4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Vlad Buslov <vladbu@xxxxxxxxxx>
[ 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>
---
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 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);
--
2.42.0
