This is a note to let you know that I've just added the patch titled net: handle ARPHRD_PPP in dev_is_mac_header_xmit() 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-handle-arphrd_ppp-in-dev_is_mac_header_xmit.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. >From a4f39c9f14a634e4cd35fcd338c239d11fcc73fc Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx> Date: Wed, 23 Aug 2023 15:41:02 +0200 Subject: net: handle ARPHRD_PPP in dev_is_mac_header_xmit() From: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx> commit a4f39c9f14a634e4cd35fcd338c239d11fcc73fc upstream. The goal is to support a bpf_redirect() from an ethernet device (ingress) to a ppp device (egress). The l2 header is added automatically by the ppp driver, thus the ethernet header should be removed. CC: stable@xxxxxxxxxxxxxxx Fixes: 27b29f63058d ("bpf: add bpf_redirect() helper") Signed-off-by: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx> Tested-by: Siwar Zitouni <siwar.zitouni@xxxxxxxxx> Reviewed-by: Guillaume Nault <gnault@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/linux/if_arp.h | 4 ++++ 1 file changed, 4 insertions(+) --- a/include/linux/if_arp.h +++ b/include/linux/if_arp.h @@ -56,6 +56,10 @@ static inline bool dev_is_mac_header_xmi case ARPHRD_NONE: case ARPHRD_RAWIP: case ARPHRD_PIMREG: + /* PPP adds its l2 header automatically in ppp_start_xmit(). + * This makes it look like an l3 device to __bpf_redirect() and tcf_mirred_init(). + */ + case ARPHRD_PPP: return false; default: return true; Patches currently in stable-queue which might be from nicolas.dichtel@xxxxxxxxx are queue-4.14/net-handle-arphrd_ppp-in-dev_is_mac_header_xmit.patch