Add NULL checks after malloc() in three helper functions to prevent NULL pointer dereference on memory allocation failure. - cg_name() - cg_name_indexed() - cg_control()
These functions allocate memory with malloc() but previously called snprintf() unconditionally, which would trigger undefined behavior if allocation fails. Signed-off-by: Hongfu Li <[email protected]> --- tools/testing/selftests/cgroup/lib/cgroup_util.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/cgroup/lib/cgroup_util.c b/tools/testing/selftests/cgroup/lib/cgroup_util.c index 6a7295347e90..0c5e6d4bbc3a 100644 --- a/tools/testing/selftests/cgroup/lib/cgroup_util.c +++ b/tools/testing/selftests/cgroup/lib/cgroup_util.c @@ -59,7 +59,8 @@ char *cg_name(const char *root, const char *name) size_t len = strlen(root) + strlen(name) + 2; char *ret = malloc(len); - snprintf(ret, len, "%s/%s", root, name); + if (ret) + snprintf(ret, len, "%s/%s", root, name); return ret; } @@ -69,7 +70,8 @@ char *cg_name_indexed(const char *root, const char *name, int index) size_t len = strlen(root) + strlen(name) + 10; char *ret = malloc(len); - snprintf(ret, len, "%s/%s_%d", root, name, index); + if (ret) + snprintf(ret, len, "%s/%s_%d", root, name, index); return ret; } @@ -79,7 +81,8 @@ char *cg_control(const char *cgroup, const char *control) size_t len = strlen(cgroup) + strlen(control) + 2; char *ret = malloc(len); - snprintf(ret, len, "%s/%s", cgroup, control); + if (ret) + snprintf(ret, len, "%s/%s", cgroup, control); return ret; } -- 2.25.1
