From: Casey Schaufler <casey@schaufler-ca.com>
To: casey@schaufler-ca.com, paul@paul-moore.com,
linux-security-module@vger.kernel.org
Cc: jmorris@namei.org, keescook@chromium.org,
john.johansen@canonical.com, penguin-kernel@i-love.sakura.ne.jp,
stephen.smalley.work@gmail.com, linux-kernel@vger.kernel.org,
linux-api@vger.kernel.org, mic@digikod.net
Subject: [PATCH v10 08/11] Smack: implement setselfattr and getselfattr hooks
Date: Fri, 28 Apr 2023 13:34:14 -0700 [thread overview]
Message-ID: <20230428203417.159874-9-casey@schaufler-ca.com> (raw)
In-Reply-To: <20230428203417.159874-1-casey@schaufler-ca.com>
Implement Smack support for security_[gs]etselfattr.
Refactor the setprocattr hook to avoid code duplication.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
security/smack/smack_lsm.c | 106 +++++++++++++++++++++++++++++++++++--
1 file changed, 101 insertions(+), 5 deletions(-)
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 0b466d3b31b7..def13357156a 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3552,6 +3552,45 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
return;
}
+/**
+ * smack_getselfattr - Smack current process attribute
+ * @attr: which attribute to fetch
+ * @ctx: buffer to receive the result
+ * @size: available size in, actual size out
+ * @flags: unused
+ *
+ * Fill the passed user space @ctx with the details of the requested
+ * attribute.
+ *
+ * Returns 1, the number of attributes, on success, an error code otherwise.
+ */
+static int smack_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx,
+ size_t *size, u32 flags)
+{
+ struct smack_known *skp = smk_of_current();
+ int total;
+ int slen;
+ int rc;
+
+ if (attr != LSM_ATTR_CURRENT)
+ return -EOPNOTSUPP;
+
+ slen = strlen(skp->smk_known) + 1;
+ total = ALIGN(slen + sizeof(*ctx), 8);
+ if (total > *size)
+ rc = -E2BIG;
+ else if (ctx)
+ rc = lsm_fill_user_ctx(ctx, skp->smk_known, slen, LSM_ID_SMACK,
+ 0);
+ else
+ rc = 1;
+
+ *size = total;
+ if (rc >= 0)
+ return 1;
+ return rc;
+}
+
/**
* smack_getprocattr - Smack process attribute access
* @p: the object task
@@ -3581,8 +3620,8 @@ static int smack_getprocattr(struct task_struct *p, const char *name, char **val
}
/**
- * smack_setprocattr - Smack process attribute setting
- * @name: the name of the attribute in /proc/.../attr
+ * do_setattr - Smack process attribute setting
+ * @attr: the ID of the attribute
* @value: the value to set
* @size: the size of the value
*
@@ -3591,7 +3630,7 @@ static int smack_getprocattr(struct task_struct *p, const char *name, char **val
*
* Returns the length of the smack label or an error code
*/
-static int smack_setprocattr(const char *name, void *value, size_t size)
+static int do_setattr(u64 attr, void *value, size_t size)
{
struct task_smack *tsp = smack_cred(current_cred());
struct cred *new;
@@ -3605,8 +3644,8 @@ static int smack_setprocattr(const char *name, void *value, size_t size)
if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
return -EINVAL;
- if (strcmp(name, "current") != 0)
- return -EINVAL;
+ if (attr != LSM_ATTR_CURRENT)
+ return -EOPNOTSUPP;
skp = smk_import_entry(value, size);
if (IS_ERR(skp))
@@ -3645,6 +3684,61 @@ static int smack_setprocattr(const char *name, void *value, size_t size)
return size;
}
+/**
+ * smack_setselfattr - Set a Smack process attribute
+ * @attr: which attribute to set
+ * @ctx: buffer containing the data
+ * @size: size of @ctx
+ * @flags: unused
+ *
+ * Fill the passed user space @ctx with the details of the requested
+ * attribute.
+ *
+ * Returns 0 on success, an error code otherwise.
+ */
+static int smack_setselfattr(unsigned int attr, struct lsm_ctx __user *ctx,
+ size_t size, u32 flags)
+{
+ struct lsm_ctx *lctx;
+ int rc;
+
+ lctx = kmalloc(size, GFP_KERNEL);
+ if (lctx == NULL)
+ return -ENOMEM;
+
+ if (copy_from_user(lctx, ctx, size))
+ rc = -EFAULT;
+ else if (lctx->ctx_len > size)
+ rc = -EINVAL;
+ else
+ rc = do_setattr(attr, lctx->ctx, lctx->ctx_len);
+
+ kfree(lctx);
+ if (rc > 0)
+ return 0;
+ return rc;
+}
+
+/**
+ * smack_setprocattr - Smack process attribute setting
+ * @name: the name of the attribute in /proc/.../attr
+ * @value: the value to set
+ * @size: the size of the value
+ *
+ * Sets the Smack value of the task. Only setting self
+ * is permitted and only with privilege
+ *
+ * Returns the length of the smack label or an error code
+ */
+static int smack_setprocattr(const char *name, void *value, size_t size)
+{
+ int attr = lsm_name_to_attr(name);
+
+ if (attr)
+ return do_setattr(attr, value, size);
+ return -EINVAL;
+}
+
/**
* smack_unix_stream_connect - Smack access on UDS
* @sock: one sock
@@ -4955,6 +5049,8 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(d_instantiate, smack_d_instantiate),
+ LSM_HOOK_INIT(getselfattr, smack_getselfattr),
+ LSM_HOOK_INIT(setselfattr, smack_setselfattr),
LSM_HOOK_INIT(getprocattr, smack_getprocattr),
LSM_HOOK_INIT(setprocattr, smack_setprocattr),
--
2.39.2
next prev parent reply other threads:[~2023-04-28 20:37 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20230428203417.159874-1-casey.ref@schaufler-ca.com>
2023-04-28 20:34 ` [PATCH v10 00/11] LSM: Three basic syscalls Casey Schaufler
2023-04-28 20:34 ` [PATCH v10 01/11] LSM: Identify modules by more than name Casey Schaufler
2023-04-28 20:34 ` [PATCH v10 02/11] LSM: Maintain a table of LSM attribute data Casey Schaufler
2023-04-28 20:34 ` [PATCH v10 03/11] proc: Use lsmids instead of lsm names for attrs Casey Schaufler
2023-06-13 18:35 ` Serge Hallyn
2023-04-28 20:34 ` [PATCH v10 04/11] LSM: syscalls for current process attributes Casey Schaufler
2023-06-07 22:32 ` [PATCH v10 4/11] " Paul Moore
2023-06-07 23:26 ` Casey Schaufler
2023-06-13 18:54 ` [PATCH v10 04/11] " Serge Hallyn
2023-04-28 20:34 ` [PATCH v10 05/11] LSM: Create lsm_list_modules system call Casey Schaufler
2023-06-13 19:02 ` Serge Hallyn
2023-04-28 20:34 ` [PATCH v10 06/11] LSM: wireup Linux Security Module syscalls Casey Schaufler
2023-04-28 20:34 ` [PATCH v10 07/11] LSM: Helpers for attribute names and filling lsm_ctx Casey Schaufler
2023-04-29 1:06 ` kernel test robot
2023-04-29 2:37 ` kernel test robot
2023-06-07 22:32 ` [PATCH v10 7/11] " Paul Moore
2023-06-15 13:19 ` [PATCH v10 07/11] " Serge Hallyn
2023-06-15 13:27 ` Serge Hallyn
2023-04-28 20:34 ` Casey Schaufler [this message]
2023-06-15 15:29 ` [PATCH v10 08/11] Smack: implement setselfattr and getselfattr hooks Serge Hallyn
2023-04-28 20:34 ` [PATCH v10 09/11] AppArmor: Add selfattr hooks Casey Schaufler
2023-04-28 20:34 ` [PATCH v10 10/11] SELinux: " Casey Schaufler
2023-06-07 22:32 ` Paul Moore
2023-06-07 23:39 ` Casey Schaufler
2023-04-28 20:34 ` [PATCH v10 11/11] LSM: selftests for Linux Security Module syscalls Casey Schaufler
2023-04-28 20:26 [PATCH v10 00/11] LSM: Three basic syscalls Casey Schaufler
2023-04-28 20:26 ` [PATCH v10 08/11] Smack: implement setselfattr and getselfattr hooks Casey Schaufler
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