| Message ID | 20200612185328.4671-1-gaurav1086@gmail.com |
|---|---|
| State | Accepted |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | xdp_rxq_info_user: Fix null pointer dereference. Replace malloc/memset with calloc. | expand |
On Fri, 12 Jun 2020 14:53:27 -0400 Gaurav Singh <gaurav1086@gmail.com> wrote: > 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 with a calloc() > > Fixes: 0fca931a6f21 ("samples/bpf: program demonstrating access to xdp_rxq_info") > Signed-off-by: Gaurav Singh <gaurav1086@gmail.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Jesper Dangaard Brouer wrote: > On Fri, 12 Jun 2020 14:53:27 -0400 > Gaurav Singh <gaurav1086@gmail.com> wrote: > > > 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 with a calloc() > > > > Fixes: 0fca931a6f21 ("samples/bpf: program demonstrating access to xdp_rxq_info") > > Signed-off-by: Gaurav Singh <gaurav1086@gmail.com> > > Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> > Acked-by: John Fastabend <john.fastabend@gmail.com>
diff --git a/samples/bpf/xdp_rxq_info_user.c b/samples/bpf/xdp_rxq_info_user.c index 4fe47502ebed..caa4e7ffcfc7 100644 --- a/samples/bpf/xdp_rxq_info_user.c +++ b/samples/bpf/xdp_rxq_info_user.c @@ -198,11 +198,8 @@ 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); @@ -214,11 +211,8 @@ static struct record *alloc_record_per_rxq(void) { unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries; struct record *array; - size_t size; - size = sizeof(struct record) * nr_rxqs; - array = malloc(size); - memset(array, 0, size); + array = calloc(nr_rxqs, sizeof(struct record)); if (!array) { fprintf(stderr, "Mem alloc error (nr_rxqs:%u)\n", nr_rxqs); exit(EXIT_FAIL_MEM); @@ -232,8 +226,7 @@ static struct stats_record *alloc_stats_record(void) struct stats_record *rec; int i; - rec = malloc(sizeof(*rec)); - memset(rec, 0, sizeof(*rec)); + rec = calloc(1, sizeof(struct stats_record)); if (!rec) { fprintf(stderr, "Mem alloc error\n"); exit(EXIT_FAIL_MEM);
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 with a calloc() Fixes: 0fca931a6f21 ("samples/bpf: program demonstrating access to xdp_rxq_info") Signed-off-by: Gaurav Singh <gaurav1086@gmail.com> --- samples/bpf/xdp_rxq_info_user.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-)