malloc: fix potential null pointer dereference

We need to do the NULL pointer check first after malloc().

Fixes: 07dcbfe0101f ("malloc: support multiprocess memory hotplug")
Cc: stable@dpdk.org
Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>

diff --git a/lib/librte_eal/common/malloc_heap.c b/lib/librte_eal/common/malloc_heap.c
index 12aaf2d..ac7bbb3 100644 (file)
--- a/lib/librte_eal/common/malloc_heap.c
+++ b/lib/librte_eal/common/malloc_heap.c
@@ -326,11 +326,9 @@ try_expand_heap_primary(struct malloc_heap *heap, uint64_t pg_sz,
 
        /* we can't know in advance how many pages we'll need, so we malloc */
        ms = malloc(sizeof(*ms) * n_segs);
-
-       memset(ms, 0, sizeof(*ms) * n_segs);
-
        if (ms == NULL)
                return -1;
+       memset(ms, 0, sizeof(*ms) * n_segs);
 
        elem = alloc_pages_on_heap(heap, pg_sz, elt_size, socket, flags, align,
                        bound, contig, ms, n_segs);

diff --git a/lib/librte_eal/common/malloc_mp.c b/lib/librte_eal/common/malloc_mp.c
index 931c14b..5f2d4e0 100644 (file)
--- a/lib/librte_eal/common/malloc_mp.c
+++ b/lib/librte_eal/common/malloc_mp.c
@@ -194,13 +194,11 @@ handle_alloc_request(const struct malloc_mp_req *m,
 
        /* we can't know in advance how many pages we'll need, so we malloc */
        ms = malloc(sizeof(*ms) * n_segs);
-
-       memset(ms, 0, sizeof(*ms) * n_segs);
-
        if (ms == NULL) {
                RTE_LOG(ERR, EAL, "Couldn't allocate memory for request state\n");
                goto fail;
        }
+       memset(ms, 0, sizeof(*ms) * n_segs);
 
        elem = alloc_pages_on_heap(heap, ar->page_sz, ar->elt_size, ar->socket,
                        ar->flags, ar->align, ar->bound, ar->contig, ms,