[dm-devel] [dm- devel][PATCH] vector: return null when realloc fails in vector_alloc_slot func

[Zhiqiang Liu]

In vector_alloc_slot func, if REALLOC fails, it means new slot
allocation fails. However, it just update v->allocated and then
return the old v->slot without new slot. So, the caller will take
the last old slot as the new allocated slot, and use it by calling
vector_set_slot func. Finally, the data of last slot is lost.

Here, if REALLOC or MALLOC fails, we will return NULL.

Signed-off-by: Zhiqiang Liu <liuzhiqiang26 at huawei.com>
Signed-off-by: lixiaokeng <lixiaokeng at huawei.com>
---
 libmultipath/vector.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/libmultipath/vector.c b/libmultipath/vector.c
index 501cf4c5..29dc9848 100644
--- a/libmultipath/vector.c
+++ b/libmultipath/vector.c
@@ -49,12 +49,14 @@ vector_alloc_slot(vector v)
 	else
 		new_slot = (void *) MALLOC(sizeof (void *) * v->allocated);

-	if (!new_slot)
+	/* If REALLOC or MALLOC fails, it means new slot allocation fails, so return NULL. */
+	if (!new_slot) {
 		v->allocated -= VECTOR_DEFAULT_SIZE;
-	else
-		v->slot = new_slot;
+		return NULL;
+	}

-	return v->slot;
+	v->slot = new_slot;
+	return v->slot[VECTOR_SIZE(v) - 1];
 }

 int
-- 
2.24.0.windows.2