Merge pull request #2133 from rlaager/fix-check_ssh-buffer-overflow

Fix check ssh buffer overflow

1 files changed, 6 insertions, 4 deletions

diff --git a/plugins/check_ssh.c b/plugins/check_ssh.c
index 9d0d7cde..2c76fa84 100644
--- a/plugins/check_ssh.c
+++ b/plugins/check_ssh.c
@@ -255,7 +255,7 @@ int ssh_connect(mp_check *overall, char *haddr, int hport, char *desired_remote_
                         byte_offset = 0;
 
                         char *index = NULL;
-                        unsigned long len = 0;
+                        size_t len = 0;
                         while ((index = strchr(output + byte_offset, '\n')) != NULL) {
                                 /*Partition the buffer so that this line is a separate string,
                                  * by replacing the newline with NUL*/
@@ -273,12 +273,14 @@ int ssh_connect(mp_check *overall, char *haddr, int hport, char *desired_remote_
                         }
 
                         if (version_control_string == NULL) {
-                                /* move unconsumed data to beginning of buffer, null rest */
-                                memmove((void *)output, (void *)(output + byte_offset + 1), BUFF_SZ - len + 1);
-                                memset(output + byte_offset + 1, 0, BUFF_SZ - byte_offset + 1);
+                                /* move unconsumed data to beginning of buffer */
+                                memmove((void *)output, (void *)(output + byte_offset), BUFF_SZ - byte_offset);
 
                                 /*start reading from end of current line chunk on next recv*/
                                 byte_offset = strlen(output);
+
+                                /* NUL the rest of the buffer */
+                                memset(output + byte_offset, 0, BUFF_SZ - byte_offset);
                         }
                 } else {
                         byte_offset += recv_ret;