[NETFILTER]: nf_conntrack_h323: add checking of out-of-range on choices' index values

Choices' index values may be out of range while still encoded in the fixed
length bit-field. This bug may cause access to undefined types (NULL
pointers) and thus crashes (Reported by Zhongling Wen).

This patch also adds checking of decode flag when decoding SEQUENCEs.

Signed-off-by: Jing Min Zhao <zhaojingmin@vivecode.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 1 deletions

diff --git a/net/netfilter/nf_conntrack_h323_asn1.c b/net/netfilter/nf_conntrack_h323_asn1.c
index f6fad713d484..6b7eaa019d4c 100644
--- a/net/netfilter/nf_conntrack_h323_asn1.c
+++ b/net/netfilter/nf_conntrack_h323_asn1.c
@@ -518,7 +518,7 @@ int decode_seq(bitstr_t * bs, field_t * f, char *base, int level)
                         CHECK_BOUND(bs, 2);
                         len = get_len(bs);
                         CHECK_BOUND(bs, len);
-                        if (!base) {
+                        if (!base || !(son->attr & DECODE)) {
                                 PRINT("%*.s%s\n", (level + 1) * TAB_SIZE,
                                       " ", son->name);
                                 bs->cur += len;
@@ -704,6 +704,8 @@ int decode_choice(bitstr_t * bs, field_t * f, char *base, int level)
         } else {
                 ext = 0;
                 type = get_bits(bs, f->sz);
+                if (type >= f->lb)
+                        return H323_ERROR_RANGE;
         }
 
         /* Write Type */