From: Steffen Klassert <steffen.klass...@secunet.com> Date: Wed, 21 Oct 2015 08:57:04 +0200
> On Mon, Oct 19, 2015 at 05:23:29PM -0400, Sowmini Varadhan wrote: >> On sparc, deleting established SAs (e.g., by restarting ipsec >> at the peer) results in unaligned access messages via >> xfrm_del_sa -> km_state_notify -> xfrm_send_state_notify(). >> Use an aligned pointer to xfrm_usersa_info for this case. >> >> Signed-off-by: Sowmini Varadhan <sowmini.varad...@oracle.com> >> --- >> net/xfrm/xfrm_user.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c >> index a8de9e3..158ef4a 100644 >> --- 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. That's correct, netlink attributes are fundamentally only 4 byte aligned and this cannot be changed. nla_data() is exactly where the attribute must be placed, aligned or not. The only workaround is, when designing netlink attributes. Various netlink libraries have workarounds for accessing, for example, 64-bit stats which are going to be unaligned in netlink messages. -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
