channels: set error for new NULL pointer checks

Signed-off-by: Andreas Schneider <asn@cryptomilk.org>
(cherry picked from commit 8a83990c1603a051e74d5aa7a60445a7ef5021e4)

1 files changed, 50 insertions, 6 deletions

diff --git a/src/channels.c b/src/channels.c
index e5dbec5b..34ce069c 100644
--- a/src/channels.c
+++ b/src/channels.c
@@ -806,7 +806,18 @@ SSH_PACKET_CALLBACK(channel_rcv_request) {
  */
 int channel_default_bufferize(ssh_channel channel, void *data, int len,
     int is_stderr) {
-  ssh_session session = channel->session;
+  ssh_session session;
+
+  if(channel == NULL) {
+      return -1;
+  }
+
+  session = channel->session;
+
+  if(data == NULL) {
+      ssh_set_error_invalid(session, __FUNCTION__);
+      return -1;
+  }
 
   ssh_log(session, SSH_LOG_RARE,
       "placing %d bytes into channel buffer (stderr=%d)", len, is_stderr);
@@ -892,13 +903,24 @@ int ssh_channel_open_session(ssh_channel channel) {
  */
 int ssh_channel_open_forward(ssh_channel channel, const char *remotehost,
     int remoteport, const char *sourcehost, int localport) {
-  ssh_session session = channel->session;
+  ssh_session session;
   ssh_buffer payload = NULL;
   ssh_string str = NULL;
   int rc = SSH_ERROR;
 
   enter_function();
 
+  if (channel == NULL) {
+      return rc;
+  }
+
+  session = channel->session;
+
+  if(remotehost == NULL || sourcehost == NULL) {
+      ssh_set_error_invalid(session, __FUNCTION__);
+      return rc;
+  }
+
   payload = ssh_buffer_new();
   if (payload == NULL) {
     ssh_set_error_oom(session);
@@ -1081,15 +1103,28 @@ error:
 
 int channel_write_common(ssh_channel channel, const void *data,
     uint32_t len, int is_stderr) {
-  ssh_session session = channel->session;
+  ssh_session session;
   int origlen = len;
   size_t effectivelen;
-  /* handle the max packet len from remote side, be nice */
-  /* 10 bytes for the headers */
-  size_t maxpacketlen = channel->remote_maxpacket - 10;
+  size_t maxpacketlen;
+
+  if(channel == NULL || data == NULL) {
+      return -1;
+  }
+  session = channel->session;
+  if(data == NULL) {
+      ssh_set_error_invalid(session, __FUNCTION__);
+      return -1;
+  }
 
   enter_function();
 
+  /*
+   * Handle the max packet len from remote side, be nice
+   * 10 bytes for the headers
+   */
+  maxpacketlen = channel->remote_maxpacket - 10;
+
   if (channel->local_eof) {
     ssh_set_error(session, SSH_REQUEST_DENIED,
         "Can't write to channel %d:%d  after EOF was sent",
@@ -2824,6 +2859,15 @@ int ssh_channel_request_send_exit_signal(ssh_channel channel, const char *sig, i
   ssh_string tmp = NULL;
   int rc = SSH_ERROR;
 
+  if(channel == NULL) {
+      return rc;
+  }
+
+  if(sig == NULL || errmsg == NULL || lang == NULL) {
+      ssh_set_error_invalid(channel->session, __FUNCTION__);
+      return rc;
+  }
+
 #ifdef WITH_SSH1
   if (channel->version == 1) {
     return SSH_ERROR; // TODO: Add support for SSH-v1 if possible.