Commit 5170d0fe authored by Eric Dumazet's avatar Eric Dumazet Committed by Ziyang Xuan
Browse files

xfrm/compat: prevent potential spectre v1 gadget in xfrm_xlate32_attr() 

stable inclusion
from stable-v5.10.168
commit a893cc644812728e86e9aff517fd5698812ecef0
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9R4LF
CVE: CVE-2023-52746

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a893cc644812728e86e9aff517fd5698812ecef0



--------------------------------

[ Upstream commit b6ee8963 ]

  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: 5106f4a8 ("xfrm/compat: Add 32=>64-bit messages translator")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Dmitry Safonov <dima@arista.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Reviewed-by: default avatarDmitry Safonov <dima@arista.com>
Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarZiyang Xuan <william.xuanziyang@huawei.com>
parent ff7390bf

net/xfrm/xfrm_compat.c

+2 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
 * Based on code and translator idea by: Florian Westphal <fw@strlen.de>

 */

#include <linux/compat.h>

#include <linux/nospec.h>

#include <linux/xfrm.h>

#include <net/xfrm.h>
@@ -435,6 +436,7 @@ static int xfrm_xlate32_attr(void *dst, const struct nlattr *nla, 
		NL_SET_ERR_MSG(extack, "Bad attribute");

		return -EOPNOTSUPP;

	}

	type = array_index_nospec(type, XFRMA_MAX + 1);

	if (nla_len(nla) < compat_policy[type].len) {

		NL_SET_ERR_MSG(extack, "Attribute bad length");

		return -EOPNOTSUPP;