Bug#535571: kernel unaligned access copy_to_user_state with IPSec

[Jonathan Nieder <jrnieder@gmail.com>]

found 535571 linux-2.6/2.6.32-30
quit

Hi,

ja nein wrote:

> [1046073.600266] Kernel unaligned access at TPC[104ea7fc] copy_to_user_state+0x54/0x9c [xfrm_user]
> [1046073.715755] Kernel unaligned access at TPC[104ea7fc] copy_to_user_state+0x54/0x9c [xfrm_user]
>
> It happens as soon as there's traffic over the tunnel.

I suspect this is still the case in 3.x, too.

Can you use addr2line to find which variable is being accessed to trip
this message?

The problem is (at least I think) just as you mentioned: netlink
attributes are only 4-byte aligned but "struct xfrm_usersa_info" is
8-byte aligned because it contains a struct xfrm_lifetime_cfg.  Though
I don't see why memcpy() would have misbehaved before
v2.6.33-rc3~1^2~10 (sparc: Stop trying to be so fancy and use
__builtin_{memcpy,memset}(), 2009-12-10).