From: Eric Dumazet <eric.dumazet@gmail.com>
To: Greg Hackmann <ghackmann@google.com>,
Steffen Klassert <steffen.klassert@secunet.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
"David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: xfrm: use preempt-safe this_cpu_read() in ipcomp_alloc_tfms()
Date: Wed, 07 Mar 2018 12:21:21 -0800 [thread overview]
Message-ID: <1520454081.109662.54.camel@gmail.com> (raw)
In-Reply-To: <20180307192416.233202-1-ghackmann@google.com>
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: stable@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.
next prev parent reply other threads:[~2018-03-07 20:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-07 19:24 [PATCH] net: xfrm: use preempt-safe this_cpu_read() in ipcomp_alloc_tfms() Greg Hackmann
2018-03-07 20:21 ` Eric Dumazet [this message]
2018-03-07 20:50 ` Greg Hackmann
2018-03-08 7:33 ` Herbert Xu
2018-03-08 16:31 ` Eric Dumazet
2018-03-08 18:40 ` Herbert Xu
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