ACK/Cmnt: [SRU][Impish][PATCH 0/1] CVE-2022-28356

[Tim Gardner]

Acked-by: Tim Gardner <tim.gardner at canonical.com>

I feel like the upstream stable patch should have come from 5.15.y, but 
since the 5.10.y patch is virtually identical, I'm not caring that much.

On 6/12/22 17:49, Cengiz Can wrote:
> [Impact]
> In the Linux kernel before 5.17.1, a refcount leak bug was found in
> net/llc/af_llc.c.
> 
> [Fix]
> Upstream fix for this uses a function introduced with 5.17-rc1
> `dev_put_track`.
> (commit 4d92b95ff2f9 "net: add net device refcount tracker
> infrastructure").
> 
> There's a stable backport of this fix that doesn't require net device
> refcount tracker functionality.
> 
> So, this was cherry-picked from the fix on linux-5.10-y.
> 
> [Test case]
> Author publicly shared a PoC which renders the targeted network
> interface non-removable. This prevents the instance from rebooting
> properly. (Not the actual exploit but an enabler to it).
> 
> Verified that impish and xenial are both vulnerable to this, compiled
> and booted both of them with this patch and made sure that PoC is no
> longer causing any lockups.
> 
> [Potential regression]
> Logical Link Control interface is pretty critical. But the changes are
> miniscule and probably won't cause any regressions.
> 
> Eric Dumazet (1):
>    llc: fix netdevice reference leaks in llc_ui_bind()
> 
>   net/llc/af_llc.c | 8 ++++++++
>   1 file changed, 8 insertions(+)
> 

-- 
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Tim Gardner
Canonical, Inc