From 7103ae4d8b24b171f5321894a9bb045d018f0f40 Mon Sep 17 00:00:00 2001 From: Guillaume Nault Date: Mon, 22 Oct 2018 12:24:05 +0200 Subject: ipv6: fix IPv6 processing of sessions that only have only a link-local address Several modules assume that if ses->ipv6 is set, then ses->ipv6->addr_list contains at least one element. But this is not true if ipv6 was allocated by the pseudo ipdb backend of ipv6cp (ipv6cp_opt_intfid.c). That is, if the PPP session only has an automatic link-local address. This leads modules like pppd-compat and dhcpv6 to access invalid memory when trying to retrieve the IPv6 address of a PPP session. Signed-off-by: Guillaume Nault --- accel-pppd/lua/session.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'accel-pppd/lua') diff --git a/accel-pppd/lua/session.c b/accel-pppd/lua/session.c index 277b299f..bd98911b 100644 --- a/accel-pppd/lua/session.c +++ b/accel-pppd/lua/session.c @@ -197,7 +197,7 @@ static int session_ipv6(lua_State *L) if (!ses) return 0; - if (ses->ipv6) { + if (ses->ipv6 && !list_empty(&ses->ipv6->addr_list)) { a = list_entry(ses->ipv6->addr_list.next, typeof(*a), entry); if (a->prefix_len) { build_ip6_addr(a, ses->ipv6->peer_intf_id, &addr); -- cgit v1.2.3