Re: [PATCH] s390/mm: Fix memory leak in add_marker() when kvrealloc fails

On Mon, Oct 27, 2025 at 07:53:25PM +0800, 林妙倩 wrote:

...

Care to send a new version?

I'm not sure if I can make it right. Do you think this way can fix the leak correctly? Thanks.

static int add_marker(unsigned long start, unsigned long end, const char *name)
 {
-       size_t oldsize, newsize;
-
-       oldsize = markers_cnt * sizeof(*markers);
-       newsize = oldsize + 2 * sizeof(*markers);
-       if (!oldsize)
-               markers = kvmalloc(newsize, GFP_KERNEL);
-       else
-               markers = kvrealloc(markers, newsize, GFP_KERNEL);
-       if (!markers)
-               goto error;
+       struct addr_marker *new_markers;
+       size_t newsize;
+
+       newsize = (markers_cnt + 2) * sizeof(*markers);
+       new_markers = kvrealloc(markers, newsize, GFP_KERNEL);
+       if (!new_markers)
+               return -ENOMEM;
+
+       markers = new_markers;
        markers[markers_cnt].is_start = 1;
        markers[markers_cnt].start_address = start;
        markers[markers_cnt].size = end - start;
@@ -312,9 +311,6 @@ static int add_marker(unsigned long start,
unsigned long end, const char *name)
        markers[markers_cnt].name = name;
        markers_cnt++;
        return 0;
-error:
-       markers_cnt = 0;
-       return -ENOMEM;
 }

Not exactly what I had in mind, but this looks good too. Could you send a proper second version of your patch, please?

Thanks!