bpf_map_value_size() uses num_possible_cpus() to determine map size, but
some of the tests only allocate enough memory for online cpus. This
results in out-of-bound writes in userspace during bpf(BPF_MAP_LOOKUP_ELEM)
syscalls in cases when number of online cpus is lower than the number of
possible cpus. Fix by switching from get_nprocs_conf() to
bpf_num_possible_cpus() when determining the number of processors in
these tests (test_progs/netcnt and test_cgroup_storage).
Signed-off-by: Artem Savkov <asavkov@xxxxxxxxxx>
---
tools/testing/selftests/bpf/prog_tests/netcnt.c | 2 +-
tools/testing/selftests/bpf/test_cgroup_storage.c | 3 ++-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/netcnt.c b/tools/testing/selftests/bpf/prog_tests/netcnt.c
index 954964f0ac3d..d3915c58d0e1 100644
--- a/tools/testing/selftests/bpf/prog_tests/netcnt.c
+++ b/tools/testing/selftests/bpf/prog_tests/netcnt.c
@@ -25,7 +25,7 @@ void serial_test_netcnt(void)
if (!ASSERT_OK_PTR(skel, "netcnt_prog__open_and_load"))
return;
- nproc = get_nprocs_conf();
+ nproc = bpf_num_possible_cpus();
percpu_netcnt = malloc(sizeof(*percpu_netcnt) * nproc);
if (!ASSERT_OK_PTR(percpu_netcnt, "malloc(percpu_netcnt)"))
goto err;
diff --git a/tools/testing/selftests/bpf/test_cgroup_storage.c b/tools/testing/selftests/bpf/test_cgroup_storage.c
index d6a1be4d8020..2ffa08198d1c 100644
--- a/tools/testing/selftests/bpf/test_cgroup_storage.c
+++ b/tools/testing/selftests/bpf/test_cgroup_storage.c
@@ -7,6 +7,7 @@
#include <sys/sysinfo.h>
#include "bpf_rlimit.h"
+#include "bpf_util.h"
#include "cgroup_helpers.h"
#include "testing_helpers.h"
@@ -44,7 +45,7 @@ int main(int argc, char **argv)
unsigned long long *percpu_value;
int cpu, nproc;
- nproc = get_nprocs_conf();
+ nproc = bpf_num_possible_cpus();
percpu_value = malloc(sizeof(*percpu_value) * nproc);
if (!percpu_value) {
printf("Not enough memory for per-cpu area (%d cpus)\n", nproc);
--
2.34.1
