Re: [PATCH net] net/sched: mqprio: fix stack out-of-bounds write in tc entry parsing

[Cong Wang]

On Wed, Jul 23, 2025 at 01:55:21PM +0100, Simon Horman wrote:
> + Ferenc and Vladimir
> 
> On Tue, Jul 22, 2025 at 04:51:21PM +0100, Maher Azzouzi wrote:
> > From: MaherAzzouzi <maherazz04@xxxxxxxxx>
> 
> nit: space between your names please
> 
> > 
> > TCA_MQPRIO_TC_ENTRY_INDEX is validated using
> > NLA_POLICY_MAX(NLA_U32, TC_QOPT_MAX_QUEUE), which allows the value
> > TC_QOPT_MAX_QUEUE (16). This leads to a 4-byte out-of-bounds stack write in
> > the fp[] array, which only has room for 16 elements (0–15).
> > 
> > Fix this by changing the policy to allow only up to TC_QOPT_MAX_QUEUE - 1.
> > 
> > Fixes: f62af20bed2d ("net/sched: mqprio: allow per-TC user input of FP adminStatus")
> > Reported-by: Maher Azzouzi <maherazz04@xxxxxxxxx>
> 
> I don't think there is any need to include a Reported-by tag if
> you are also the patch author.

+1

> 
> > Signed-off-by: Maher Azzouzi <maherazz04@xxxxxxxxx>
> 
> I agree with your analysis and that this is a good fix.
> 
> Reviewed-by: Simon Horman <horms@xxxxxxxxxx>

Reviewed-by: Cong Wang <xiyou.wangcong@xxxxxxxxx>


Thanks for the patch.