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/cli/show_sessions.c | 2 +- accel-pppd/extra/pppd_compat.c | 2 +- accel-pppd/ipv6/dhcpv6.c | 2 +- accel-pppd/lua/session.c | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-) (limited to 'accel-pppd') diff --git a/accel-pppd/cli/show_sessions.c b/accel-pppd/cli/show_sessions.c index 443b186..c725e05 100644 --- a/accel-pppd/cli/show_sessions.c +++ b/accel-pppd/cli/show_sessions.c @@ -414,7 +414,7 @@ static void print_ip6(struct ap_session *ses, char *buf) struct in6_addr addr; char *ptr; - if (!ses->ipv6) { + if (!ses->ipv6 || list_empty(&ses->ipv6->addr_list)) { *buf = 0; return; } diff --git a/accel-pppd/extra/pppd_compat.c b/accel-pppd/extra/pppd_compat.c index 318327e..7c23eca 100644 --- a/accel-pppd/extra/pppd_compat.c +++ b/accel-pppd/extra/pppd_compat.c @@ -622,7 +622,7 @@ static void fill_env(char **env, char *mem, struct pppd_compat_pd *pd) mem += write_sz + 1; ++n; - if (ses->ipv6) { + if (ses->ipv6 && !list_empty(&ses->ipv6->addr_list)) { ///FIXME only first address is passed to env struct ipv6db_addr_t *a = list_first_entry(&ses->ipv6->addr_list, typeof(*a), entry); diff --git a/accel-pppd/ipv6/dhcpv6.c b/accel-pppd/ipv6/dhcpv6.c index 84d36ca..36a5f15 100644 --- a/accel-pppd/ipv6/dhcpv6.c +++ b/accel-pppd/ipv6/dhcpv6.c @@ -69,7 +69,7 @@ static void ev_ses_started(struct ap_session *ses) int sock; int f = 1; - if (!ses->ipv6) + if (!ses->ipv6 || list_empty(&ses->ipv6->addr_list)) return; a = list_entry(ses->ipv6->addr_list.next, typeof(*a), entry); diff --git a/accel-pppd/lua/session.c b/accel-pppd/lua/session.c index 277b299..bd98911 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