From: Zhengchuan Liang struct ip6t_opts stores at most IP6T_OPTS_OPTSNR option descriptors, but hbh_mt6_check() does not reject larger optsnr values supplied from userspace. Validate optsnr in the rule setup path so only match data that fits the fixed-size opts array can be installed. This follows the existing xtables pattern of rejecting invalid user-provided counts in checkentry() and keeps the packet matching path unchanged. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Signed-off-by: Zhengchuan Liang Signed-off-by: Ren Wei --- net/ipv6/netfilter/ip6t_hbh.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/ipv6/netfilter/ip6t_hbh.c b/net/ipv6/netfilter/ip6t_hbh.c index e7a3fb9355ee..450dd53846a2 100644 --- a/net/ipv6/netfilter/ip6t_hbh.c +++ b/net/ipv6/netfilter/ip6t_hbh.c @@ -168,6 +168,10 @@ static int hbh_mt6_check(const struct xt_mtchk_param *par) pr_debug("unknown flags %X\n", optsinfo->invflags); return -EINVAL; } + if (optsinfo->optsnr > IP6T_OPTS_OPTSNR) { + pr_debug("too many supported opts specified\n"); + return -EINVAL; + } if (optsinfo->flags & IP6T_OPTS_NSTRICT) { pr_debug("Not strict - not implemented"); -- 2.47.3