[PATCH] [bpf] xdp_redirect_cpu_user: Fix null pointer dereference

[Gaurav Singh <gaurav1086@gmail.com>]

Memset() on the pointer right after malloc() can cause
a null pointer dereference if it failed to allocate memory.
Fix this by replacing malloc/memset with a single calloc().

Signed-off-by: Gaurav Singh <gaurav1086@gmail.com>
---
 samples/bpf/xdp_redirect_cpu_user.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/samples/bpf/xdp_redirect_cpu_user.c b/samples/bpf/xdp_redirect_cpu_user.c
index f3468168982e..2ae7a9a1d950 100644
--- a/samples/bpf/xdp_redirect_cpu_user.c
+++ b/samples/bpf/xdp_redirect_cpu_user.c
@@ -207,11 +207,8 @@ static struct datarec *alloc_record_per_cpu(void)
 {
 	unsigned int nr_cpus = bpf_num_possible_cpus();
 	struct datarec *array;
-	size_t size;
 
-	size = sizeof(struct datarec) * nr_cpus;
-	array = malloc(size);
-	memset(array, 0, size);
+	array = calloc(nr_cpus, sizeof(struct datarec));
 	if (!array) {
 		fprintf(stderr, "Mem alloc error (nr_cpus:%u)\n", nr_cpus);
 		exit(EXIT_FAIL_MEM);
@@ -222,11 +219,9 @@ static struct datarec *alloc_record_per_cpu(void)
 static struct stats_record *alloc_stats_record(void)
 {
 	struct stats_record *rec;
-	int i, size;
+	int i;
 
-	size = sizeof(*rec) + n_cpus * sizeof(struct record);
-	rec = malloc(size);
-	memset(rec, 0, size);
+	rec = calloc(n_cpus + 1, sizeof(struct record));
 	if (!rec) {
 		fprintf(stderr, "Mem alloc error\n");
 		exit(EXIT_FAIL_MEM);
-- 
2.17.1