From: Mina Almasry <almasrymina@xxxxxxxxxx>
commit f3600c867c99a2cc8038680ecf211089c50e7971 upstream.
Currently on stable trees we have support for netmem/devmem RX but not
TX. It is not safe to forward/redirect an RX unreadable netmem packet
into the device's TX path, as the device may call dma-mapping APIs on
dma addrs that should not be passed to it.
Fix this by preventing the xmit of unreadable skbs.
Tested by configuring tc redirect:
sudo tc qdisc add dev eth1 ingress
sudo tc filter add dev eth1 ingress protocol ip prio 1 flower ip_proto \
tcp src_ip 192.168.1.12 action mirred egress redirect dev eth1
Before, I see unreadable skbs in the driver's TX path passed to dma
mapping APIs.
After, I don't see unreadable skbs in the driver's TX path passed to dma
mapping APIs.
Fixes: 65249feb6b3d ("net: add support for skbs with unreadable frags")
Suggested-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Mina Almasry <almasrymina@xxxxxxxxxx>
Link: https://patch.msgid.link/20250306215520.1415465-1-almasrymina@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/core/dev.c | 3 +++
1 file changed, 3 insertions(+)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3723,6 +3723,9 @@ static struct sk_buff *validate_xmit_skb
{
netdev_features_t features;
+ if (!skb_frags_readable(skb))
+ goto out_kfree_skb;
+
features = netif_skb_features(skb);
skb = validate_xmit_vlan(skb, features);
if (unlikely(!skb))
Patches currently in stable-queue which might be from almasrymina@xxxxxxxxxx are
queue-6.12/netmem-prevent-tx-of-unreadable-skbs.patch
queue-6.12/eth-bnxt-return-fail-if-interface-is-down-in-bnxt_qu.patch
