On Thu, 24 Sep 2020 13:20:25 +0530 Rohit Maheshwari wrote:
> At first when sendpage gets called, if there is more data, 'more' in
> tls_push_data() gets set which later sets pending_open_record_frags, but
> when there is no more data in file left, and last time tls_push_data()
> gets called, pending_open_record_frags doesn't get reset. And later when
> 2 bytes of encrypted alert comes as sendmsg, it first checks for
> pending_open_record_frags, and since this is set, it creates a record with
> 0 data bytes to encrypt, meaning record length is prepend_size + tag_size
> only, which causes problem.
Agreed, looks like the value in pending_open_record_frags may be stale.
> We should set/reset pending_open_record_frags based on more bit.
I think you implementation happens to work because there is always left
over data when more is set, but I don't think that has to be the case.
Also shouldn't we update this field or destroy the record before the
break on line 478?
> Fixes: d829e9c4112b ("tls: convert to generic sk_msg interface")
> Signed-off-by: Rohit Maheshwari <[email protected]>
> ---
> net/tls/tls_device.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
> index b74e2741f74f..a02aadefd86e 100644
> --- a/net/tls/tls_device.c
> +++ b/net/tls/tls_device.c
> @@ -492,11 +492,11 @@ static int tls_push_data(struct sock *sk,
> if (!size) {
> last_record:
> tls_push_record_flags = flags;
> - if (more) {
> - tls_ctx->pending_open_record_frags =
> - !!record->num_frags;
> + /* set/clear pending_open_record_frags based on more */
> + tls_ctx->pending_open_record_frags = !!more;
> +
> + if (more)
> break;
> - }
>
> done = true;
> }
