From: Daniel Borkmann Date: Fri, 15 Jun 2018 01:07:46 +0000 (+0200) Subject: tls: fix waitall behavior in tls_sw_recvmsg X-Git-Tag: v5.4.17~5787^2~3^2 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=06030dbaf3b6c5801dcdb7fe4fbab3b91c8da84a;p=arm%2Flinux.git tls: fix waitall behavior in tls_sw_recvmsg Current behavior in tls_sw_recvmsg() is to wait for incoming tls messages and copy up to exactly len bytes of data that the user provided. This is problematic in the sense that i) if no packet is currently queued in strparser we keep waiting until one has been processed and pushed into tls receive layer for tls_wait_data() to wake up and push the decrypted bits to user space. Given after tls decryption, we're back at streaming data, use sock_rcvlowat() hint from tcp socket instead. Retain current behavior with MSG_WAITALL flag and otherwise use the hint target for breaking the loop and returning to application. This is done if currently no ctx->recv_pkt is ready, otherwise continue to process it from our strparser backlog. Fixes: c46234ebb4d1 ("tls: RX path for ktls") Signed-off-by: Daniel Borkmann Acked-by: Dave Watson Signed-off-by: David S. Miller --- diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 2945a3bd538c..f127fac88acf 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -754,7 +754,7 @@ int tls_sw_recvmsg(struct sock *sk, struct sk_buff *skb; ssize_t copied = 0; bool cmsg = false; - int err = 0; + int target, err = 0; long timeo; flags |= nonblock; @@ -764,6 +764,7 @@ int tls_sw_recvmsg(struct sock *sk, lock_sock(sk); + target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); do { bool zc = false; @@ -856,6 +857,9 @@ fallback_to_reg_recv: goto recv_end; } } + /* If we have a new message from strparser, continue now. */ + if (copied >= target && !ctx->recv_pkt) + break; } while (len); recv_end: