From: Paul Moore <paul@paul-moore.com>
To: Casey Schaufler <casey@schaufler-ca.com>,
John Johansen <john.johansen@canonical.com>
Cc: linux-security-module@vger.kernel.org, selinux@vger.kernel.org,
linux-audit@redhat.com
Subject: [RFC PATCH 3/4] smack: differentiate between subjective and objective task credentials
Date: Fri, 19 Feb 2021 18:29:17 -0500 [thread overview]
Message-ID: <161377735771.87807.8998552586584751981.stgit@sifl> (raw)
In-Reply-To: <161377712068.87807.12246856567527156637.stgit@sifl>
With the split of the security_task_getsecid() into subjective and
objective variants it's time to update Smack to ensure it is using
the correct task creds.
Signed-off-by: Paul Moore <paul@paul-moore.com>
---
security/smack/smack.h | 18 +++++++++++++++++-
security/smack/smack_lsm.c | 40 +++++++++++++++++++++++++++-------------
2 files changed, 44 insertions(+), 14 deletions(-)
diff --git a/security/smack/smack.h b/security/smack/smack.h
index a9768b12716bf..08f9cb80655ce 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -383,7 +383,23 @@ static inline struct smack_known *smk_of_task(const struct task_smack *tsp)
return tsp->smk_task;
}
-static inline struct smack_known *smk_of_task_struct(
+static inline struct smack_known *smk_of_task_struct_subj(
+ const struct task_struct *t)
+{
+ struct smack_known *skp;
+ const struct cred *cred;
+
+ rcu_read_lock();
+
+ cred = rcu_dereference(t->cred);
+ skp = smk_of_task(smack_cred(cred));
+
+ rcu_read_unlock();
+
+ return skp;
+}
+
+static inline struct smack_known *smk_of_task_struct_obj(
const struct task_struct *t)
{
struct smack_known *skp;
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 2bb354ef2c4a9..ea1a82742e8ba 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -159,7 +159,7 @@ static int smk_bu_current(char *note, struct smack_known *oskp,
static int smk_bu_task(struct task_struct *otp, int mode, int rc)
{
struct task_smack *tsp = smack_cred(current_cred());
- struct smack_known *smk_task = smk_of_task_struct(otp);
+ struct smack_known *smk_task = smk_of_task_struct_obj(otp);
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (rc <= 0)
@@ -479,7 +479,7 @@ static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
{
struct smack_known *skp;
- skp = smk_of_task_struct(ctp);
+ skp = smk_of_task_struct_obj(ctp);
return smk_ptrace_rule_check(current, skp, mode, __func__);
}
@@ -2031,7 +2031,7 @@ static int smk_curacc_on_task(struct task_struct *p, int access,
const char *caller)
{
struct smk_audit_info ad;
- struct smack_known *skp = smk_of_task_struct(p);
+ struct smack_known *skp = smk_of_task_struct_subj(p);
int rc;
smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
@@ -2076,15 +2076,29 @@ static int smack_task_getsid(struct task_struct *p)
}
/**
- * smack_task_getsecid - get the secid of the task
- * @p: the object task
+ * smack_task_getsecid_subj - get the subjective secid of the task
+ * @p: the task
* @secid: where to put the result
*
- * Sets the secid to contain a u32 version of the smack label.
+ * Sets the secid to contain a u32 version of the task's subjective smack label.
+ */
+static void smack_task_getsecid_subj(struct task_struct *p, u32 *secid)
+{
+ struct smack_known *skp = smk_of_task_struct_subj(p);
+
+ *secid = skp->smk_secid;
+}
+
+/**
+ * smack_task_getsecid_obj - get the objective secid of the task
+ * @p: the task
+ * @secid: where to put the result
+ *
+ * Sets the secid to contain a u32 version of the task's objective smack label.
*/
-static void smack_task_getsecid(struct task_struct *p, u32 *secid)
+static void smack_task_getsecid_obj(struct task_struct *p, u32 *secid)
{
- struct smack_known *skp = smk_of_task_struct(p);
+ struct smack_known *skp = smk_of_task_struct_obj(p);
*secid = skp->smk_secid;
}
@@ -2172,7 +2186,7 @@ static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info,
{
struct smk_audit_info ad;
struct smack_known *skp;
- struct smack_known *tkp = smk_of_task_struct(p);
+ struct smack_known *tkp = smk_of_task_struct_obj(p);
int rc;
if (!sig)
@@ -2210,7 +2224,7 @@ static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info,
static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
{
struct inode_smack *isp = smack_inode(inode);
- struct smack_known *skp = smk_of_task_struct(p);
+ struct smack_known *skp = smk_of_task_struct_obj(p);
isp->smk_inode = skp;
isp->smk_flags |= SMK_INODE_INSTANT;
@@ -3481,7 +3495,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
*/
static int smack_getprocattr(struct task_struct *p, char *name, char **value)
{
- struct smack_known *skp = smk_of_task_struct(p);
+ struct smack_known *skp = smk_of_task_struct_subj(p);
char *cp;
int slen;
@@ -4755,8 +4769,8 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(task_setpgid, smack_task_setpgid),
LSM_HOOK_INIT(task_getpgid, smack_task_getpgid),
LSM_HOOK_INIT(task_getsid, smack_task_getsid),
- LSM_HOOK_INIT(task_getsecid_subj, smack_task_getsecid),
- LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid),
+ LSM_HOOK_INIT(task_getsecid_subj, smack_task_getsecid_subj),
+ LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid_obj),
LSM_HOOK_INIT(task_setnice, smack_task_setnice),
LSM_HOOK_INIT(task_setioprio, smack_task_setioprio),
LSM_HOOK_INIT(task_getioprio, smack_task_getioprio),
next prev parent reply other threads:[~2021-02-19 23:30 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-19 23:28 [RFC PATCH 0/4] Split security_task_getsecid() into subj and obj variants Paul Moore
2021-02-19 23:29 ` [RFC PATCH 1/4] lsm: separate security_task_getsecid() into subjective and objective variants Paul Moore
2021-02-20 2:55 ` James Morris
2021-02-20 14:44 ` Paul Moore
2021-03-04 10:04 ` Jeffrey Vander Stoep
2021-03-04 23:43 ` Paul Moore
2021-03-10 8:21 ` Jeffrey Vander Stoep
2021-03-11 1:56 ` Paul Moore
2021-02-21 12:51 ` John Johansen
2021-02-21 22:09 ` Paul Moore
2021-03-04 0:44 ` Paul Moore
2021-03-10 0:28 ` Paul Moore
2021-03-10 3:09 ` John Johansen
2021-02-24 16:49 ` Mimi Zohar
2021-03-08 19:25 ` Richard Guy Briggs
2021-03-10 0:23 ` Paul Moore
2021-03-10 1:03 ` John Johansen
2021-03-11 1:55 ` Paul Moore
2021-02-19 23:29 ` [RFC PATCH 2/4] selinux: clarify task subjective and objective credentials Paul Moore
2021-02-21 12:55 ` John Johansen
2021-03-08 19:26 ` Richard Guy Briggs
2021-03-10 3:05 ` John Johansen
2021-03-11 4:32 ` Paul Moore
2021-03-17 22:56 ` Paul Moore
2021-02-19 23:29 ` Paul Moore [this message]
2021-02-21 12:56 ` [RFC PATCH 3/4] smack: differentiate between subjective and objective task credentials John Johansen
2021-03-08 19:26 ` Richard Guy Briggs
2021-03-10 1:04 ` John Johansen
2021-02-19 23:29 ` [RFC PATCH 4/4] apparmor: " Paul Moore
2021-02-21 12:57 ` John Johansen
2021-02-21 22:12 ` Paul Moore
2021-02-20 1:49 ` [RFC PATCH 0/4] Split security_task_getsecid() into subj and obj variants Casey Schaufler
2021-02-20 14:41 ` Paul Moore
2021-02-22 23:58 ` Casey Schaufler
2021-02-23 14:14 ` Mimi Zohar
2021-02-24 0:03 ` Paul Moore
2021-03-04 0:46 ` Paul Moore
2021-03-04 2:21 ` Casey Schaufler
2021-03-04 23:41 ` Paul Moore
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