[PATCHv2 33/59] keys/mktme: Require CAP_SYS_RESOURCE capability for MKTME keys

Kirill A. Shutemov
2019-07-31T15:23:58Z

From: Alison Schofield <alison.schofield@intel.com>

The MKTME key type uses capabilities to restrict the allocation
of keys to privileged users. CAP_SYS_RESOURCE is required, but
the broader capability of CAP_SYS_ADMIN is accepted.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
security/keys/mktme_keys.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/security/keys/mktme_keys.c b/security/keys/mktme_keys.c
index 1e2afcce7d85..2d90cc83e5ce 100644
--- a/security/keys/mktme_keys.c
+++ b/security/keys/mktme_keys.c
@@ -2,6 +2,7 @@

/* Documentation/x86/mktme/ */

+#include <linux/cred.h>
#include <linux/cpu.h>
#include <linux/init.h>
#include <linux/key.h>
@@ -371,6 +372,9 @@ int mktme_preparse_payload(struct key_preparsed_payload *prep)
char *options;
int ret;

+ if (!capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
if (datalen <= 0 || datalen > 1024 || !prep->data)
return -EINVAL;

--
2.21.0