Re: [PATCH net 2/3] net: tls: Cancel RX async resync request on rdc_delta overflow

[Sabrina Dubroca <sd@queasysnail.net>]

2025-09-22, 10:18:52 +0300, Shahar Shitrit wrote:
> 
> 
> On 14/09/2025 21:53, Jakub Kicinski wrote:
> > On Wed, 10 Sep 2025 09:47:40 +0300 Tariq Toukan wrote:
> >> When a netdev issues an RX async resync request, the TLS module
> >> increments rcd_delta for each new record that arrives. This tracks
> >> how far the current record is from the point where synchronization
> >> was lost.
> >>
> >> When rcd_delta reaches its threshold, it indicates that the device
> >> response is either excessively delayed or unlikely to arrive at all
> >> (at that point, tcp_sn may have wrapped around, so a match would no
> >> longer be valid anyway).
> >>
> >> Previous patch introduced tls_offload_rx_resync_async_request_cancel()
> >> to explicitly cancel resync requests when a device response failure
> >> is detected.
> >>
> >> This patch adds a final safeguard: cancel the async resync request when
> >> rcd_delta crosses its threshold, as reaching this point implies that
> >> earlier cancellation did not occur.
> > 
> > Missing a Fixes tag
> Will add
> > 
> >> diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
> >> index f672a62a9a52..56c14f1647a4 100644
> >> --- a/net/tls/tls_device.c
> >> +++ b/net/tls/tls_device.c
> >> @@ -721,8 +721,11 @@ tls_device_rx_resync_async(struct tls_offload_resync_async *resync_async,
> >>  		/* shouldn't get to wraparound:
> >>  		 * too long in async stage, something bad happened
> >>  		 */
> >> -		if (WARN_ON_ONCE(resync_async->rcd_delta == USHRT_MAX))
> >> +		if (WARN_ON_ONCE(resync_async->rcd_delta == USHRT_MAX)) {
> >> +			/* cancel resync request */
> >> +			atomic64_set(&resync_async->req, 0);
> > 
> > we should probably use the helper added by the previous patch (I'd
> > probably squash them TBH)
>
> It's not trivial to use the helper here, since we don't have the socket.

tls_device_rx_resync_async doesn't currently get the socket, but it
has only one caller, tls_device_rx_resync_new_rec, which does. So
tls_device_rx_resync_async could easily get the socket. Or just pass
resync_async to tls_offload_rx_resync_async_request_cancel, since
that's what it really needs?

-- 
Sabrina