From: Gaurav Singh gaurav1086@gmail.com
[ Upstream commit 6903cdae9f9f08d61e49c16cbef11c293e33a615 ]
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 gaurav1086@gmail.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: Jesper Dangaard Brouer brouer@redhat.com Acked-by: John Fastabend john.fastabend@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- samples/bpf/xdp_monitor_user.c | 8 ++------ samples/bpf/xdp_redirect_cpu_user.c | 7 ++----- samples/bpf/xdp_rxq_info_user.c | 13 +++---------- 3 files changed, 7 insertions(+), 21 deletions(-)
diff --git a/samples/bpf/xdp_monitor_user.c b/samples/bpf/xdp_monitor_user.c index dd558cbb23094..ef53b93db5732 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); diff --git a/samples/bpf/xdp_redirect_cpu_user.c b/samples/bpf/xdp_redirect_cpu_user.c index 767869e3b308f..0a76725568225 100644 --- a/samples/bpf/xdp_redirect_cpu_user.c +++ b/samples/bpf/xdp_redirect_cpu_user.c @@ -210,11 +210,8 @@ 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); @@ -229,11 +226,11 @@ static struct stats_record *alloc_stats_record(void)
size = sizeof(*rec) + n_cpus * sizeof(struct record); rec = malloc(size); - memset(rec, 0, size); if (!rec) { fprintf(stderr, "Mem alloc error\n"); exit(EXIT_FAIL_MEM); } + memset(rec, 0, size); rec->rx_cnt.cpu = alloc_record_per_cpu(); rec->redir_err.cpu = alloc_record_per_cpu(); rec->kthread.cpu = alloc_record_per_cpu(); diff --git a/samples/bpf/xdp_rxq_info_user.c b/samples/bpf/xdp_rxq_info_user.c index b88df17853b84..21d6e5067a839 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);