From 9672ab8dd01cd9a2f7c8365f8d497b605dc83c9b Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Mon, 29 Aug 2022 11:23:29 +0200 Subject: [PATCH] util: Drop any supplementary group before dropping privileges MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit a951e0b9efcb ("conf: Add --runas option, changing to given UID and GID if started as root") dropped the call to initgroups() that used to add supplementary groups corresponding to the user we'll eventually run as -- we don't need those. However, if the original user belongs to supplementary groups (usually not the case, if started as root), we don't drop those, now, and rpmlint says: passt.x86_64: E: missing-call-to-setgroups-before-setuid /usr/bin/passt passt.x86_64: E: missing-call-to-setgroups-before-setuid /usr/bin/passt.avx2 Add a call to setgroups() with an empty set, to drop any supplementary group we might currently have, before changing GID and UID. Reported-by: Daniel P. Berrangé Signed-off-by: Stefano Brivio Reviewed-by: David Gibson --- util.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/util.c b/util.c index 9b87b65..7e10deb 100644 --- a/util.c +++ b/util.c @@ -525,7 +525,7 @@ void check_root(struct ctx *c) #endif } - if (!setgid(c->gid) && !setuid(c->uid)) + if (!setgroups(0, NULL) && !setgid(c->gid) && !setuid(c->uid)) return; fprintf(stderr, "Can't change user/group, exiting");