net: tls: fix marking packets as decrypted

For TLS offload we mark packets with skb->decrypted to make sure
they don't escape the host without getting encrypted first.
The crypto state lives in the socket, so it may get detached
by a call to skb_orphan(). As a safety check - the egress path
drops all packets with skb->decrypted and no "crypto-safe" socket.

The skb marking was added to sendpage only (and not sendmsg),
because tls_device injected data into the TCP stack using sendpage.
This special case was missed when sendpage got folded into sendmsg.

Fixes: c5c37af6ecad ("tcp: Convert do_tcp_sendpages() to use MSG_SPLICE_PAGES")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240530232607.82686-1-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 681b54e..4d8cc2e 100644 (file)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1165,6 +1165,9 @@ new_segment:
 
                        process_backlog++;
 
+#ifdef CONFIG_SKB_DECRYPTED
+                       skb->decrypted = !!(flags & MSG_SENDPAGE_DECRYPTED);
+#endif
                        tcp_skb_entail(sk, skb);
                        copy = size_goal;