[PATCH] tools/thermal: fix memory leak in realloc failure handling

[Kuan-Wei Chiu <visitorckw@gmail.com>]

In the previous code, there was a memory leak issue where the
previously allocated memory was not freed upon a failed realloc
operation. This patch addresses the problem by releasing the old memory
before setting the pointer to NULL in case of a realloc failure. This
ensures that memory is properly managed and avoids potential memory
leaks.

Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
---
 tools/thermal/lib/mainloop.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/tools/thermal/lib/mainloop.c b/tools/thermal/lib/mainloop.c
index 94cbbcbd1c14..6dcc4090d47e 100644
--- a/tools/thermal/lib/mainloop.c
+++ b/tools/thermal/lib/mainloop.c
@@ -62,9 +62,13 @@ int mainloop_add(int fd, mainloop_callback_t cb, void *data)
 	struct mainloop_data *md;
 
 	if (fd >= nrhandler) {
-		mds = realloc(mds, sizeof(*mds) * (fd + 1));
-		if (!mds)
+		struct mainloop_data **mds_tmp =
+			realloc(mds, sizeof(*mds) * (fd + 1));
+		if (!mds_tmp) {
+			free(mds);
 			return -1;
+		}
+		mds = mds_tmp;
 		nrhandler = fd + 1;
 	}
 
-- 
2.25.1