--- mcelog.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/mcelog.c +++ b/mcelog.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include #include "mcelog.h" @@ -1284,6 +1285,14 @@ static void drop_cred(void) { + /* When dropping privileges from root, the `setgroups` call will + * remove any extraneous groups. If we don't call this, then + * even though our uid has dropped, we may still have groups + * that enable us to do super-user things. This will fail if we + * aren't root, so don't bother checking the return value, this + * is just done as an optimistic privilege dropping function. + */ + setgroups(0, NULL); if (runcred.uid != -1U && runcred.gid == -1U) { struct passwd *pw = getpwuid(runcred.uid); if (pw)