Coverity: Fix bugs in bitmap2rangestr().

awlauria · awlauria · commit 3735f7945e35 · 2021-11-22T08:59:15.000-05:00
Make sure snprintf() doesn't overflow the buffer.

Signed-off-by: Austen Lauria &lt;awlauria@us.ibm.com&gt;
diff --git a/ompi/mpiext/affinity/c/mpiext_affinity_str.c b/ompi/mpiext/affinity/c/mpiext_affinity_str.c
@@ -206,7 +206,8 @@ static char *bitmap2rangestr(int bitmap)
                 } else {
                     snprintf(tmp, stmp, "%d-%d", range_start, range_end);
                 }
-                snprintf(ret + strlen(ret), BUFSIZ, "%s", tmp);
+                size_t ret_len = strlen(ret);
+                snprintf(ret + ret_len, BUFSIZ - ret_len, "%s", tmp);
 
                 range_start = -999;
             }
@@ -233,7 +234,8 @@ static char *bitmap2rangestr(int bitmap)
         } else {
             snprintf(tmp, stmp, "%d-%d", range_start, range_end);
         }
-        snprintf(ret + strlen(ret), BUFSIZ, "%s",  tmp);
+        size_t ret_len = strlen(ret);
+        snprintf(ret + ret_len, BUFSIZ - ret_len, "%s",  tmp);
     }
 
     return ret;

Original file line number	Diff line number	Diff line change
`@@ -206,7 +206,8 @@ static char *bitmap2rangestr(int bitmap)`
`206`	`206`	`} else {`
`207`	`207`	`snprintf(tmp, stmp, "%d-%d", range_start, range_end);`
`208`	`208`	`}`
`209`		`- snprintf(ret + strlen(ret), BUFSIZ, "%s", tmp);`
	`209`	`+ size_t ret_len = strlen(ret);`
	`210`	`+ snprintf(ret + ret_len, BUFSIZ - ret_len, "%s", tmp);`
`210`	`211`
`211`	`212`	`range_start = -999;`
`212`	`213`	`}`
`@@ -233,7 +234,8 @@ static char *bitmap2rangestr(int bitmap)`
`233`	`234`	`} else {`
`234`	`235`	`snprintf(tmp, stmp, "%d-%d", range_start, range_end);`
`235`	`236`	`}`
`236`		`- snprintf(ret + strlen(ret), BUFSIZ, "%s", tmp);`
	`237`	`+ size_t ret_len = strlen(ret);`
	`238`	`+ snprintf(ret + ret_len, BUFSIZ - ret_len, "%s", tmp);`
`237`	`239`	`}`
`238`	`240`
`239`	`241`	`return ret;`