Re: [PATCH] net: xfrm: use preempt-safe this_cpu_read() in ipcomp_alloc_tfms()

From: Herbert Xu
Date: Thu Mar 08 2018 - 02:33:50 EST


On Wed, Mar 07, 2018 at 11:24:16AM -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:

How about reverting f7c83bcbfaf5 instead?

Thanks,
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
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