On 03/07/2018 12:21 PM, Eric Dumazet wrote: > On Wed, 2018-03-07 at 11:24 -0800, Greg Hackmann wrote: >> f7c83bcbfaf5 ("net: xfrm: use __this_cpu_read per-cpu helper") added >> a >> __this_cpu_read() call inside ipcomp_alloc_tfms(). Since this call >> was >> introduced, the rules around per-cpu accessors have been tightened >> and >> __this_cpu_read() cannot be used in a preemptible context. >> >> syzkaller reported this leading to the following kernel BUG while >> fuzzing sendmsg: >> >> >> Cc: sta...@vger.kernel.org > > Hi Greg, thanks for this patch. > > 1) Please read Documentation/networking/netdev-FAQ.txt > around line 133 > > 2) If you believe this needs to be backported, you must provide > a Fixes: tag to clearly identify commit that changed the behavior. > > Otherwise dozens of stable teams will have to figure out by themselves, > wasting precious time. > > Thanks. >
Apologies, I forgot that netdev has its own stable rules. I'll double-check which kernels are impacted and resend with an updated commit log.