4.17-stable review patch. If anyone has any objections, please let me know.
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From: Daniel Borkmann daniel@iogearbox.net
[ Upstream commit 06030dbaf3b6c5801dcdb7fe4fbab3b91c8da84a ]
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 daniel@iogearbox.net Acked-by: Dave Watson davejwatson@fb.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/tls/tls_sw.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -755,7 +755,7 @@ 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; @@ -765,6 +765,7 @@ 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; @@ -857,6 +858,9 @@ 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: