patch 9.1.0739: [security]: use-after-free in ex_getln.c

Problem:  [security]: use-after-free in ex_getln.c
Solution: free pointer p a bit later (John Marriott)

closes: #15712

Signed-off-by: John Marriott <basilisk@internode.on.net>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/ex_getln.c

@@ -3330,7 +3330,6 @@ realloc_cmdbuff(int len)
     // there, thus copy up to the NUL and add a NUL.
     mch_memmove(ccline.cmdbuff, p, (size_t)ccline.cmdlen);
     ccline.cmdbuff[ccline.cmdlen] = NUL;
-    vim_free(p);
 
     if (ccline.xpc != NULL
 	    && ccline.xpc->xp_pattern != NULL
@@ -3345,6 +3344,8 @@ realloc_cmdbuff(int len)
 	    ccline.xpc->xp_pattern = ccline.cmdbuff + i;
     }
 
+    vim_free(p);
+
     return OK;
 }
 

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    739,
 /**/
     738,
 /**/