According to all consumers code of attrs[XFRMA_SEC_CTX], like
* verify_sec_ctx_len(), convert to xfrm_user_sec_ctx*
* xfrm_state_construct(), call security_xfrm_state_alloc whose prototype
is int security_xfrm_state_alloc(.., struct xfrm_user_sec_ctx *sec_ctx);
* copy_from_user_sec_ctx(), convert to xfrm_user_sec_ctx *
...
It seems that the expected parsing result for XFRMA_SEC_CTX should be
structure xfrm_user_sec_ctx, and the current xfrm_sec_ctx is confusing
and misleading (Luckily, they happen to have same size 8 bytes).
This commit amend the policy structure to xfrm_user_sec_ctx to avoid
ambiguity.
Fixes: cf5cb79f69 ("[XFRM] netlink: Establish an attribute policy")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
int type = nla_type(nla);
if (type > XFRMA_MAX) {
return -EOPNOTSUPP;
}
@type is then used as an array index and can be used
as a Spectre v1 gadget.
if (nla_len(nla) < compat_policy[type].len) {
array_index_nospec() can be used to prevent leaking
content of kernel memory to malicious users.
Fixes: 5106f4a8ac ("xfrm/compat: Add 32=>64-bit messages translator")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Dmitry Safonov <dima@arista.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Reviewed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Kernel generates mapping change message, XFRM_MSG_MAPPING,
when a source port chage is detected on a input state with UDP
encapsulation set. Kernel generates a message for each IPsec packet
with new source port. For a high speed flow per packet mapping change
message can be excessive, and can overload the user space listener.
Introduce rate limiting for XFRM_MSG_MAPPING message to the user space.
The rate limiting is configurable via netlink, when adding a new SA or
updating it. Use the new attribute XFRMA_MTIMER_THRESH in seconds.
v1->v2 change:
update xfrm_sa_len()
v2->v3 changes:
use u32 insted unsigned long to reduce size of struct xfrm_state
fix xfrm_ompat size Reported-by: kernel test robot <lkp@intel.com>
accept XFRM_MSG_MAPPING only when XFRMA_ENCAP is present
Co-developed-by: Thomas Egerer <thomas.egerer@secunet.com>
Signed-off-by: Thomas Egerer <thomas.egerer@secunet.com>
Signed-off-by: Antony Antony <antony.antony@secunet.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
The attribute-translator has to take in mind maxtype, that is
xfrm_link::nla_max. When it is set, attributes are not of xfrm_attr_type_t.
Currently, they can be only XFRMA_SPD_MAX (message XFRM_MSG_NEWSPDINFO),
their UABI is the same for 64/32-bit, so just copy them.
Thanks to YueHaibing for reporting this:
In xfrm_user_rcv_msg_compat() if maxtype is not zero and less than
XFRMA_MAX, nlmsg_parse_deprecated() do not initialize attrs array fully.
xfrm_xlate32() will access uninit 'attrs[i]' while iterating all attrs
array.
KASAN: probably user-memory-access in range [0x0000000041b58ab0-0x0000000041b58ab7]
CPU: 0 PID: 15799 Comm: syz-executor.2 Tainted: G W 5.14.0-rc1-syzkaller #0
RIP: 0010:nla_type include/net/netlink.h:1130 [inline]
RIP: 0010:xfrm_xlate32_attr net/xfrm/xfrm_compat.c:410 [inline]
RIP: 0010:xfrm_xlate32 net/xfrm/xfrm_compat.c:532 [inline]
RIP: 0010:xfrm_user_rcv_msg_compat+0x5e5/0x1070 net/xfrm/xfrm_compat.c:577
[...]
Call Trace:
xfrm_user_rcv_msg+0x556/0x8b0 net/xfrm/xfrm_user.c:2774
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
xfrm_netlink_rcv+0x6b/0x90 net/xfrm/xfrm_user.c:2824
netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929
sock_sendmsg_nosec net/socket.c:702 [inline]
Fixes: 5106f4a8ac ("xfrm/compat: Add 32=>64-bit messages translator")
Cc: <stable@kernel.org>
Reported-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Replace WARN_ONCE() that can be triggered from userspace with
pr_warn_once(). Those still give user a hint what's the issue.
I've left WARN()s that are not possible to trigger with current
code-base and that would mean that the code has issues:
- relying on current compat_msg_min[type] <= xfrm_msg_min[type]
- expected 4-byte padding size difference between
compat_msg_min[type] and xfrm_msg_min[type]
- compat_policy[type].len <= xfrma_policy[type].len
(for every type)
Reported-by: syzbot+834ffd1afc7212eb8147@syzkaller.appspotmail.com
Fixes: 5f3eea6b7e ("xfrm/compat: Attach xfrm dumps to 64=>32 bit translator")
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: netdev@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
32-bit to 64-bit messages translator zerofies needed paddings in the
translation, the rest is the actual payload.
Don't allocate zero pages as they are not needed.
Fixes: 5106f4a8ac ("xfrm/compat: Add 32=>64-bit messages translator")
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
32-bit messages translated by xfrm_compat can have attributes attached.
For all, but XFRMA_SA, XFRMA_POLICY the size of payload is the same
in 32-bit UABI and 64-bit UABI. For XFRMA_SA (struct xfrm_usersa_info)
and XFRMA_POLICY (struct xfrm_userpolicy_info) it's only tail-padding
that is present in 64-bit payload, but not in 32-bit.
The proper size for destination nlattr is already calculated by
xfrm_user_rcv_calculate_len64() and allocated with kvmalloc().
xfrm_attr_cpy32() copies 32-bit copy_len into 64-bit attribute
translated payload, zero-filling possible padding for SA/POLICY.
Due to a typo, *pos already has 64-bit payload size, in a result next
memset(0) is called on the memory after the translated attribute, not on
the tail-padding of it.
Fixes: 5106f4a8ac ("xfrm/compat: Add 32=>64-bit messages translator")
Reported-by: syzbot+c43831072e7df506a646@syzkaller.appspotmail.com
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
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>
