From 90aca415b2917dbb16512b5299f0d5118cf0748c Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 5 Dec 2014 19:36:04 -0600 Subject: userns: Allow setting gid_maps without privilege when setgroups is disabled commit 66d2f338ee4c449396b6f99f5e75cd18eb6df272 upstream. Now that setgroups can be disabled and not reenabled, setting gid_map without privielge can now be enabled when setgroups is disabled. This restores most of the functionality that was lost when unprivileged setting of gid_map was removed. Applications that use this functionality will need to check to see if they use setgroups or init_groups, and if they don't they can be fixed by simply disabling setgroups before writing to gid_map. Reviewed-by: Andy Lutomirski Signed-off-by: "Eric W. Biederman" Signed-off-by: Jiri Slaby --- kernel/user_namespace.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'kernel') diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 7737b3da335c..c09fe8b87cb0 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -812,6 +812,11 @@ static bool new_idmap_permitted(const struct file *file, kuid_t uid = make_kuid(ns->parent, id); if (uid_eq(uid, cred->euid)) return true; + } else if (cap_setid == CAP_SETGID) { + kgid_t gid = make_kgid(ns->parent, id); + if (!(ns->flags & USERNS_SETGROUPS_ALLOWED) && + gid_eq(gid, cred->egid)) + return true; } } -- cgit v1.2.3