This is a note to let you know that I've just added the patch titled macvlan: Don't propagate promisc change to lower dev in passthru to the 4.19-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: macvlan-don-t-propagate-promisc-change-to-lower-dev-.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit ee9e36ce2a761a782146dfb05b9c24b7c27bf602 Author: Vlad Buslov <vladbu@xxxxxxxxxx> Date: Tue Nov 14 18:59:15 2023 +0100 macvlan: Don't propagate promisc change to lower dev in passthru [ Upstream commit 7e1caeace0418381f36b3aa8403dfd82fc57fc53 ] Macvlan device in passthru mode sets its lower device promiscuous mode according to its MACVLAN_FLAG_NOPROMISC flag instead of synchronizing it to its own promiscuity setting. However, macvlan_change_rx_flags() function doesn't check the mode before propagating such changes to the lower device which can cause net_device->promiscuity counter overflow as illustrated by reproduction example [0] and resulting dmesg log [1]. Fix the issue by first verifying the mode in macvlan_change_rx_flags() function before propagating promiscuous mode change to the lower device. [0]: ip link add macvlan1 link enp8s0f0 type macvlan mode passthru ip link set macvlan1 promisc on ip l set dev macvlan1 up ip link set macvlan1 promisc off ip l set dev macvlan1 down ip l set dev macvlan1 up [1]: [ 5156.281724] macvlan1: entered promiscuous mode [ 5156.285467] mlx5_core 0000:08:00.0 enp8s0f0: entered promiscuous mode [ 5156.287639] macvlan1: left promiscuous mode [ 5156.288339] mlx5_core 0000:08:00.0 enp8s0f0: left promiscuous mode [ 5156.290907] mlx5_core 0000:08:00.0 enp8s0f0: entered promiscuous mode [ 5156.317197] mlx5_core 0000:08:00.0 enp8s0f0: promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken. Fixes: efdbd2b30caa ("macvlan: Propagate promiscuity setting to lower devices.") Reviewed-by: Gal Pressman <gal@xxxxxxxxxx> Signed-off-by: Vlad Buslov <vladbu@xxxxxxxxxx> Reviewed-by: Jiri Pirko <jiri@xxxxxxxxxx> Link: https://lore.kernel.org/r/20231114175915.1649154-1-vladbu@xxxxxxxxxx Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c index e1f95fd08d721..29d5fd46c09a0 100644 --- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -769,7 +769,7 @@ static void macvlan_change_rx_flags(struct net_device *dev, int change) if (dev->flags & IFF_UP) { if (change & IFF_ALLMULTI) dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1); - if (change & IFF_PROMISC) + if (!macvlan_passthru(vlan->port) && change & IFF_PROMISC) dev_set_promiscuity(lowerdev, dev->flags & IFF_PROMISC ? 1 : -1);