Re: [PATCH net-next 2/2] xfrm: Fix unaligned access in xfrm_notify_sa() for DELSA
From: Steffen Klassert <steffen.klassert@secunet.com>
Date: 2015-10-21 06:57:10
Also in:
linux-crypto, lkml
On Mon, Oct 19, 2015 at 05:23:29PM -0400, Sowmini Varadhan wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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