Do not drop packet when CSeq is 0 as 0 is also a valid value for CSeq.
In order to do so, we replace obsolete simple_strtoul() which
returns 0 on error by kstrtouint(). As kstrtouint() requires a
NULL terminated string, we need to use a temporary buffer
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
net/netfilter/nf_conntrack_sip.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index f72ba55..e770477 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -1368,6 +1368,7 @@ static int process_sip_response(struct sk_buff *skb, unsigned int protoff,
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
unsigned int matchoff, matchlen, matchend;
unsigned int code, cseq, i;
+ char buf[21];
if (*datalen < strlen("SIP/2.0 200"))
return NF_ACCEPT;
@@ -1382,8 +1383,13 @@ static int process_sip_response(struct sk_buff *skb, unsigned int protoff,
nf_ct_helper_log(skb, ct, "cannot parse cseq");
return NF_DROP;
}
- cseq = simple_strtoul(*dptr + matchoff, NULL, 10);
- if (!cseq) {
+ if (matchlen > sizeof(buf) - 1) {
+ nf_ct_helper_log(skb, ct, "cannot parse cseq (too big)");
+ return NF_DROP;
+ }
+ memcpy(buf, *dptr + matchoff, matchlen);
+ buf[matchlen] = 0;
+ if (kstrtouint(buf, 10, &cseq)) {
nf_ct_helper_log(skb, ct, "cannot get cseq");
return NF_DROP;
}
@@ -1432,6 +1438,7 @@ static int process_sip_request(struct sk_buff *skb, unsigned int protoff,
for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) {
const struct sip_handler *handler;
+ char buf[21];
handler = &sip_handlers[i];
if (handler->request == NULL)
@@ -1445,8 +1452,13 @@ static int process_sip_request(struct sk_buff *skb, unsigned int protoff,
nf_ct_helper_log(skb, ct, "cannot parse cseq");
return NF_DROP;
}
- cseq = simple_strtoul(*dptr + matchoff, NULL, 10);
- if (!cseq) {
+ if (matchlen > sizeof(buf) - 1) {
+ nf_ct_helper_log(skb, ct, "cannot parse cseq(too big)");
+ return NF_DROP;
+ }
+ memcpy(buf, *dptr + matchoff, matchlen);
+ buf[matchlen] = 0;
+ if (kstrtouint(buf, 10, &cseq)) {
nf_ct_helper_log(skb, ct, "cannot get cseq");
return NF_DROP;
}
--
2.1.0
--
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