ACK: [SRU][B/F][PATCH v3 0/1] vrf: fix refcnt leak with vxlan slaves

[Kleber Souza]

On 06.10.21 18:47, Luke Nowakowski-Krijger wrote:
> This is a backport request by Nicolas Dichtel <nicolas.dichtel at 6wind.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1945180
> 
> [Impact]
> 
> There are cases, where deleting a VRF device can hang waiting for the refcnt
> to drop to 0, with the message:
>    unregister_netdevice: waiting for vrf1 to become free. Usage count = 1
> 
> This is fixed upstream with commit b87b04f5019e
> ("ipv4: Fix device used for dst_alloc with local routes"), included in linux
> v5.13. The original patch, which has introduced the bug, is included in
> linux v4.10.
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b87b04f5019e
> 
> [Backports for Bionic]
> 
> Removed updates to tools/testing/selftests/net/fib_tests.sh as they do not
> exist for bionic. Also changed the struct referenced in the patch from
> fib_nh_common to fib_nh as well as the associated accesses to the
> struct.
> 
> [Test Case]
> 
> Reproduced the bug with the upstream test case which also is the test in
> the original patch added to fib_tests.sh.
> Confirmed that after the patch was applied the test case does not hang
> and successfully removes VRF device.
> 
> [Regression Potential]
> 
> Relatively straightforward in that it links a new dst to a vrf device
> isntead of the loopback if there is a valid nexthop device.
> 
> David Ahern (1):
>    ipv4: Fix device used for dst_alloc with local routes
> 
>   net/ipv4/route.c                         | 16 ++++++++++++++-
>   tools/testing/selftests/net/fib_tests.sh | 25 ++++++++++++++++++++++++
>   2 files changed, 40 insertions(+), 1 deletion(-)
> 

Acked-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>

Thanks