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

[Daniel Borkmann]

On 6/14/20 9:04 PM, Gaurav Singh wrote:

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 <gaurav1...@gmail.com>

Squashed all three same fixes into one and pushed to bpf, thanks!

@@ -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));

For the record, this one is buggy, so I fixed it up as well.

        if (!rec) {
                fprintf(stderr, "Mem alloc error\n");
                exit(EXIT_FAIL_MEM);

Thanks,
Daniel