xsk: lock the control mutex in sock_diag interface

When accessing the members of an XDP socket, the control mutex should
be held. This commit fixes that.

Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Fixes: a36b38aa2af6 ("xsk: add sock_diag interface for AF_XDP")
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/xdp/xsk_diag.c b/net/xdp/xsk_diag.c
index 9986a759fe06..f59791ba43a0 100644
--- a/net/xdp/xsk_diag.c
+++ b/net/xdp/xsk_diag.c
@@ -97,6 +97,7 @@ static int xsk_diag_fill(struct sock *sk, struct sk_buff *nlskb,
         msg->xdiag_ino = sk_ino;
         sock_diag_save_cookie(sk, msg->xdiag_cookie);
 
+        mutex_lock(&xs->mutex);
         if ((req->xdiag_show & XDP_SHOW_INFO) && xsk_diag_put_info(xs, nlskb))
                 goto out_nlmsg_trim;
 
@@ -117,10 +118,12 @@ static int xsk_diag_fill(struct sock *sk, struct sk_buff *nlskb,
             sock_diag_put_meminfo(sk, nlskb, XDP_DIAG_MEMINFO))
                 goto out_nlmsg_trim;
 
+        mutex_unlock(&xs->mutex);
         nlmsg_end(nlskb, nlh);
         return 0;
 
 out_nlmsg_trim:
+        mutex_unlock(&xs->mutex);
         nlmsg_cancel(nlskb, nlh);
         return -EMSGSIZE;
 }