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-rw-r--r--security/apparmor/procattr.c135
1 files changed, 135 insertions, 0 deletions
diff --git a/security/apparmor/procattr.c b/security/apparmor/procattr.c
new file mode 100644
index 0000000000..197d41f9c3
--- /dev/null
+++ b/security/apparmor/procattr.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor /proc/<pid>/attr/ interface functions
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2010 Canonical Ltd.
+ */
+
+#include "include/apparmor.h"
+#include "include/cred.h"
+#include "include/policy.h"
+#include "include/policy_ns.h"
+#include "include/domain.h"
+#include "include/procattr.h"
+
+
+/**
+ * aa_getprocattr - Return the label information for @label
+ * @label: the label to print label info about (NOT NULL)
+ * @string: Returns - string containing the label info (NOT NULL)
+ *
+ * Requires: label != NULL && string != NULL
+ *
+ * Creates a string containing the label information for @label.
+ *
+ * Returns: size of string placed in @string else error code on failure
+ */
+int aa_getprocattr(struct aa_label *label, char **string)
+{
+ struct aa_ns *ns = labels_ns(label);
+ struct aa_ns *current_ns = aa_get_current_ns();
+ int len;
+
+ if (!aa_ns_visible(current_ns, ns, true)) {
+ aa_put_ns(current_ns);
+ return -EACCES;
+ }
+
+ len = aa_label_snxprint(NULL, 0, current_ns, label,
+ FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
+ FLAG_HIDDEN_UNCONFINED);
+ AA_BUG(len < 0);
+
+ *string = kmalloc(len + 2, GFP_KERNEL);
+ if (!*string) {
+ aa_put_ns(current_ns);
+ return -ENOMEM;
+ }
+
+ len = aa_label_snxprint(*string, len + 2, current_ns, label,
+ FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
+ FLAG_HIDDEN_UNCONFINED);
+ if (len < 0) {
+ aa_put_ns(current_ns);
+ return len;
+ }
+
+ (*string)[len] = '\n';
+ (*string)[len + 1] = 0;
+
+ aa_put_ns(current_ns);
+ return len + 1;
+}
+
+/**
+ * split_token_from_name - separate a string of form <token>^<name>
+ * @op: operation being checked
+ * @args: string to parse (NOT NULL)
+ * @token: stores returned parsed token value (NOT NULL)
+ *
+ * Returns: start position of name after token else NULL on failure
+ */
+static char *split_token_from_name(const char *op, char *args, u64 *token)
+{
+ char *name;
+
+ *token = simple_strtoull(args, &name, 16);
+ if ((name == args) || *name != '^') {
+ AA_ERROR("%s: Invalid input '%s'", op, args);
+ return ERR_PTR(-EINVAL);
+ }
+
+ name++; /* skip ^ */
+ if (!*name)
+ name = NULL;
+ return name;
+}
+
+/**
+ * aa_setprocattr_changehat - handle procattr interface to change_hat
+ * @args: args received from writing to /proc/<pid>/attr/current (NOT NULL)
+ * @size: size of the args
+ * @flags: set of flags governing behavior
+ *
+ * Returns: %0 or error code if change_hat fails
+ */
+int aa_setprocattr_changehat(char *args, size_t size, int flags)
+{
+ char *hat;
+ u64 token;
+ const char *hats[16]; /* current hard limit on # of names */
+ int count = 0;
+
+ hat = split_token_from_name(OP_CHANGE_HAT, args, &token);
+ if (IS_ERR(hat))
+ return PTR_ERR(hat);
+
+ if (!hat && !token) {
+ AA_ERROR("change_hat: Invalid input, NULL hat and NULL magic");
+ return -EINVAL;
+ }
+
+ if (hat) {
+ /* set up hat name vector, args guaranteed null terminated
+ * at args[size] by setprocattr.
+ *
+ * If there are multiple hat names in the buffer each is
+ * separated by a \0. Ie. userspace writes them pre tokenized
+ */
+ char *end = args + size;
+ for (count = 0; (hat < end) && count < 16; ++count) {
+ char *next = hat + strlen(hat) + 1;
+ hats[count] = hat;
+ AA_DEBUG("%s: (pid %d) Magic 0x%llx count %d hat '%s'\n"
+ , __func__, current->pid, token, count, hat);
+ hat = next;
+ }
+ } else
+ AA_DEBUG("%s: (pid %d) Magic 0x%llx count %d Hat '%s'\n",
+ __func__, current->pid, token, count, "<NULL>");
+
+ return aa_change_hat(hats, count, token, flags);
+}