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>

1 files changed, 8 insertions, 3 deletions

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 50009c787bcd..9d3044ff45b9 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -205,17 +205,22 @@ static int ping_init_sock(struct sock *sk)
         gid_t range[2];
         struct group_info *group_info = get_current_groups();
         int i, j, count = group_info->ngroups;
+        kgid_t low, high;
 
         inet_get_ping_group_range_net(net, range, range+1);
+        low = make_kgid(&init_user_ns, range[0]);
+        high = make_kgid(&init_user_ns, range[1]);
+        if (!gid_valid(low) || !gid_valid(high) || gid_lt(high, low))
+                return -EACCES;
+
         if (range[0] <= group && group <= range[1])
                 return 0;
 
         for (i = 0; i < group_info->nblocks; i++) {
                 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
-
                 for (j = 0; j < cp_count; j++) {
-                        group = group_info->blocks[i][j];
-                        if (range[0] <= group && group <= range[1])
+                        kgid_t gid = group_info->blocks[i][j];
+                        if (gid_lte(low, gid) && gid_lte(gid, high))
                                 return 0;
                 }