Re: Re: [PATCH] sfc: fix a double-free bug in efx_probe_filters

From: alexious
Date: Wed Dec 20 2023 - 12:31:42 EST



> On Thu, Dec 14, 2023 at 11:22:46PM +0800, Zhipeng Lu wrote:
> > In efx_probe_filters, the channel->rps_flow_id is freed in a
> > efx_for_each_channel marco when success equals to 0.
> > However, after the following call chain:
> >
> > efx_probe_filters
> > |-> ef100_net_open
> > |-> ef100_net_stop
> > |-> efx_remove_filters
>
> I think the call chain may be a bit more like:
>
> ef100_net_open
> |-> efx_probe_filters
> |-> ef100_net_stop
> |-> efx_remove_filters
>
> >
> > The channel->rps_flow_id is freed again in the efx_for_each_channel of
> > efx_remove_filters, triggering a double-free bug.
> >
> > Fixes: a9dc3d5612ce ("sfc_ef100: RX filter table management and related gubbins")
> > Signed-off-by: Zhipeng Lu <alexious@xxxxxxxxxx>
>
> The above nit not withstanding, I agree with your reasoning.
> And that the problem was introduced in the cited commit.
>
> Reviewed-by: Simon Horman <horms@xxxxxxxxxx>

Sorry for the call-chain's problem, I was not familiar with it at that time.
Thanks for Simon's correction. Appreciate!
I'll soon send a v2 patch with the corrected call-chain and RB tags.