PM: hibernate: Fix potential memory leak in hibernate_preallocate_mem…

…ory() and prepare_highmem_image()

hibernate_preallocate_memory() and prepare_highmem_image() allocates
memory chunk with memory_bm_create(). When the function gets some error
after memory_bm_create(), relavent memory should be released with
memory_bm_free().

Fix it by calling memory_bm_free() at the right time.

Signed-off-by: Jianglei Nie <niejianglei2021@163.com>

kernel/power/snapshot.c

@@ -1752,6 +1752,7 @@ int hibernate_preallocate_memory(void)
 
 	error = memory_bm_create(&copy_bm, GFP_IMAGE, PG_ANY);
 	if (error) {
+		memory_bm_free(orig_bm, PG_UNSAFE_CLEAR);
 		pr_err("Cannot allocate copy bitmap\n");
 		goto err_out;
 	}
@@ -2335,8 +2336,10 @@ static int prepare_highmem_image(struct memory_bitmap *bm,
 	if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
 		return -ENOMEM;
 
-	if (get_highmem_buffer(PG_SAFE))
+	if (get_highmem_buffer(PG_SAFE)) {
+		memory_bm_free(bm, PG_UNSAFE_CLEAR);
 		return -ENOMEM;
+	}
 
 	to_alloc = count_free_highmem_pages();
 	if (to_alloc > *nr_highmem_p)