net/cdc_ncm: Fix multicast RX support for CDC NCM devices with ZLP

Origin: https://git.kernel.org/linus/748064b54c99418f615aabff5755996cd9816969
Bug-Debian: https://bugs.debian.org/1024328

ZLP for DisplayLink ethernet devices was enabled in 6.0:
266c0190aee3 ("net/cdc_ncm: Enable ZLP for DisplayLink ethernet devices").
The related driver_info should be the "same as cdc_ncm_info, but with
FLAG_SEND_ZLP". However, set_rx_mode that enables handling multicast
traffic was missing in the new cdc_ncm_zlp_info.

usbnet_cdc_update_filter rx mode was introduced in linux 5.9 with:
e10dcb1b6ba7 ("net: cdc_ncm: hook into set_rx_mode to admit multicast
traffic")

Without this hook, multicast, and then IPv6 SLAAC, is broken.

Fixes: 266c0190aee3 ("net/cdc_ncm: Enable ZLP for DisplayLink ethernet devices")
Signed-off-by: Santiago Ruano Rincón <santiago.ruano-rincon@imt-atlantique.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Gbp-Pq: Topic bugfix/all
Gbp-Pq: Name net-cdc_ncm-Fix-multicast-RX-support-for-CDC-NCM-dev.patch

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 10dc2c1e1421c310fbc8cf5e2529a31b6775546e..953708b89b2f714d81a003d4f7f9380e085ae573 100644 (file)
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -1911,6 +1911,7 @@ static const struct driver_info cdc_ncm_zlp_info = {
        .status = cdc_ncm_status,
        .rx_fixup = cdc_ncm_rx_fixup,
        .tx_fixup = cdc_ncm_tx_fixup,
+       .set_rx_mode = usbnet_cdc_update_filter,
 };
 
 /* Same as cdc_ncm_info, but with FLAG_WWAN */