This is a note to let you know that I've just added the patch titled net: hsr: Fix potential use-after-free to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-hsr-fix-potential-use-after-free.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 840c568a123a2f2614ad6721da5a0cddc6a8c323 Author: YueHaibing <yuehaibing@xxxxxxxxxx> Date: Fri Nov 25 15:57:24 2022 +0800 net: hsr: Fix potential use-after-free [ Upstream commit 7e177d32442b7ed08a9fa61b61724abc548cb248 ] The skb is delivered to netif_rx() which may free it, after calling this, dereferencing skb may trigger use-after-free. Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)") Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx> Link: https://lore.kernel.org/r/20221125075724.27912-1-yuehaibing@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/hsr/hsr_forward.c b/net/hsr/hsr_forward.c index 04b5450c5a55..adfb49760678 100644 --- a/net/hsr/hsr_forward.c +++ b/net/hsr/hsr_forward.c @@ -207,17 +207,18 @@ static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev, struct hsr_node *node_src) { bool was_multicast_frame; - int res; + int res, recv_len; was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST); hsr_addr_subst_source(node_src, skb); skb_pull(skb, ETH_HLEN); + recv_len = skb->len; res = netif_rx(skb); if (res == NET_RX_DROP) { dev->stats.rx_dropped++; } else { dev->stats.rx_packets++; - dev->stats.rx_bytes += skb->len; + dev->stats.rx_bytes += recv_len; if (was_multicast_frame) dev->stats.multicast++; }