* 30 May 2002: Cleanup, Robert M. Love <rml@tech9.net>
*/
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
#include <linux/audit.h>
#include <linux/capability.h>
#include <linux/mm.h>
*/
const kernel_cap_t __cap_empty_set = CAP_EMPTY_SET;
-
EXPORT_SYMBOL(__cap_empty_set);
int file_caps_enabled = 1;
}
__setup("no_file_caps", file_caps_disable);
+#ifdef CONFIG_MULTIUSER
/*
* More recent versions of libcap are available from:
*
static void warn_legacy_capability_use(void)
{
- static int warned;
- if (!warned) {
- char name[sizeof(current->comm)];
-
- printk(KERN_INFO "warning: `%s' uses 32-bit capabilities"
- " (legacy support in use)\n",
- get_task_comm(name, current));
- warned = 1;
- }
+ char name[sizeof(current->comm)];
+
+ pr_info_once("warning: `%s' uses 32-bit capabilities (legacy support in use)\n",
+ get_task_comm(name, current));
}
/*
static void warn_deprecated_v2(void)
{
- static int warned;
-
- if (!warned) {
- char name[sizeof(current->comm)];
+ char name[sizeof(current->comm)];
- printk(KERN_INFO "warning: `%s' uses deprecated v2"
- " capabilities in a way that may be insecure.\n",
- get_task_comm(name, current));
- warned = 1;
- }
+ pr_info_once("warning: `%s' uses deprecated v2 capabilities in a way that may be insecure\n",
+ get_task_comm(name, current));
}
/*
*
* An alternative would be to return an error here
* (-ERANGE), but that causes legacy applications to
- * unexpectidly fail; the capget/modify/capset aborts
+ * unexpectedly fail; the capget/modify/capset aborts
* before modification is attempted and the application
* fails.
*/
i++;
}
+ effective.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK;
+ permitted.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK;
+ inheritable.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK;
+
new = prepare_creds();
if (!new)
return -ENOMEM;
if (ret < 0)
goto error;
- audit_log_capset(pid, new, current_cred());
+ audit_log_capset(new, current_cred());
return commit_creds(new);
return has_ns_capability_noaudit(t, &init_user_ns, cap);
}
+static bool ns_capable_common(struct user_namespace *ns, int cap, bool audit)
+{
+ int capable;
+
+ if (unlikely(!cap_valid(cap))) {
+ pr_crit("capable() called with invalid cap=%u\n", cap);
+ BUG();
+ }
+
+ capable = audit ? security_capable(current_cred(), ns, cap) :
+ security_capable_noaudit(current_cred(), ns, cap);
+ if (capable == 0) {
+ current->flags |= PF_SUPERPRIV;
+ return true;
+ }
+ return false;
+}
+
/**
* ns_capable - Determine if the current task has a superior capability in effect
* @ns: The usernamespace we want the capability in
*/
bool ns_capable(struct user_namespace *ns, int cap)
{
- if (unlikely(!cap_valid(cap))) {
- printk(KERN_CRIT "capable() called with invalid cap=%u\n", cap);
- BUG();
- }
-
- if (security_capable(current_cred(), ns, cap) == 0) {
- current->flags |= PF_SUPERPRIV;
- return true;
- }
- return false;
+ return ns_capable_common(ns, cap, true);
}
EXPORT_SYMBOL(ns_capable);
+/**
+ * ns_capable_noaudit - Determine if the current task has a superior capability
+ * (unaudited) in effect
+ * @ns: The usernamespace we want the capability in
+ * @cap: The capability to be tested for
+ *
+ * Return true if the current task has the given superior capability currently
+ * available for use, false if not.
+ *
+ * This sets PF_SUPERPRIV on the task if the capability is available on the
+ * assumption that it's about to be used.
+ */
+bool ns_capable_noaudit(struct user_namespace *ns, int cap)
+{
+ return ns_capable_common(ns, cap, false);
+}
+EXPORT_SYMBOL(ns_capable_noaudit);
+
+/**
+ * capable - Determine if the current task has a superior capability in effect
+ * @cap: The capability to be tested for
+ *
+ * Return true if the current task has the given superior capability currently
+ * available for use, false if not.
+ *
+ * This sets PF_SUPERPRIV on the task if the capability is available on the
+ * assumption that it's about to be used.
+ */
+bool capable(int cap)
+{
+ return ns_capable(&init_user_ns, cap);
+}
+EXPORT_SYMBOL(capable);
+#endif /* CONFIG_MULTIUSER */
+
/**
* file_ns_capable - Determine if the file's opener had a capability in effect
* @file: The file we want to check
* This does not set PF_SUPERPRIV because the caller may not
* actually be privileged.
*/
-bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap)
+bool file_ns_capable(const struct file *file, struct user_namespace *ns,
+ int cap)
{
if (WARN_ON_ONCE(!cap_valid(cap)))
return false;
EXPORT_SYMBOL(file_ns_capable);
/**
- * capable - Determine if the current task has a superior capability in effect
- * @cap: The capability to be tested for
- *
- * Return true if the current task has the given superior capability currently
- * available for use, false if not.
+ * privileged_wrt_inode_uidgid - Do capabilities in the namespace work over the inode?
+ * @ns: The user namespace in question
+ * @inode: The inode in question
*
- * This sets PF_SUPERPRIV on the task if the capability is available on the
- * assumption that it's about to be used.
+ * Return true if the inode uid and gid are within the namespace.
*/
-bool capable(int cap)
+bool privileged_wrt_inode_uidgid(struct user_namespace *ns, const struct inode *inode)
{
- return ns_capable(&init_user_ns, cap);
+ return kuid_has_mapping(ns, inode->i_uid) &&
+ kgid_has_mapping(ns, inode->i_gid);
}
-EXPORT_SYMBOL(capable);
/**
- * nsown_capable - Check superior capability to one's own user_ns
+ * capable_wrt_inode_uidgid - Check nsown_capable and uid and gid mapped
+ * @inode: The inode in question
* @cap: The capability in question
*
- * Return true if the current task has the given superior capability
- * targeted at its own user namespace.
+ * Return true if the current task has the given capability targeted at
+ * its own user namespace and that the given inode's uid and gid are
+ * mapped into the current user namespace.
*/
-bool nsown_capable(int cap)
+bool capable_wrt_inode_uidgid(const struct inode *inode, int cap)
{
- return ns_capable(current_user_ns(), cap);
+ struct user_namespace *ns = current_user_ns();
+
+ return ns_capable(ns, cap) && privileged_wrt_inode_uidgid(ns, inode);
}
+EXPORT_SYMBOL(capable_wrt_inode_uidgid);
/**
- * inode_capable - Check superior capability over inode
- * @inode: The inode in question
- * @cap: The capability in question
- *
- * Return true if the current task has the given superior capability
- * targeted at it's own user namespace and that the given inode is owned
- * by the current user namespace or a child namespace.
- *
- * Currently we check to see if an inode is owned by the current
- * user namespace by seeing if the inode's owner maps into the
- * current user namespace.
+ * ptracer_capable - Determine if the ptracer holds CAP_SYS_PTRACE in the namespace
+ * @tsk: The task that may be ptraced
+ * @ns: The user namespace to search for CAP_SYS_PTRACE in
*
+ * Return true if the task that is ptracing the current task had CAP_SYS_PTRACE
+ * in the specified user namespace.
*/
-bool inode_capable(const struct inode *inode, int cap)
+bool ptracer_capable(struct task_struct *tsk, struct user_namespace *ns)
{
- struct user_namespace *ns = current_user_ns();
-
- return ns_capable(ns, cap) && kuid_has_mapping(ns, inode->i_uid);
+ int ret = 0; /* An absent tracer adds no restrictions */
+ const struct cred *cred;
+ rcu_read_lock();
+ cred = rcu_dereference(tsk->ptracer_cred);
+ if (cred)
+ ret = security_capable_noaudit(cred, ns, CAP_SYS_PTRACE);
+ rcu_read_unlock();
+ return (ret == 0);
}
projects / firefly-linux-kernel-4.4.55.git / blobdiff