bpf, xdp, samples: Fix null pointer dereference in *_user code
Memset on the pointer right after malloc can cause a NULL pointer
deference if it failed to allocate memory. A simple fix is to
replace malloc()/memset() pair with a simple call to calloc().
Fixes: 0fca931a6f21 ("samples/bpf: program demonstrating access to xdp_rxq_info")
Signed-off-by: Gaurav Singh <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Jesper Dangaard Brouer <[email protected]>
Acked-by: John Fastabend <[email protected]>
diff --git a/samples/bpf/xdp_monitor_user.c b/samples/bpf/xdp_monitor_user.c
index dd558cb..ef53b93 100644
--- a/samples/bpf/xdp_monitor_user.c
+++ b/samples/bpf/xdp_monitor_user.c
@@ -509,11 +509,8 @@ static void *alloc_rec_per_cpu(int record_size)
{
unsigned int nr_cpus = bpf_num_possible_cpus();
void *array;
- size_t size;
- size = record_size * nr_cpus;
- array = malloc(size);
- memset(array, 0, size);
+ array = calloc(nr_cpus, record_size);
if (!array) {
fprintf(stderr, "Mem alloc error (nr_cpus:%u)\n", nr_cpus);
exit(EXIT_FAIL_MEM);
@@ -528,8 +525,7 @@ static struct stats_record *alloc_stats_record(void)
int i;
/* Alloc main stats_record structure */
- rec = malloc(sizeof(*rec));
- memset(rec, 0, sizeof(*rec));
+ rec = calloc(1, sizeof(*rec));
if (!rec) {
fprintf(stderr, "Mem alloc error\n");
exit(EXIT_FAIL_MEM);
