From: Kamalesh Babulal Date: Mon, 8 Aug 2022 16:59:52 +0000 (-0600) Subject: api.c: add precision to fscanf(), in cgroup_populate_controllers() X-Git-Tag: v3.1.0~322 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=04169a9bef0ee77c18cd5a2e2d9f6e49f6057e32;p=thirdparty%2Flibcgroup.git api.c: add precision to fscanf(), in cgroup_populate_controllers() Fix calling risky function warning, reported by Coverity tool: CID 258305 (#1 of 1): Calling risky function (DC.STREAM_BUFFER)dont_call: fscanf assumes an arbitrarily long string, so callers must use correct precision specifiers or never use fscanf. As per secure coding standard, using '%s' in the fscanf() is not recommend, hence fix it by using the precision of macro MAX_CGROUP_TYPE_NAMELEN borrowed from Linux Kernel for the maximum allowed controller/subsys_name length. Signed-off-by: Kamalesh Babulal Signed-off-by: Tom Hromatka --- diff --git a/src/api.c b/src/api.c index df7957a1..80387946 100644 --- a/src/api.c +++ b/src/api.c @@ -1362,7 +1362,11 @@ static int cgroup_populate_controllers(char *controllers[CG_CONTROLLER_MAX]) i = 0; while (!feof(proc_cgroup)) { - err = fscanf(proc_cgroup, "%s %d %d %d", subsys_name, &hierarchy, &num_cgroups, + /* + * check Linux Kernel sources/kernel/cgroup/cgroup.c cgroup_init_early(), + * MAX_CGROUP_TYPE_NAMELEN check for details on why 32 is used. + */ + err = fscanf(proc_cgroup, "%32s %d %d %d", subsys_name, &hierarchy, &num_cgroups, &enabled); if (err < 0) break;