net: fix skb leak in __skb_tstamp_tx()

commit 8a02fb71d7192ff1a9a47c9d937624966c6e09af upstream.

Commit 50749f2dd685 ("tcp/udp: Fix memleaks of sk and zerocopy skbs with
TX timestamp.") added a call to skb_orphan_frags_rx() to fix leaks with
zerocopy skbs. But it ended up adding a leak of its own. When
skb_orphan_frags_rx() fails, the function just returns, leaking the skb
it just cloned. Free it before returning.

This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc.

Fixes: 50749f2dd685 ("tcp/udp: Fix memleaks of sk and zerocopy skbs with TX timestamp.")
Signed-off-by: Pratyush Yadav <ptyadav@amazon.de>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20230522153020.32422-1-ptyadav@amazon.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index fb6b3f2ae1921b2ffb160236ef6fbbfc510d2a4d..e203172b9b9e7831a623e32917af93d14c6eaf00 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4751,8 +4751,10 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb,
        } else {
                skb = skb_clone(orig_skb, GFP_ATOMIC);
 
-               if (skb_orphan_frags_rx(skb, GFP_ATOMIC))
+               if (skb_orphan_frags_rx(skb, GFP_ATOMIC)) {
+                       kfree_skb(skb);
                        return;
+               }
        }
        if (!skb)
                return;