Move null check up and simplify process_escapes. Based on Coverity CID

291863 which points out we check the channel pointer for NULLness after
dereferencing it.  Move this to the start of the function, and while
there simplify initialization of efc a bit.  ok djm@

diff --git a/usr.bin/ssh/clientloop.c b/usr.bin/ssh/clientloop.c
index 989d749..67a9f17 100644 (file)
--- a/usr.bin/ssh/clientloop.c
+++ b/usr.bin/ssh/clientloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: clientloop.c,v 1.391 2023/03/31 04:04:15 djm Exp $ */
+/* $OpenBSD: clientloop.c,v 1.392 2023/04/03 08:10:54 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -996,14 +996,12 @@ process_escapes(struct ssh *ssh, Channel *c,
        u_int i;
        u_char ch;
        char *s;
-       struct escape_filter_ctx *efc = c->filter_ctx == NULL ?
-           NULL : (struct escape_filter_ctx *)c->filter_ctx;
+       struct escape_filter_ctx *efc;
 
-       if (c->filter_ctx == NULL)
+       if (c == NULL || c->filter_ctx == NULL || len <= 0)
                return 0;
 
-       if (len <= 0)
-               return (0);
+       efc = (struct escape_filter_ctx *)c->filter_ctx;
 
        for (i = 0; i < (u_int)len; i++) {
                /* Get one character at a time. */
@@ -1100,7 +1098,7 @@ process_escapes(struct ssh *ssh, Channel *c,
                                continue;
 
                        case '&':
-                               if (c && c->ctl_chan != -1)
+                               if (c->ctl_chan != -1)
                                        goto noescape;
                                /*
                                 * Detach the program (continue to serve