[SRU][N/J][PATCH 0/2] UBUNTU: SAUCE: fan: fixes

[Alexander Mikhalitsyn]

BugLink: https://bugs.launchpad.net/bugs/2064176

SRU Justification:

[Impact]

User can trigger a host crash on Jammy/Noble by launching
a container which uses Ubuntu FAN network in LXD.

[Fix]

A first proposed patch fixes RCU locking by releasing rcu_read_lock
on the skb discard codepath.

Second patch just use a proper way (dev_core_stats_tx_dropped_inc() function)
to increase netdev's tx_dropped statistic value.

[Test Plan]

As provided by Max Asnaashari:

# Install LXD from channel latest/stable
snap install lxd --channel latest/stable

# Configure LXD
lxd init --auto

# Create a FAN network
lxc network create lxdfan0 bridge.mode=fan ipv4.nat=true

# Launch a container using the FAN network
lxc launch ubuntu-minimal:22.04 c1 --network lxdfan0

# Try to interact with LXD
lxc ls

[Where problems could occur]

Change is local and only related to Ubuntu FAN code. I would not expect
any problems with this patchset.

Link: https://github.com/canonical/lxd/issues/14025
Reported-by: Max Asnaashari <max.asnaashari at canonical.com>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn at canonical.com>

Alexander Mikhalitsyn (2):
  UBUNTU: SAUCE: fan: release rcu_read_lock on skb discard path
  UBUNTU: SAUCE: fan: fix racy device stat update

 drivers/net/vxlan/vxlan_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

-- 
2.34.1