| Message ID | 65f37efeff5af105c89493dda4f38c61e4cd495f.1445286755.git.sowmini.varadhan@oracle.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Herbert Xu |
| Headers | show |
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.varadhan@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. Without your patch I get the correct notification when deleting a SA: ip x m Deleted src 172.16.0.2 dst 172.16.0.1 proto esp spi 0x00000002 reqid 2 mode tunnel replay-window 32 auth-trunc hmac(sha1) 0x31323334353637383930 96 enc cbc(aes) 0x31323334353637383930313233343536 sel src 10.0.0.0/24 dst 192.168.0.0/24 With your patch I get for the same SA: ip x m Deleted src 50.0.0.0 dst 0.0.0.0 proto 0 reqid 0 mode transport replay-window 0 flag decap-dscp auth-trunc hmac(sha1) 0x31323334353637383930 96 enc cbc(aes) 0x31323334353637383930313233343536 sel src 0.0.0.0/0 dst 0.234.255.255/0 proto igmp -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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? (and openswan/pluto dont flag any errors with the patch, which is a separate bug). --Sowmini -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Steffen Klassert <steffen.klassert@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.varadhan@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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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. -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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)); } err = copy_to_user_state_extra(x, p, skb); if (err)
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.varadhan@oracle.com> --- net/xfrm/xfrm_user.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)