From 2d01764089beffda717a705d227778bb1560441a Mon Sep 17 00:00:00 2001 From: gnn Date: Wed, 23 Nov 2016 13:14:19 +0000 Subject: [PATCH] MFC: 307541 Limit the number of mbufs that can be allocated for IPV6_2292PKTOPTIONS (and IPV6_PKTOPTIONS). PR: 100219 Submitted by: Joseph Kong --- sys/netinet6/ip6_output.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/sys/netinet6/ip6_output.c b/sys/netinet6/ip6_output.c index 2b0e50d7be3..2674f8a06a0 100644 --- a/sys/netinet6/ip6_output.c +++ b/sys/netinet6/ip6_output.c @@ -1398,6 +1398,15 @@ ip6_ctloutput(struct socket *so, struct sockopt *sopt) int retval; #endif +/* + * Don't use more than a quarter of mbuf clusters. N.B.: + * nmbclusters is an int, but nmbclusters * MCLBYTES may overflow + * on LP64 architectures, so cast to u_long to avoid undefined + * behavior. ILP32 architectures cannot have nmbclusters + * large enough to overflow for other reasons. + */ +#define IPV6_PKTOPTIONS_MBUF_LIMIT ((u_long)nmbclusters * MCLBYTES / 4) + level = sopt->sopt_level; op = sopt->sopt_dir; optname = sopt->sopt_name; @@ -1453,6 +1462,12 @@ ip6_ctloutput(struct socket *so, struct sockopt *sopt) { struct mbuf *m; + if (optlen > IPV6_PKTOPTIONS_MBUF_LIMIT) { + printf("ip6_ctloutput: mbuf limit hit\n"); + error = ENOBUFS; + break; + } + error = soopt_getm(sopt, &m); /* XXX */ if (error != 0) break; -- 2.45.0