Messages in this thread | | | Date | Wed, 21 Oct 2015 06:17:37 -0700 (PDT) | Subject | Re: [PATCH net-next 2/2] xfrm: Fix unaligned access in xfrm_notify_sa() for DELSA | From | David Miller <> |
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From: Sowmini Varadhan <sowmini.varadhan@oracle.com> Date: Wed, 21 Oct 2015 06:54:42 -0400
> On (10/21/15 08:57), Steffen Klassert wrote: >> > --- a/net/xfrm/xfrm_user.c >> > +++ b/net/xfrm/xfrm_user.c >> > @@ -2659,7 +2659,7 @@ static int xfrm_notify_sa(struct xfrm_state *x, const struct km_event *c) >> > if (attr == NULL) >> > goto out_free_skb; >> > >> > - p = nla_data(attr); >> > + p = PTR_ALIGN(nla_data(attr), __alignof__(*p)); >> >> Hm, this breaks userspace notifications on 64-bit systems. >> Userspace expects this to be aligned to 4, with your patch >> it is aligned to 8 on 64-bit. >> >> Without your patch I get the correct notification when deleting a SA: >> > > But __alignof__(*p) is 8 on sparc, and without the patch I get > all types of unaligned access. So what do you suggest as the fix?
The accesses have to be done using something like get_unaligned() and put_unaligned().
Sorry, but the protocol is set in stone and this is unfortunately how it is.
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