xfrm_xlate32() translates 64-bit message provided by kernel to be sent
for 32-bit listener (acknowledge or monitor). Translator code doesn't
expect XFRMA_UNSPEC attribute as it doesn't know its payload.
Kernel never attaches such attribute, but a user can.
I've searched if any opensource does it and the answer is no.
Nothing on github and google finds only tfcproject that has such code
commented-out.
What will happen if a user sends a netlink message with XFRMA_UNSPEC
attribute? Ipsec code ignores this attribute. But if there is a
monitor-process or 32-bit user requested ack - kernel will try to
translate such message and will hit WARN_ONCE() in xfrm_xlate64_attr().
Deal with XFRMA_UNSPEC by copying the attribute payload with
xfrm_nla_cpy(). In result, the default switch-case in xfrm_xlate64_attr()
becomes an unused code. Leave those 3 lines in case a new xfrm attribute
will be added.
Fixes: 5461fc0c8d ("xfrm/compat: Add 64=>32-bit messages translator")
Reported-by: syzbot+a7e701c8385bd8543074@syzkaller.appspotmail.com
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Provide compat_xfrm_userpolicy_info translation for xfrm setsocketopt().
Reallocate buffer and put the missing padding for 64-bit message.
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Provide the user-to-kernel translator under XFRM_USER_COMPAT, that
creates for 32-bit xfrm-user message a 64-bit translation.
The translation is afterwards reused by xfrm_user code just as if
userspace had sent 64-bit message.
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Provide the kernel-to-user translator under XFRM_USER_COMPAT, that
creates for 64-bit xfrm-user message a 32-bit translation and puts it
in skb's frag_list. net/compat.c layer provides MSG_CMSG_COMPAT to
decide if the message should be taken from skb or frag_list.
(used by wext-core which has also an ABI difference)
Kernel sends 64-bit xfrm messages to the userspace for:
- multicast (monitor events)
- netlink dumps
Wire up the translator to xfrm_nlmsg_multicast().
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Add a skeleton for xfrm_compat module and provide API to register it in
xfrm_state.ko. struct xfrm_translator will have function pointers to
translate messages received from 32-bit userspace or to be sent to it
from 64-bit kernel.
module_get()/module_put() are used instead of rcu_read_lock() as the
module will vmalloc() memory for translation.
The new API is registered with xfrm_state module, not with xfrm_user as
the former needs translator for user_policy set by setsockopt() and
xfrm_user already uses functions from xfrm_state.
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
