From: Kamalesh Babulal Date: Wed, 10 Aug 2022 16:52:09 +0000 (-0600) Subject: api.c: add precision to fscanf(), in cgroup_get_current_controller_path() X-Git-Tag: v3.1.0~321 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ac05eb49c498aa5047070a4620456fa7a10e1910;p=thirdparty%2Flibcgroup.git api.c: add precision to fscanf(), in cgroup_get_current_controller_path() Fix calling risky function warning, reported by Coverity tool: CID 258301 (#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 FILENAME_MAX borrowed from Linux Kernel for the maximum allowed controller/subsys_name length. Signed-off-by: Kamalesh Babulal Signed-off-by: Tom Hromatka TJH: Small fix in the commit comment. --- diff --git a/src/api.c b/src/api.c index 80387946..5c6de111 100644 --- a/src/api.c +++ b/src/api.c @@ -4526,7 +4526,11 @@ int cgroup_get_current_controller_path(pid_t pid, const char *controller, char * char *token; int num; - ret = fscanf(pid_cgroup_fd, "%d:%[^:]:%s\n", &num, controllers, cgroup_path); + /* + * 4096 == FILENAME_MAX, keeping the coverity happy with precision + * for the cgroup_path. + */ + ret = fscanf(pid_cgroup_fd, "%d:%[^:]:%4096s\n", &num, controllers, cgroup_path); /* * Magic numbers like "3" seem to be integrating into my daily * life, I need some magic to help make them disappear :)