github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-21 05:18:45 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

pktgen: fix crash when generating IPv6 packets

Browse Source 
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>
This commit is contained in:
Amerigo Wang 2012-10-09 17:48:16 +00:00 committed by David S. Miller
parent 85457685e0
commit 5aa8b57200
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
net/core/pktgen.c
View File

@ -2927,7 +2927,7 @@ static struct sk_buff *fill_packet_ipv6(struct net_device *odev,
sizeof(struct ipv6hdr) - sizeof(struct udphdr) -
pkt_dev->pkt_overhead;
if (datalen < sizeof(struct pktgen_hdr)) {
if (datalen < 0 || datalen < sizeof(struct pktgen_hdr)) {
datalen = sizeof(struct pktgen_hdr);
net_info_ratelimited("increased datalen to %d\n", datalen);
}