userns: Convert group_info values from gid_t to kgid_t.
As a first step to converting struct cred to be all kuid_t and kgid_t
values convert the group values stored in group_info to always be
kgid_t values. Unless user namespaces are used this change should
have no effect.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
diff --git a/kernel/uid16.c b/kernel/uid16.c
index 51c6e89..e530bc3 100644
--- a/kernel/uid16.c
+++ b/kernel/uid16.c
@@ -134,11 +134,14 @@
static int groups16_to_user(old_gid_t __user *grouplist,
struct group_info *group_info)
{
+ struct user_namespace *user_ns = current_user_ns();
int i;
old_gid_t group;
+ kgid_t kgid;
for (i = 0; i < group_info->ngroups; i++) {
- group = high2lowgid(GROUP_AT(group_info, i));
+ kgid = GROUP_AT(group_info, i);
+ group = high2lowgid(from_kgid_munged(user_ns, kgid));
if (put_user(group, grouplist+i))
return -EFAULT;
}
@@ -149,13 +152,20 @@
static int groups16_from_user(struct group_info *group_info,
old_gid_t __user *grouplist)
{
+ struct user_namespace *user_ns = current_user_ns();
int i;
old_gid_t group;
+ kgid_t kgid;
for (i = 0; i < group_info->ngroups; i++) {
if (get_user(group, grouplist+i))
return -EFAULT;
- GROUP_AT(group_info, i) = low2highgid(group);
+
+ kgid = make_kgid(user_ns, low2highgid(group));
+ if (!gid_valid(kgid))
+ return -EINVAL;
+
+ GROUP_AT(group_info, i) = kgid;
}
return 0;