Re: [PATCH net v3] bridge: cfm: reject invalid CCM interval at configuration time

On Tue, Jun 9, 2026 at 12:19 AM Nikolay Aleksandrov <[email protected]> wrote:
>
> On 09/06/2026 09:51, Xiang Mei wrote:
> > Thanks for your review and the tip. V4 was sent.
> >
> > Xiang
> >
>
> Please don't top post on netdev@.
>
Thanks for the tip!

Xiang
> Cheers,
>   Nik
>
> > On Mon, Jun 8, 2026 at 11:46 PM Ido Schimmel <[email protected]> wrote:
> >>
> >> On Sat, Jun 06, 2026 at 02:58:48PM -0700, Xiang Mei wrote:
> >>> ccm_tx_work_expired() re-arms itself via queue_delayed_work() using
> >>> the configured exp_interval converted by interval_to_us(). When
> >>> exp_interval is BR_CFM_CCM_INTERVAL_NONE or out of range,
> >>> interval_to_us() returns 0, causing the worker to fire immediately in
> >>> a tight loop that allocates skbs until OOM.
> >>>
> >>> Fix this by validating exp_interval at configuration time:
> >>>
> >>>   - Constrain IFLA_BRIDGE_CFM_CC_CONFIG_EXP_INTERVAL to the valid range
> >>>     [BR_CFM_CCM_INTERVAL_3_3_MS, BR_CFM_CCM_INTERVAL_10_MIN] in the
> >>>     netlink policy so userspace cannot set an invalid value.
> >>>
> >>>   - Reject starting CCM TX in br_cfm_cc_ccm_tx() when exp_interval has
> >>>     not yet been configured (defaults to 0 from kzalloc).
> >>>
> >>> Fixes: 2be665c3940d ("bridge: cfm: Netlink SET configuration Interface.")
> >>> Reported-by: Weiming Shi <[email protected]>
> >>> Suggested-by: Ido Schimmel <[email protected]>
> >>> Signed-off-by: Xiang Mei <[email protected]>
> >>
> >> Reviewed-by: Ido Schimmel <[email protected]>
> >>
> >> Nit: I don't think that the Suggested-by is appropriate here since I
> >> merely had minor comments on the previous version.
>