* [PATCH] [bpf] xdp_redirect_cpu_user: Fix null pointer dereference
@ 2020-06-14 19:04 Gaurav Singh
2020-06-16 7:07 ` John Fastabend
2020-06-16 13:10 ` Daniel Borkmann
0 siblings, 2 replies; 3+ messages in thread
From: Gaurav Singh @ 2020-06-14 19:04 UTC (permalink / raw)
To: gaurav1086, Alexei Starovoitov, Daniel Borkmann, Martin KaFai Lau,
Song Liu, Yonghong Song, Andrii Nakryiko, John Fastabend,
KP Singh, David S. Miller, Jakub Kicinski, Jesper Dangaard Brouer,
open list:BPF (Safe dynamic programs and tools),
open list:BPF (Safe dynamic programs and tools), open list
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
^ permalink raw reply related [flat|nested] 3+ messages in thread* RE: [PATCH] [bpf] xdp_redirect_cpu_user: Fix null pointer dereference
2020-06-14 19:04 [PATCH] [bpf] xdp_redirect_cpu_user: Fix null pointer dereference Gaurav Singh
@ 2020-06-16 7:07 ` John Fastabend
2020-06-16 13:10 ` Daniel Borkmann
1 sibling, 0 replies; 3+ messages in thread
From: John Fastabend @ 2020-06-16 7:07 UTC (permalink / raw)
To: Gaurav Singh, gaurav1086, Alexei Starovoitov, Daniel Borkmann,
Martin KaFai Lau, Song Liu, Yonghong Song, Andrii Nakryiko,
John Fastabend, KP Singh, David S. Miller, Jakub Kicinski,
Jesper Dangaard Brouer,
(open list:BPF \(Safe dynamic programs and tools\)),
open list:BPF (Safe dynamic programs and tools),
(open list:BPF \(Safe dynamic programs and tools\) open list)
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 <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
>
Acked-by: John Fastabend <john.fastabend@gmail.com>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] [bpf] xdp_redirect_cpu_user: Fix null pointer dereference
2020-06-14 19:04 [PATCH] [bpf] xdp_redirect_cpu_user: Fix null pointer dereference Gaurav Singh
2020-06-16 7:07 ` John Fastabend
@ 2020-06-16 13:10 ` Daniel Borkmann
1 sibling, 0 replies; 3+ messages in thread
From: Daniel Borkmann @ 2020-06-16 13:10 UTC (permalink / raw)
To: Gaurav Singh, Alexei Starovoitov, Martin KaFai Lau, Song Liu,
Yonghong Song, Andrii Nakryiko, John Fastabend, KP Singh,
David S. Miller, Jakub Kicinski, Jesper Dangaard Brouer,
open list:BPF (Safe dynamic programs and tools),
open list:BPF (Safe dynamic programs and tools), open list
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 <gaurav1086@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
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2020-06-16 13:10 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2020-06-14 19:04 [PATCH] [bpf] xdp_redirect_cpu_user: Fix null pointer dereference Gaurav Singh
2020-06-16 7:07 ` John Fastabend
2020-06-16 13:10 ` Daniel Borkmann
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox