[PATCH conntrackd 0/8] unsorted fixes

[PATCH conntrackd 0/8] unsorted fixes

[Pablo Neira Ayuso]

The following patchset contains a set of fixes for conntrackd as reported by
Paul Wouters.

Let me know if you have any concern with it, thank you.

Pablo Neira Ayuso (8):
  conntrackd: fix sanitization of expection attribute in the wire format
  conntrackd: NTA_MAX is also an invalid attribute
  conntrackd: fix leak in fork_process_new()
  conntrackd: fix descriptor leak in do_local_request()
  conntrackd: fix error handling in nfq_queue_cb()
  conntrackd: simplify branch in tcp_accept()
  conntrackd: use strncpy to set up the cache name
  conntrackd: missing break in expectation message parser function

 src/cache.c    |    5 +++--
 src/cthelper.c |   29 +++++++++++++++--------------
 src/local.c    |    9 ++++++---
 src/parse.c    |    8 +++++---
 src/process.c  |    2 ++
 src/tcp.c      |   12 +++++-------
 6 files changed, 36 insertions(+), 29 deletions(-)

-- 
1.7.10.4

[PATCH conntrackd 1/8] conntrackd: fix sanitization of expection attribute in the wire format

[Pablo Neira Ayuso]

The maximum number of attribute is NTA_EXP_MAX for expectation sync messages.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 src/parse.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/parse.c b/src/parse.c
index f3ec6ac..878e354 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -510,7 +510,7 @@ int msg2exp(struct nf_expect *exp, struct nethdr *net, size_t remain)
 		ATTR_NETWORK2HOST(attr);
 		if (attr->nta_len > len)
 			goto err;
-		if (attr->nta_attr > NTA_MAX)
+		if (attr->nta_attr >= NTA_EXP_MAX)
 			goto err;
 		if (attr->nta_len < NTA_LENGTH(0))
 			goto err;
-- 
1.7.10.4

[PATCH conntrackd 2/8] conntrackd: NTA_MAX is also an invalid attribute

[Pablo Neira Ayuso]

Otherwise this can result in an off-by-one array access.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 src/parse.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/parse.c b/src/parse.c
index 878e354..3ac4092 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -297,7 +297,7 @@ int msg2ct(struct nf_conntrack *ct, struct nethdr *net, size_t remain)
 			return -1;
 		if (attr->nta_len < NTA_LENGTH(0))
 			return -1;
-		if (attr->nta_attr > NTA_MAX)
+		if (attr->nta_attr >= NTA_MAX)
 			return -1;
 		if (h[attr->nta_attr].size &&
 		    attr->nta_len != h[attr->nta_attr].size)
-- 
1.7.10.4

[PATCH conntrackd 3/8] conntrackd: fix leak in fork_process_new()

[Pablo Neira Ayuso]

Release the child_process structure in case that fork() fails.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 src/process.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/process.c b/src/process.c
index 7f0a395..3ddad5f 100644
--- a/src/process.c
+++ b/src/process.c
@@ -48,6 +48,8 @@ int fork_process_new(int type, int flags, void (*cb)(void *data), void *data)
 
 	if (c->pid > 0)
 		list_add(&c->head, &process_list);
+	else
+		free(c);
 
 	return pid;
 }
-- 
1.7.10.4

[PATCH conntrackd 4/8] conntrackd: fix descriptor leak in do_local_request()

[Pablo Neira Ayuso]

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 src/local.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/local.c b/src/local.c
index 453799a..85e5180 100644
--- a/src/local.c
+++ b/src/local.c
@@ -147,11 +147,14 @@ int do_local_request(int request,
 
 	ret = send(fd, &request, sizeof(int), 0);
 	if (ret == -1)
-		return -1;
+		goto err1;
 
 	do_local_client_step(fd, step);
 
 	local_client_destroy(fd);
-	
+
 	return 0;
+err1:
+	local_client_destroy(fd);
+	return -1;
 }
-- 
1.7.10.4

[PATCH conntrackd 5/8] conntrackd: fix error handling in nfq_queue_cb()

[Pablo Neira Ayuso]

Make sure we have a clean exit on error, everything needs to be properly
released.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 src/cthelper.c |   29 +++++++++++++++--------------
 src/local.c    |    2 +-
 2 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/src/cthelper.c b/src/cthelper.c
index 6537515..54eb830 100644
--- a/src/cthelper.c
+++ b/src/cthelper.c
@@ -277,11 +277,11 @@ static int nfq_queue_cb(const struct nlmsghdr *nlh, void *data)
 
 	if (!attr[NFQA_PAYLOAD]) {
 		dlog(LOG_ERR, "packet with no payload");
-		goto err;
+		goto err1;
 	}
 	if (!attr[NFQA_CT] || !attr[NFQA_CT_INFO]) {
 		dlog(LOG_ERR, "no CT attached to this packet");
-		goto err;
+		goto err1;
 	}
 
 	pkt = mnl_attr_get_payload(attr[NFQA_PAYLOAD]);
@@ -292,22 +292,22 @@ static int nfq_queue_cb(const struct nlmsghdr *nlh, void *data)
 	queue_num = ntohs(nfg->res_id);
 
 	if (pkt_get(pkt, pktlen, ntohs(ph->hw_protocol), &protoff))
-		goto err;
+		goto err1;
 
 	ct = nfct_new();
 	if (ct == NULL)
-		goto err;
+		goto err1;
 
 	if (nfct_payload_parse(mnl_attr_get_payload(attr[NFQA_CT]),
 			       mnl_attr_get_payload_len(attr[NFQA_CT]),
 			       l3num, ct) < 0) {
 		dlog(LOG_ERR, "cannot convert message to CT");
-		goto err;
+		goto err2;
 	}
 
 	myct = calloc(1, sizeof(struct myct));
 	if (myct == NULL)
-		goto err;
+		goto err2;
 
 	myct->ct = ct;
 	ctinfo = ntohl(mnl_attr_get_u32(attr[NFQA_CT_INFO]));
@@ -315,15 +315,15 @@ static int nfq_queue_cb(const struct nlmsghdr *nlh, void *data)
 	/* XXX: 256 bytes enough for possible NAT mangling in helpers? */
 	pktb = pktb_alloc(AF_INET, pkt, pktlen, 256);
 	if (pktb == NULL)
-		goto err;
+		goto err3;
 
 	/* Misconfiguration: if no helper found, accept the packet. */
 	helper = helper_run(pktb, protoff, myct, ctinfo, queue_num, &verdict);
 	if (!helper)
-		goto err_pktb;
+		goto err4;
 
 	if (pkt_verdict_issue(helper, myct, queue_num, id, verdict, pktb) < 0)
-		goto err_pktb;
+		goto err4;
 
 	nfct_destroy(ct);
 	if (myct->exp != NULL)
@@ -333,18 +333,19 @@ static int nfq_queue_cb(const struct nlmsghdr *nlh, void *data)
 	free(myct);
 
 	return MNL_CB_OK;
-err_pktb:
+err4:
 	pktb_free(pktb);
-err:
+err3:
+	free(myct);
+err2:
+	nfct_destroy(ct);
+err1:
 	/* In case of error, we don't want to disrupt traffic. We accept all.
 	 * This is connection tracking after all. The policy is not to drop
 	 * packet unless we enter some inconsistent state.
 	 */
 	pkt_verdict_error(queue_num, id);
 
-	if (ct != NULL)
-		nfct_destroy(ct);
-
 	return MNL_CB_OK;
 }
 
diff --git a/src/local.c b/src/local.c
index 85e5180..3395b4c 100644
--- a/src/local.c
+++ b/src/local.c
@@ -77,7 +77,7 @@ int do_local_server_step(struct local_server *server, void *data,
 	int rfd;
 	struct sockaddr_un local;
 	socklen_t sin_size = sizeof(struct sockaddr_un);
-	
+
 	rfd = accept(server->fd, (struct sockaddr *) &local, &sin_size);
 	if (rfd == -1)
 		return -1;
-- 
1.7.10.4

[PATCH conntrackd 6/8] conntrackd: simplify branch in tcp_accept()

[Pablo Neira Ayuso]

The same code is executed regardless the reason why accept() has failed.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 src/tcp.c |   12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/src/tcp.c b/src/tcp.c
index af27c46..c8f2544 100644
--- a/src/tcp.c
+++ b/src/tcp.c
@@ -247,13 +247,11 @@ int tcp_accept(struct tcp_sock *m)
 	/* the other peer wants to connect ... */
 	ret = accept(m->fd, NULL, NULL);
 	if (ret == -1) {
-		if (errno != EAGAIN) {
-			/* unexpected error. Give us another try. */
-			m->state = TCP_SERVER_ACCEPTING;
-		} else {
-			/* waiting for new connections. */
-			m->state = TCP_SERVER_ACCEPTING;
-		}
+		/* unexpected error: Give us another try. Or we have hit
+ 		 * -EAGAIN, in that case we remain in the accepting connections
+		 * state.
+		 */
+		m->state = TCP_SERVER_ACCEPTING;
 	} else {
 		/* the peer finally got connected. */
 		if (fcntl(ret, F_SETFL, O_NONBLOCK) == -1) {
-- 
1.7.10.4

[PATCH conntrackd 7/8] conntrackd: use strncpy to set up the cache name

[Pablo Neira Ayuso]

This is not exposed, but use the strncpy() variant to calm down static code
validators.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 src/cache.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/cache.c b/src/cache.c
index 7c41e54..79a024f 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -34,7 +34,7 @@ struct cache_feature *cache_feature[CACHE_MAX_FEATURE] = {
 };
 
 struct cache *cache_create(const char *name, enum cache_type type,
-			   unsigned int features, 
+			   unsigned int features,
 			   struct cache_extra *extra,
 			   struct cache_ops *ops)
 {
@@ -53,7 +53,8 @@ struct cache *cache_create(const char *name, enum cache_type type,
 		return NULL;
 	memset(c, 0, sizeof(struct cache));
 
-	strcpy(c->name, name);
+	strncpy(c->name, name, CACHE_MAX_NAMELEN);
+	c->name[CACHE_MAX_NAMELEN - 1] = '\0';
 	c->type = type;
 
 	for (i = 0; i < CACHE_MAX_FEATURE; i++) {
-- 
1.7.10.4

[PATCH conntrackd 8/8] conntrackd: missing break in expectation message parser function

[Pablo Neira Ayuso]

Fortunately, the TLVs come in order in the message, however, if the order is
changed we'll incorrectly set up the expectation.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 src/parse.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/parse.c b/src/parse.c
index 3ac4092..919d36c 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -524,13 +524,15 @@ int msg2exp(struct nf_expect *exp, struct nethdr *net, size_t remain)
 			attr = NTA_NEXT(attr, len);
 			continue;
 		}
-		switch(exp_h[attr->nta_attr].exp_attr) {
+		switch (exp_h[attr->nta_attr].exp_attr) {
 		case ATTR_EXP_MASTER:
 			exp_h[attr->nta_attr].parse(master, attr->nta_attr,
 						    NTA_DATA(attr));
+			break;
 		case ATTR_EXP_EXPECTED:
 			exp_h[attr->nta_attr].parse(expected, attr->nta_attr,
 						    NTA_DATA(attr));
+			break;
 		case ATTR_EXP_MASK:
 			exp_h[attr->nta_attr].parse(mask, attr->nta_attr,
 						    NTA_DATA(attr));
-- 
1.7.10.4