userns: Use kgids for sysctl_ping_group_range

- Store sysctl_ping_group_range as a paire of kgid_t values
  instead of a pair of gid_t values.
- Move the kgid conversion work from ping_init_sock into ipv4_ping_group_range
- For invalid cases reset to the default disabled state.

With the kgid_t conversion made part of the original value sanitation
from userspace understand how the code will react becomes clearer
and it becomes possible to set the sysctl ping group range from
something other than the initial user namespace.

Cc: Vasiliy Kulikov <segoon@openwall.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 1474dd6..3516dc0 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -5,6 +5,7 @@
 #ifndef __NETNS_IPV4_H__
 #define __NETNS_IPV4_H__
 
+#include <linux/uidgid.h>
 #include <net/inet_frag.h>
 
 struct tcpm_hash_bucket;
@@ -62,7 +63,7 @@ struct netns_ipv4 {
 	int sysctl_icmp_ratemask;
 	int sysctl_icmp_errors_use_inbound_ifaddr;
 
-	unsigned int sysctl_ping_group_range[2];
+	kgid_t sysctl_ping_group_range[2];
 	long sysctl_tcp_mem[3];
 
 	atomic_t rt_genid;