This is a note to let you know that I've just added the patch titled net/af_packet: check len when min_header_len equals to 0 to the 5.10-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-af_packet-check-len-when-min_header_len-equals-to-0.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From dc633700f00f726e027846a318c5ffeb8deaaeda Mon Sep 17 00:00:00 2001 From: Zhengchao Shao <shaozhengchao@xxxxxxxxxx> Date: Wed, 27 Jul 2022 17:33:12 +0800 Subject: net/af_packet: check len when min_header_len equals to 0 From: Zhengchao Shao <shaozhengchao@xxxxxxxxxx> commit dc633700f00f726e027846a318c5ffeb8deaaeda upstream. User can use AF_PACKET socket to send packets with the length of 0. When min_header_len equals to 0, packet_snd will call __dev_queue_xmit to send packets, and sock->type can be any type. Reported-by: syzbot+5ea725c25d06fb9114c4@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: fd1894224407 ("bpf: Don't redirect packets with invalid pkt_len") Signed-off-by: Zhengchao Shao <shaozhengchao@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/packet/af_packet.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2986,8 +2986,8 @@ static int packet_snd(struct socket *soc if (err) goto out_free; - if (sock->type == SOCK_RAW && - !dev_validate_header(dev, skb->data, len)) { + if ((sock->type == SOCK_RAW && + !dev_validate_header(dev, skb->data, len)) || !skb->len) { err = -EINVAL; goto out_free; } Patches currently in stable-queue which might be from shaozhengchao@xxxxxxxxxx are queue-5.10/bpf-don-t-redirect-packets-with-invalid-pkt_len.patch queue-5.10/net-af_packet-check-len-when-min_header_len-equals-to-0.patch