[net] net/tls: Fix to avoid gettig invalid tls record

[Rohit Maheshwari <rohitm@chelsio.com>]

Current code doesn't check if tcp sequence number is starting from (/after)
1st record's start sequnce number. It only checks if seq number is before
1st record's end sequnce number. This problem will always be a possibility
in re-transmit case. If a record which belongs to a requested seq number is
already deleted, tls_get_record will start looking into list and as per the
check it will look if seq number is before the end seq of 1st record, which
will always be true and will return 1st record always, it should in fact
return NULL. 

Signed-off-by: Rohit Maheshwari <rohitm@chelsio.com>
---
 net/tls/tls_device.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index cd91ad812291..2898517298bf 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -602,7 +602,8 @@ struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context,
 		 */
 		info = list_first_entry_or_null(&context->records_list,
 						struct tls_record_info, list);
-		if (!info)
+		/* return NULL if seq number even before the 1st entry. */
+		if (!info || before(seq, info->end_seq - info->len))
 			return NULL;
 		record_sn = context->unacked_record_sn;
 	}
-- 
2.25.0.191.gde93cc1