> On 9 Sep 2021, at 15:30, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > On Thu, Sep 09, 2021 at 01:10:05PM +0000, Haakon Bugge wrote: >> Hi Greg & Sasha, >> >> >> tl;dr: Please add 2dce224f469f ("netns: protect netns ID lookups with >> RCU") to the stable releases from v5.4 and older. It fixes a >> spin_unlock_bh() in peernet2id() called with IRQs off. I think this >> neat side-effect of commit 2dce224f469f was quite un-intentional, >> hence no Fixes: tag or CC: stable. > > Please provide a working backport for all of the relevant kernel > verisons, as it does not apply cleanly on it's own. I've done the backports. 4.9 is actually not needed, because it uses spin_{lock,unlock}_irqsave() in peernet2id(). Hence, we have an "offending" commit which this one fixes: fba143c66abb ("netns: avoid disabling irq for netns id") Will get'm out during the weekend. Thxs, Håkon