[NETFILTER]: SIP conntrack: fix skipping over user info in SIP headers

When trying to skip over the username in the Contact header, stop at the
end of the line if no @ is found to avoid mangling following headers.
We don't need to worry about continuation lines because we search inside
a SIP URI.

Fixes Netfilter Bugzilla #532.

Signed-off-by: Lars Immisch <lars@ibp.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 14 insertions, 2 deletions

diff --git a/net/ipv4/netfilter/ip_conntrack_sip.c b/net/ipv4/netfilter/ip_conntrack_sip.c
index 3a26d63eed88..571d27e20910 100644
--- a/net/ipv4/netfilter/ip_conntrack_sip.c
+++ b/net/ipv4/netfilter/ip_conntrack_sip.c
@@ -283,8 +283,14 @@ static int skp_epaddr_len(const char *dptr, const char *limit, int *shift)
 {
         int s = *shift;
 
-        for (; dptr <= limit && *dptr != '@'; dptr++)
+        /* Search for @, but stop at the end of the line.
+         * We are inside a sip: URI, so we don't need to worry about
+         * continuation lines. */
+        while (dptr <= limit &&
+               *dptr != '@' && *dptr != '\r' && *dptr != '\n') {
                 (*shift)++;
+                dptr++;
+        }
 
         if (*dptr == '@') {
                 dptr++;
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index eb2a2411f97b..c93fb37a54fc 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -303,8 +303,14 @@ static int skp_epaddr_len(struct nf_conn *ct, const char *dptr,
 {
         int s = *shift;
 
-        for (; dptr <= limit && *dptr != '@'; dptr++)
+        /* Search for @, but stop at the end of the line.
+         * We are inside a sip: URI, so we don't need to worry about
+         * continuation lines. */
+        while (dptr <= limit &&
+               *dptr != '@' && *dptr != '\r' && *dptr != '\n') {
                 (*shift)++;
+                dptr++;
+        }
 
         if (*dptr == '@') {
                 dptr++;