path: root/net/unix/diag.c
diff options
authorFelipe Gasper <felipe@felipegasper.com>2019-05-20 19:43:51 -0500
committerDavid S. Miller <davem@davemloft.net>2019-05-22 10:36:35 -0700
commitcae9910e73446cac68a54e3a7b02aaa12b689026 (patch)
treedc250270bd6fd4598e781559176e529d2c65b34d /net/unix/diag.c
parent54dee406374ce8adb352c48e175176247cb8db7c (diff)
net: Add UNIX_DIAG_UID to Netlink UNIX socket diagnostics.
This adds the ability for Netlink to report a socket's UID along with the other UNIX diagnostic information that is already available. This will allow diagnostic tools greater insight into which users control which socket. To test this, do the following as a non-root user: unshare -U -r bash nc -l -U user.socket.$$ & .. and verify from within that same session that Netlink UNIX socket diagnostics report the socket's UID as 0. Also verify that Netlink UNIX socket diagnostics report the socket's UID as the user's UID from an unprivileged process in a different session. Verify the same from a root process. Signed-off-by: Felipe Gasper <felipe@felipegasper.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/unix/diag.c')
1 files changed, 12 insertions, 0 deletions
diff --git a/net/unix/diag.c b/net/unix/diag.c
index c51a707260fa..9ff64f9df1f3 100644
--- a/net/unix/diag.c
+++ b/net/unix/diag.c
@@ -5,9 +5,11 @@
#include <linux/unix_diag.h>
#include <linux/skbuff.h>
#include <linux/module.h>
+#include <linux/uidgid.h>
#include <net/netlink.h>
#include <net/af_unix.h>
#include <net/tcp_states.h>
+#include <net/sock.h>
static int sk_diag_dump_name(struct sock *sk, struct sk_buff *nlskb)
@@ -111,6 +113,12 @@ static int sk_diag_show_rqlen(struct sock *sk, struct sk_buff *nlskb)
return nla_put(nlskb, UNIX_DIAG_RQLEN, sizeof(rql), &rql);
+static int sk_diag_dump_uid(struct sock *sk, struct sk_buff *nlskb)
+ uid_t uid = from_kuid_munged(sk_user_ns(nlskb->sk), sock_i_uid(sk));
+ return nla_put(nlskb, UNIX_DIAG_UID, sizeof(uid_t), &uid);
static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
u32 portid, u32 seq, u32 flags, int sk_ino)
@@ -157,6 +165,10 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_r
if (nla_put_u8(skb, UNIX_DIAG_SHUTDOWN, sk->sk_shutdown))
goto out_nlmsg_trim;
+ if ((req->udiag_show & UDIAG_SHOW_UID) &&
+ sk_diag_dump_uid(sk, skb))
+ goto out_nlmsg_trim;
nlmsg_end(skb, nlh);
return 0;