5.4-stable review patch. If anyone has any objections, please let me know.
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From: Vlad Buslov vladbu@nvidia.com
[ 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@nvidia.com Signed-off-by: Vlad Buslov vladbu@nvidia.com Reviewed-by: Jiri Pirko jiri@nvidia.com Link: https://lore.kernel.org/r/20231114175915.1649154-1-vladbu@nvidia.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/macvlan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c index 545d181453504..46398b06676c0 100644 --- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -765,7 +765,7 @@ 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);