recordmcount: Fix memory leaks in the uwrite function

Common realloc mistake: 'file_append' nulled but not freed upon failure

Link: https://lkml.kernel.org/r/20230426010527.703093-1-zenghao@kylinos.cn
Signed-off-by: Hao Zeng <zenghao@kylinos.cn>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c
index e302165..40ae6b2 100644 (file)
--- a/scripts/recordmcount.c
+++ b/scripts/recordmcount.c
@@ -110,6 +110,7 @@ static ssize_t uwrite(void const *const buf, size_t const count)
 {
        size_t cnt = count;
        off_t idx = 0;
+       void *p = NULL;
 
        file_updated = 1;
 
@@ -117,7 +118,10 @@ static ssize_t uwrite(void const *const buf, size_t const count)
                off_t aoffset = (file_ptr + count) - file_end;
 
                if (aoffset > file_append_size) {
-                       file_append = realloc(file_append, aoffset);
+                       p = realloc(file_append, aoffset);
+                       if (!p)
+                               free(file_append);
+                       file_append = p;
                        file_append_size = aoffset;
                }
                if (!file_append) {