Re: [PATCH] netfilter: fix ordering of jumpstack allocation and table update

[Will Deacon <will.deacon@arm.com>]

Hi Pablo,

On Fri, Oct 18, 2013 at 12:15:36PM +0100, Pablo Neira Ayuso wrote:
> On Thu, Oct 17, 2013 at 02:24:33PM +0100, Will Deacon wrote:
> > During kernel stability testing on an SMP ARMv7 system, Yalin Wang
> > reported the following panic from the netfilter code:

[...]

> > This patch adds an smp_wmb() before the assignment to table->private
> > (which is essentially publishing newinfo) to ensure that all writes to
> > newinfo will be observed before plugging it into the table structure.
> > A dependent-read barrier is also added on the consumer side, to ensure
> > the same ordering requirement are also respected there.
> 
> We also need fixes for net/ipv6/netfilter/ip6_tables.c and
> net/ipv4/netfilter/arp_tables.c as well. Could you extend this patch
> and resend?

Sure, I can try, but that's going to require a bit of time to sit down and
look at the shared data, access order, dependencies etc. I'm currently
preparing for Edinburgh, so it might be a while before I get a chance to
extend this.

Will