From: Zoran Markovic <zmarkovic@sierrawireless.com>
To: <linux-security-module@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Cc: Zoran Markovic <zmarkovic@sierrawireless.com>,
Casey Schaufler <casey@schaufler-ca.com>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>
Subject: [RFC PATCH] smack: fix access permissions for keyring
Date: Wed, 17 Oct 2018 16:25:44 -0700 [thread overview]
Message-ID: <1539818744-30912-1-git-send-email-zmarkovic@sierrawireless.com> (raw)
Function smack_key_permission() only issues smack requests for the
following operations:
- KEY_NEED_READ (issues MAY_READ)
- KEY_NEED_WRITE (issues MAY_WRITE)
- KEY_NEED_LINK (issues MAY_WRITE)
- KEY_NEED_SETATTR (issues MAY_WRITE)
A blank smack request is issued in all other cases, resulting in
smack access being granted if there is any rule defined between
subject and object, or denied with -EACCES otherwise.
Request MAY_READ access for KEY_NEED_SEARCH and KEY_NEED_VIEW.
Fix the logic in the unlikely case when both MAY_READ and
MAY_WRITE are needed. Validate access permission field for valid
contents.
Signed-off-by: Zoran Markovic <zmarkovic@sierrawireless.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
---
security/smack/smack_lsm.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 340fc30..77e405f 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4326,6 +4326,12 @@ static int smack_key_permission(key_ref_t key_ref,
int request = 0;
int rc;
+ /*
+ * Validate requested permissions
+ */
+ if (perm & ~KEY_NEED_ALL)
+ return -EINVAL;
+
keyp = key_ref_to_ptr(key_ref);
if (keyp == NULL)
return -EINVAL;
@@ -4349,10 +4355,10 @@ static int smack_key_permission(key_ref_t key_ref,
ad.a.u.key_struct.key = keyp->serial;
ad.a.u.key_struct.key_desc = keyp->description;
#endif
- if (perm & KEY_NEED_READ)
- request = MAY_READ;
+ if (perm & (KEY_NEED_READ | KEY_NEED_SEARCH | KEY_NEED_VIEW))
+ request |= MAY_READ;
if (perm & (KEY_NEED_WRITE | KEY_NEED_LINK | KEY_NEED_SETATTR))
- request = MAY_WRITE;
+ request |= MAY_WRITE;
rc = smk_access(tkp, keyp->security, request, &ad);
rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
return rc;
--
2.7.4
next reply other threads:[~2018-10-17 23:23 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-17 23:25 Zoran Markovic [this message]
2018-11-27 20:18 ` [RFC PATCH] smack: fix access permissions for keyring Casey Schaufler
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