[PATCH 5.4 022/158] net/tls: fix corrupted data in recvmsg

Greg Kroah-Hartman
2020-11-23T13:24:09Z

From: Vadim Fedorenko <vfedorenko@novek.ru>

[ Upstream commit 3fe16edf6767decd640fa2654308bc64f8d656dc ]

If tcp socket has more data than Encrypted Handshake Message then
tls_sw_recvmsg will try to decrypt next record instead of returning
full control message to userspace as mentioned in comment. The next
message - usually Application Data - gets corrupted because it uses
zero copy for decryption that's why the data is not stored in skb
for next iteration. Revert check to not decrypt next record if
current is not Application Data.

Fixes: 692d7b5d1f91 ("tls: Fix recvmsg() to be able to peek across multiple records")
Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Link: https://lore.kernel.org/r/1605413760-21153-1-git-send-email-vfedorenko@novek.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/tls/tls_sw.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -1907,7 +1907,7 @@ pick_next_record:
* another message type
*/
msg->msg_flags |= MSG_EOR;
- if (ctx->control != TLS_RECORD_TYPE_DATA)
+ if (control != TLS_RECORD_TYPE_DATA)
goto recv_end;
} else {
break;