Re: [PATCH net v2] atm: Fix the cleanup on alloc_mpc failure in atm_mpoa_mpoad_attach

[Paolo Abeni]

On 9/30/25 3:33 PM, Deepak Sharma wrote:
> On Tue, Sep 30, 2025 at 2:15 PM Paolo Abeni <pabeni@xxxxxxxxxx> wrote:
>> AFAICS the mpc_timer can rearm itself, so this the above is not enough
>> and you should use timer_shutdown_sync() instead.
> 
> Hi,
> 
> As I understand it, `timer_shutdown_sync` will prevent any further
> re-arming of the timer. I think this is not what we want here; since even if
> we somehow fail to allocate our first MPOA client object on our first
> ioctl call,
> and hence end up wanting to disarm the timer, maybe on next call we can
> allocate it successfully, and we would want that caches are processed
> (which are processed for every time out). So we still want it to be
> possible that
> we can re-arm it.

Ah, I missed the goal here is just being able to rearm the timer (i.e.
there is no related UaF).

Given the above, I think you could instead simply replace add_timer()
with mod_timer().

/P