From: Jakub Kicinski Date: Fri, 24 May 2019 17:34:30 +0000 (-0700) Subject: net/tls: fix lowat calculation if some data came from previous record X-Git-Tag: v5.2-rc3~26^2~25^2~3 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=46a1695960d0600d58da7af33c65f24f3d839674;p=linux.git net/tls: fix lowat calculation if some data came from previous record If some of the data came from the previous record, i.e. from the rx_list it had already been decrypted, so it's not counted towards the "decrypted" variable, but the "copied" variable. Take that into account when checking lowat. When calculating lowat target we need to pass the original len. E.g. if lowat is at 80, len is 100 and we had 30 bytes on rx_list target would currently be incorrectly calculated as 70, even though we only need 50 more bytes to make up the 80. Fixes: 692d7b5d1f91 ("tls: Fix recvmsg() to be able to peek across multiple records") Signed-off-by: Jakub Kicinski Reviewed-by: Dirk van der Merwe Tested-by: David Beckett Signed-off-by: David S. Miller --- diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index d93f83f77864..fc13234db74a 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -1712,13 +1712,12 @@ int tls_sw_recvmsg(struct sock *sk, copied = err; } - len = len - copied; - if (len) { - target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); - timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); - } else { + if (len <= copied) goto recv_end; - } + + target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); + len = len - copied; + timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); do { bool retain_skb = false; @@ -1853,7 +1852,7 @@ int tls_sw_recvmsg(struct sock *sk, } /* If we have a new message from strparser, continue now. */ - if (decrypted >= target && !ctx->recv_pkt) + if (decrypted + copied >= target && !ctx->recv_pkt) break; } while (len);