Re: [PATCH v2 net 2/2] net/sched: taprio: make qdisc_leaf() see the per-netdev-queue pfifo child qdiscs

[Greg Kroah-Hartman]

On Wed, Feb 22, 2023 at 04:25:07PM +0200, Vladimir Oltean wrote:
> +Greg, Sasha.

Hint, in the future, please cc: stable@xxxxxxxxxxxxxxx with stable
kernel requests, I know I don't see stuff that isn't cc:ed there
normally when working on that tree.

> 
> Hi Kurt,
> 
> On Wed, Feb 22, 2023 at 03:03:04PM +0100, Kurt Kanzenbach wrote:
> > This commit was backported to v5.15-LTS which results in NULL pointer
> > dereferences e.g., when attaching an ETF child qdisc to taprio.
> > 
> > From what I can see is, that the issue was reported back then and this
> > commit was reverted [1]. However, the revert didn't make it into
> > v5.15-LTS? Is there a reason for it? I'm testing 5.15.94-rt59 here.
> > 
> > Thanks,
> > Kurt
> > 
> > [1] - https://lore.kernel.org/all/20221004220100.1650558-1-vladimir.oltean@xxxxxxx/
> 
> You are right; the patchwork-bot clearly says that the revert was
> applied to net.git as commit af7b29b1deaa ("Revert "net/sched: taprio:
> make qdisc_leaf() see the per-netdev-queue pfifo child qdiscs""), but
> the revert never made it to stable.
> 
> OTOH, the original patch did make it to, and still is in, linux-stable.
> I have backport notification emails of the original to 5.4, 5.10, 5.15, 5.19.
> 
> Greg, Sasha, can you please pick up and backport commit af7b29b1deaa
> ("Revert "net/sched: taprio: make qdisc_leaf() see the per-netdev-queue
> pfifo child qdiscs"") to the currently maintained stable kernels?

Now queued up, thanks.

greg k-h