recordmcount: Fix memory leaks in the uwrite function

[ Upstream commit fa359d068574d29e7d2f0fdd0ebe4c6a12b5cfb9 ]

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

Link: https://lkml.kernel.org/r/[email protected]

Signed-off-by: Hao Zeng <[email protected]>
Suggested-by: Steven Rostedt <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>

scripts/recordmcount.c

@@ -102,6 +102,7 @@ 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;
 
@@ -109,7 +110,10 @@ 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) {