (datalen < sizeof(struct pktgen_hdr))" will be
passed as "datalen" is promoted to unsigned, therefore will cause
a crash later.

This is a quick fix by checking if "datalen" is negative. The following
patch will increase the default value of 'min_pkt_size' for IPv6.

This bug should exist for a long time, so Cc -stable too.

Cc: <stable@vger.kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Showing 1 changed file with 1 additions and 1 deletions Side-by-side Diff

... ... @@ -2927,7 +2927,7 @@
2927 2927 sizeof(struct ipv6hdr) - sizeof(struct udphdr) -
2928 2928 pkt_dev->pkt_overhead;
2929 2929  
2930   - if (datalen < sizeof(struct pktgen_hdr)) {
  2930 + if (datalen < 0 || datalen < sizeof(struct pktgen_hdr)) {
2931 2931 datalen = sizeof(struct pktgen_hdr);
2932 2932 net_info_ratelimited("increased datalen to %d\n", datalen);
2933 2933 }