| Description: | The Linux kernel through 3.17.4 does not properly restrict dropping of supplemental group memberships in certain namespace scenarios, which allows local users to bypass intended file permissions by leveraging a POSIX ACL containing an entry for the group category that is more restrictive than the entry for the other category, aka a "negative groups" issue, related to kernel/groups.c, kernel/uid16.c, and kernel/user_namespace.c. A flaw was discovered in how supplemental group memberships are handled in certain namespace scenarios. A local user could exploit this flaw to bypass file permission restrictions.
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