[PATCH] mm: transhuge-stress: fix potential memory leak on realloc failure

[Haofeng Li]

From: Haofeng Li <lihaof...@kylinos.cn>

When realloc() fails in transhuge-stress test, the original code
exits immediately without freeing the previously allocated memory,
causing a memory leak. This patch introduces a temporary pointer
to hold the realloc result, ensuring proper cleanup by freeing
the original map before exiting on allocation failure.

Signed-off-by: Haofeng Li <lihaof...@kylinos.cn>
---
 tools/testing/selftests/mm/transhuge-stress.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/mm/transhuge-stress.c 
b/tools/testing/selftests/mm/transhuge-stress.c
index 68201192e37c..cbe86c5b8de0 100644
--- a/tools/testing/selftests/mm/transhuge-stress.c
+++ b/tools/testing/selftests/mm/transhuge-stress.c
@@ -30,7 +30,7 @@ int main(int argc, char **argv)
        int i = 0;
        char *name = NULL;
        double s;
-       uint8_t *map;
+       uint8_t *map, *map_tmp;
        size_t map_len;
        int pagemap_fd;
        int duration = 0;
@@ -107,9 +107,12 @@ int main(int argc, char **argv)
 
                                nr_succeed++;
                                if (idx >= map_len) {
-                                       map = realloc(map, idx + 1);
-                                       if (!map)
+                                       map_tmp = realloc(map, idx + 1);
+                                       if (!map_tmp) {
+                                               free(map);
                                                ksft_exit_fail_msg("map 
realloc\n");
+                                       }
+                                       map = map_tmp;
                                        memset(map + map_len, 0, idx + 1 - 
map_len);
                                        map_len = idx + 1;
                                }
-- 
2.25.1