net: Fix ns_capable check in sock_diag_put_filterinfo

The caller needs capabilities on the namespace being queried, not on
their own namespace.  This is a security bug, although it likely has
only a minor impact.

Cc: stable@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/sock_diag.h b/include/linux/sock_diag.h
index 54f91d3..302ab80 100644 (file)
--- a/include/linux/sock_diag.h
+++ b/include/linux/sock_diag.h
@@ -23,7 +23,7 @@ int sock_diag_check_cookie(void *sk, __u32 *cookie);
 void sock_diag_save_cookie(void *sk, __u32 *cookie);
 
 int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attr);
-int sock_diag_put_filterinfo(struct user_namespace *user_ns, struct sock *sk,
+int sock_diag_put_filterinfo(struct sock *sk,
                             struct sk_buff *skb, int attrtype);
 
 #endif

diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c
index d7af188..9deb6ab 100644 (file)
--- a/net/core/sock_diag.c
+++ b/net/core/sock_diag.c
@@ -49,7 +49,7 @@ int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype)
 }
 EXPORT_SYMBOL_GPL(sock_diag_put_meminfo);
 
-int sock_diag_put_filterinfo(struct user_namespace *user_ns, struct sock *sk,
+int sock_diag_put_filterinfo(struct sock *sk,
                             struct sk_buff *skb, int attrtype)
 {
        struct sock_fprog_kern *fprog;
@@ -58,7 +58,7 @@ int sock_diag_put_filterinfo(struct user_namespace *user_ns, struct sock *sk,
        unsigned int flen;
        int err = 0;
 
-       if (!ns_capable(user_ns, CAP_NET_ADMIN)) {
+       if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
                nla_reserve(skb, attrtype, 0);
                return 0;
        }

diff --git a/net/packet/diag.c b/net/packet/diag.c
index 533ce4f..435ff99 100644 (file)
--- a/net/packet/diag.c
+++ b/net/packet/diag.c
@@ -172,7 +172,7 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
                goto out_nlmsg_trim;
 
        if ((req->pdiag_show & PACKET_SHOW_FILTER) &&
-           sock_diag_put_filterinfo(user_ns, sk, skb, PACKET_DIAG_FILTER))
+           sock_diag_put_filterinfo(sk, skb, PACKET_DIAG_FILTER))
                goto out_nlmsg_trim;
 
        return nlmsg_end(skb, nlh);