Commit 2d151d39073a ("xfrm: Add possibility to set the default to block
if we have no policy") broke ABI by changing the value of the XFRM_MSG_MAPPING
enum item, thus also evading the build-time check
in security/selinux/nlmsgtab.c:selinux_nlmsg_lookup for presence of proper
security permission checks in nlmsg_xfrm_perms. Fix it by placing
XFRM_MSG_SETDEFAULT/XFRM_MSG_GETDEFAULT to the end of the enum, right before
__XFRM_MSG_MAX, and updating the nlmsg_xfrm_perms accordingly.
Fixes: 2d151d39073a ("xfrm: Add possibility to set the default to block if we have no policy")
References: https://lore.kernel.org/netdev/20210901151402.GA2557@xxxxxxxxxxxx/
Signed-off-by: Eugene Syromiatnikov <esyr@xxxxxxxxxx>
---
v2:
- Updated SELinux nlmsg_xfrm_perms permissions table and selinux_nlmsg_lookup
build-time check accordingly.
v1: https://lore.kernel.org/lkml/20210901153407.GA20446@xxxxxxxxxxxxxxxxx/
---
include/uapi/linux/xfrm.h | 6 +++---
security/selinux/nlmsgtab.c | 4 +++-
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/include/uapi/linux/xfrm.h b/include/uapi/linux/xfrm.h
index b96c1ea..26f456b1 100644
--- a/include/uapi/linux/xfrm.h
+++ b/include/uapi/linux/xfrm.h
@@ -213,13 +213,13 @@ enum {
XFRM_MSG_GETSPDINFO,
#define XFRM_MSG_GETSPDINFO XFRM_MSG_GETSPDINFO
+ XFRM_MSG_MAPPING,
+#define XFRM_MSG_MAPPING XFRM_MSG_MAPPING
+
XFRM_MSG_SETDEFAULT,
#define XFRM_MSG_SETDEFAULT XFRM_MSG_SETDEFAULT
XFRM_MSG_GETDEFAULT,
#define XFRM_MSG_GETDEFAULT XFRM_MSG_GETDEFAULT
-
- XFRM_MSG_MAPPING,
-#define XFRM_MSG_MAPPING XFRM_MSG_MAPPING
__XFRM_MSG_MAX
};
#define XFRM_MSG_MAX (__XFRM_MSG_MAX - 1)
diff --git a/security/selinux/nlmsgtab.c b/security/selinux/nlmsgtab.c
index d59276f..94ea2a8 100644
--- a/security/selinux/nlmsgtab.c
+++ b/security/selinux/nlmsgtab.c
@@ -126,6 +126,8 @@ static const struct nlmsg_perm nlmsg_xfrm_perms[] =
{ XFRM_MSG_NEWSPDINFO, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
{ XFRM_MSG_GETSPDINFO, NETLINK_XFRM_SOCKET__NLMSG_READ },
{ XFRM_MSG_MAPPING, NETLINK_XFRM_SOCKET__NLMSG_READ },
+ { XFRM_MSG_SETDEFAULT, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
+ { XFRM_MSG_GETDEFAULT, NETLINK_XFRM_SOCKET__NLMSG_READ },
};
static const struct nlmsg_perm nlmsg_audit_perms[] =
@@ -189,7 +191,7 @@ int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm)
* structures at the top of this file with the new mappings
* before updating the BUILD_BUG_ON() macro!
*/
- BUILD_BUG_ON(XFRM_MSG_MAX != XFRM_MSG_MAPPING);
+ BUILD_BUG_ON(XFRM_MSG_MAX != XFRM_MSG_GETDEFAULT);
err = nlmsg_perm(nlmsg_type, perm, nlmsg_xfrm_perms,
sizeof(nlmsg_xfrm_perms));
break;
--
2.1.4
