commit 3c0e8bc4a797d29b2152aebc6e687ddfa941160b
author philippe lhardy <pl@artisanlogiciel.net> Mon Apr 25 19:42:16 2022 +0200
committer Pauli <pauli@openssl.org> Fri May 06 11:16:21 2022 +1000
tree c05384f90061de530ffc5c425dbe34995db4922a
parent 50d1d92de9a4cf62723a3c1ea2f39501feea7d6e

fix for sslecho in demos echoing garbage #18165

- getline does set &txbufp content at return, make sure it can be done.
  - fixes warning 'passing argument 1 of ‘getline’ from incompatible pointer type'
- remove OPENSSL_free on non allocated fixed size array
  - fixes 'free(): invalid pointer'

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18177)

demos/sslecho/main.c

diff --git a/demos/sslecho/main.c b/demos/sslecho/main.c
index c6f087c..588158e 100644
--- a/demos/sslecho/main.c
+++ b/demos/sslecho/main.c
@@ -137,8 +137,9 @@
     int server_skt = -1;
     int client_skt = -1;
 
-    char txbuf[128];
-    size_t txcap = sizeof(txbuf);
+    /* used by getline relying on realloc, can't be statically allocated */
+    char *txbuf = NULL;
+    size_t txcap = 0;
     int txlen;
 
     char rxbuf[128];
@@ -286,11 +287,14 @@
             while (true) {
                 /* Get a line of input */
                 txlen = getline(&txbuf, &txcap, stdin);
+                /* Exit loop on error */
+                if (txlen < 0 || txbuf == NULL) {
+                    break;
+                }
                 /* Exit loop if just a carriage return */
                 if (txbuf[0] == '\n') {
                     break;
                 }
-
                 /* Send it to the server */
                 if ((result = SSL_write(ssl, txbuf, txlen)) <= 0) {
                     printf("Server closed connection\n");
@@ -331,8 +335,8 @@
     if (server_skt != -1)
         close(server_skt);
 
-    OPENSSL_free(txbuf);
-    OPENSSL_free(rxbuf);
+    if (txbuf != NULL && txcap > 0)
+        free(txbuf);
 
     printf("sslecho exiting\n");