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-rw-r--r--security/safesetid/Kconfig15
-rw-r--r--security/safesetid/Makefile7
-rw-r--r--security/safesetid/lsm.c285
-rw-r--r--security/safesetid/lsm.h73
-rw-r--r--security/safesetid/securityfs.c345
5 files changed, 725 insertions, 0 deletions
diff --git a/security/safesetid/Kconfig b/security/safesetid/Kconfig
new file mode 100644
index 0000000000..18b5fb9041
--- /dev/null
+++ b/security/safesetid/Kconfig
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config SECURITY_SAFESETID
+ bool "Gate setid transitions to limit CAP_SET{U/G}ID capabilities"
+ depends on SECURITY
+ select SECURITYFS
+ default n
+ help
+ SafeSetID is an LSM module that gates the setid family of syscalls to
+ restrict UID/GID transitions from a given UID/GID to only those
+ approved by a system-wide whitelist. These restrictions also prohibit
+ the given UIDs/GIDs from obtaining auxiliary privileges associated
+ with CAP_SET{U/G}ID, such as allowing a user to set up user namespace
+ UID mappings.
+
+ If you are unsure how to answer this question, answer N.
diff --git a/security/safesetid/Makefile b/security/safesetid/Makefile
new file mode 100644
index 0000000000..6b06603211
--- /dev/null
+++ b/security/safesetid/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the safesetid LSM.
+#
+
+obj-$(CONFIG_SECURITY_SAFESETID) := safesetid.o
+safesetid-y := lsm.o securityfs.o
diff --git a/security/safesetid/lsm.c b/security/safesetid/lsm.c
new file mode 100644
index 0000000000..5be5894aa0
--- /dev/null
+++ b/security/safesetid/lsm.c
@@ -0,0 +1,285 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SafeSetID Linux Security Module
+ *
+ * Author: Micah Morton <mortonm@chromium.org>
+ *
+ * Copyright (C) 2018 The Chromium OS Authors.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#define pr_fmt(fmt) "SafeSetID: " fmt
+
+#include <linux/lsm_hooks.h>
+#include <linux/module.h>
+#include <linux/ptrace.h>
+#include <linux/sched/task_stack.h>
+#include <linux/security.h>
+#include "lsm.h"
+
+/* Flag indicating whether initialization completed */
+int safesetid_initialized __initdata;
+
+struct setid_ruleset __rcu *safesetid_setuid_rules;
+struct setid_ruleset __rcu *safesetid_setgid_rules;
+
+
+/* Compute a decision for a transition from @src to @dst under @policy. */
+enum sid_policy_type _setid_policy_lookup(struct setid_ruleset *policy,
+ kid_t src, kid_t dst)
+{
+ struct setid_rule *rule;
+ enum sid_policy_type result = SIDPOL_DEFAULT;
+
+ if (policy->type == UID) {
+ hash_for_each_possible(policy->rules, rule, next, __kuid_val(src.uid)) {
+ if (!uid_eq(rule->src_id.uid, src.uid))
+ continue;
+ if (uid_eq(rule->dst_id.uid, dst.uid))
+ return SIDPOL_ALLOWED;
+ result = SIDPOL_CONSTRAINED;
+ }
+ } else if (policy->type == GID) {
+ hash_for_each_possible(policy->rules, rule, next, __kgid_val(src.gid)) {
+ if (!gid_eq(rule->src_id.gid, src.gid))
+ continue;
+ if (gid_eq(rule->dst_id.gid, dst.gid)){
+ return SIDPOL_ALLOWED;
+ }
+ result = SIDPOL_CONSTRAINED;
+ }
+ } else {
+ /* Should not reach here, report the ID as contrainsted */
+ result = SIDPOL_CONSTRAINED;
+ }
+ return result;
+}
+
+/*
+ * Compute a decision for a transition from @src to @dst under the active
+ * policy.
+ */
+static enum sid_policy_type setid_policy_lookup(kid_t src, kid_t dst, enum setid_type new_type)
+{
+ enum sid_policy_type result = SIDPOL_DEFAULT;
+ struct setid_ruleset *pol;
+
+ rcu_read_lock();
+ if (new_type == UID)
+ pol = rcu_dereference(safesetid_setuid_rules);
+ else if (new_type == GID)
+ pol = rcu_dereference(safesetid_setgid_rules);
+ else { /* Should not reach here */
+ result = SIDPOL_CONSTRAINED;
+ rcu_read_unlock();
+ return result;
+ }
+
+ if (pol) {
+ pol->type = new_type;
+ result = _setid_policy_lookup(pol, src, dst);
+ }
+ rcu_read_unlock();
+ return result;
+}
+
+static int safesetid_security_capable(const struct cred *cred,
+ struct user_namespace *ns,
+ int cap,
+ unsigned int opts)
+{
+ /* We're only interested in CAP_SETUID and CAP_SETGID. */
+ if (cap != CAP_SETUID && cap != CAP_SETGID)
+ return 0;
+
+ /*
+ * If CAP_SET{U/G}ID is currently used for a setid or setgroups syscall, we
+ * want to let it go through here; the real security check happens later, in
+ * the task_fix_set{u/g}id or task_fix_setgroups hooks.
+ */
+ if ((opts & CAP_OPT_INSETID) != 0)
+ return 0;
+
+ switch (cap) {
+ case CAP_SETUID:
+ /*
+ * If no policy applies to this task, allow the use of CAP_SETUID for
+ * other purposes.
+ */
+ if (setid_policy_lookup((kid_t){.uid = cred->uid}, INVALID_ID, UID) == SIDPOL_DEFAULT)
+ return 0;
+ /*
+ * Reject use of CAP_SETUID for functionality other than calling
+ * set*uid() (e.g. setting up userns uid mappings).
+ */
+ pr_warn("Operation requires CAP_SETUID, which is not available to UID %u for operations besides approved set*uid transitions\n",
+ __kuid_val(cred->uid));
+ return -EPERM;
+ case CAP_SETGID:
+ /*
+ * If no policy applies to this task, allow the use of CAP_SETGID for
+ * other purposes.
+ */
+ if (setid_policy_lookup((kid_t){.gid = cred->gid}, INVALID_ID, GID) == SIDPOL_DEFAULT)
+ return 0;
+ /*
+ * Reject use of CAP_SETUID for functionality other than calling
+ * set*gid() (e.g. setting up userns gid mappings).
+ */
+ pr_warn("Operation requires CAP_SETGID, which is not available to GID %u for operations besides approved set*gid transitions\n",
+ __kgid_val(cred->gid));
+ return -EPERM;
+ default:
+ /* Error, the only capabilities were checking for is CAP_SETUID/GID */
+ return 0;
+ }
+ return 0;
+}
+
+/*
+ * Check whether a caller with old credentials @old is allowed to switch to
+ * credentials that contain @new_id.
+ */
+static bool id_permitted_for_cred(const struct cred *old, kid_t new_id, enum setid_type new_type)
+{
+ bool permitted;
+
+ /* If our old creds already had this ID in it, it's fine. */
+ if (new_type == UID) {
+ if (uid_eq(new_id.uid, old->uid) || uid_eq(new_id.uid, old->euid) ||
+ uid_eq(new_id.uid, old->suid))
+ return true;
+ } else if (new_type == GID){
+ if (gid_eq(new_id.gid, old->gid) || gid_eq(new_id.gid, old->egid) ||
+ gid_eq(new_id.gid, old->sgid))
+ return true;
+ } else /* Error, new_type is an invalid type */
+ return false;
+
+ /*
+ * Transitions to new UIDs require a check against the policy of the old
+ * RUID.
+ */
+ permitted =
+ setid_policy_lookup((kid_t){.uid = old->uid}, new_id, new_type) != SIDPOL_CONSTRAINED;
+
+ if (!permitted) {
+ if (new_type == UID) {
+ pr_warn("UID transition ((%d,%d,%d) -> %d) blocked\n",
+ __kuid_val(old->uid), __kuid_val(old->euid),
+ __kuid_val(old->suid), __kuid_val(new_id.uid));
+ } else if (new_type == GID) {
+ pr_warn("GID transition ((%d,%d,%d) -> %d) blocked\n",
+ __kgid_val(old->gid), __kgid_val(old->egid),
+ __kgid_val(old->sgid), __kgid_val(new_id.gid));
+ } else /* Error, new_type is an invalid type */
+ return false;
+ }
+ return permitted;
+}
+
+/*
+ * Check whether there is either an exception for user under old cred struct to
+ * set*uid to user under new cred struct, or the UID transition is allowed (by
+ * Linux set*uid rules) even without CAP_SETUID.
+ */
+static int safesetid_task_fix_setuid(struct cred *new,
+ const struct cred *old,
+ int flags)
+{
+
+ /* Do nothing if there are no setuid restrictions for our old RUID. */
+ if (setid_policy_lookup((kid_t){.uid = old->uid}, INVALID_ID, UID) == SIDPOL_DEFAULT)
+ return 0;
+
+ if (id_permitted_for_cred(old, (kid_t){.uid = new->uid}, UID) &&
+ id_permitted_for_cred(old, (kid_t){.uid = new->euid}, UID) &&
+ id_permitted_for_cred(old, (kid_t){.uid = new->suid}, UID) &&
+ id_permitted_for_cred(old, (kid_t){.uid = new->fsuid}, UID))
+ return 0;
+
+ /*
+ * Kill this process to avoid potential security vulnerabilities
+ * that could arise from a missing allowlist entry preventing a
+ * privileged process from dropping to a lesser-privileged one.
+ */
+ force_sig(SIGKILL);
+ return -EACCES;
+}
+
+static int safesetid_task_fix_setgid(struct cred *new,
+ const struct cred *old,
+ int flags)
+{
+
+ /* Do nothing if there are no setgid restrictions for our old RGID. */
+ if (setid_policy_lookup((kid_t){.gid = old->gid}, INVALID_ID, GID) == SIDPOL_DEFAULT)
+ return 0;
+
+ if (id_permitted_for_cred(old, (kid_t){.gid = new->gid}, GID) &&
+ id_permitted_for_cred(old, (kid_t){.gid = new->egid}, GID) &&
+ id_permitted_for_cred(old, (kid_t){.gid = new->sgid}, GID) &&
+ id_permitted_for_cred(old, (kid_t){.gid = new->fsgid}, GID))
+ return 0;
+
+ /*
+ * Kill this process to avoid potential security vulnerabilities
+ * that could arise from a missing allowlist entry preventing a
+ * privileged process from dropping to a lesser-privileged one.
+ */
+ force_sig(SIGKILL);
+ return -EACCES;
+}
+
+static int safesetid_task_fix_setgroups(struct cred *new, const struct cred *old)
+{
+ int i;
+
+ /* Do nothing if there are no setgid restrictions for our old RGID. */
+ if (setid_policy_lookup((kid_t){.gid = old->gid}, INVALID_ID, GID) == SIDPOL_DEFAULT)
+ return 0;
+
+ get_group_info(new->group_info);
+ for (i = 0; i < new->group_info->ngroups; i++) {
+ if (!id_permitted_for_cred(old, (kid_t){.gid = new->group_info->gid[i]}, GID)) {
+ put_group_info(new->group_info);
+ /*
+ * Kill this process to avoid potential security vulnerabilities
+ * that could arise from a missing allowlist entry preventing a
+ * privileged process from dropping to a lesser-privileged one.
+ */
+ force_sig(SIGKILL);
+ return -EACCES;
+ }
+ }
+
+ put_group_info(new->group_info);
+ return 0;
+}
+
+static struct security_hook_list safesetid_security_hooks[] = {
+ LSM_HOOK_INIT(task_fix_setuid, safesetid_task_fix_setuid),
+ LSM_HOOK_INIT(task_fix_setgid, safesetid_task_fix_setgid),
+ LSM_HOOK_INIT(task_fix_setgroups, safesetid_task_fix_setgroups),
+ LSM_HOOK_INIT(capable, safesetid_security_capable)
+};
+
+static int __init safesetid_security_init(void)
+{
+ security_add_hooks(safesetid_security_hooks,
+ ARRAY_SIZE(safesetid_security_hooks), "safesetid");
+
+ /* Report that SafeSetID successfully initialized */
+ safesetid_initialized = 1;
+
+ return 0;
+}
+
+DEFINE_LSM(safesetid_security_init) = {
+ .init = safesetid_security_init,
+ .name = "safesetid",
+};
diff --git a/security/safesetid/lsm.h b/security/safesetid/lsm.h
new file mode 100644
index 0000000000..d346f4849c
--- /dev/null
+++ b/security/safesetid/lsm.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * SafeSetID Linux Security Module
+ *
+ * Author: Micah Morton <mortonm@chromium.org>
+ *
+ * Copyright (C) 2018 The Chromium OS Authors.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ */
+#ifndef _SAFESETID_H
+#define _SAFESETID_H
+
+#include <linux/types.h>
+#include <linux/uidgid.h>
+#include <linux/hashtable.h>
+
+/* Flag indicating whether initialization completed */
+extern int safesetid_initialized __initdata;
+
+enum sid_policy_type {
+ SIDPOL_DEFAULT, /* source ID is unaffected by policy */
+ SIDPOL_CONSTRAINED, /* source ID is affected by policy */
+ SIDPOL_ALLOWED /* target ID explicitly allowed */
+};
+
+typedef union {
+ kuid_t uid;
+ kgid_t gid;
+} kid_t;
+
+enum setid_type {
+ UID,
+ GID
+};
+
+/*
+ * Hash table entry to store safesetid policy signifying that 'src_id'
+ * can set*id to 'dst_id'.
+ */
+struct setid_rule {
+ struct hlist_node next;
+ kid_t src_id;
+ kid_t dst_id;
+
+ /* Flag to signal if rule is for UID's or GID's */
+ enum setid_type type;
+};
+
+#define SETID_HASH_BITS 8 /* 256 buckets in hash table */
+
+/* Extension of INVALID_UID/INVALID_GID for kid_t type */
+#define INVALID_ID (kid_t){.uid = INVALID_UID}
+
+struct setid_ruleset {
+ DECLARE_HASHTABLE(rules, SETID_HASH_BITS);
+ char *policy_str;
+ struct rcu_head rcu;
+
+ //Flag to signal if ruleset is for UID's or GID's
+ enum setid_type type;
+};
+
+enum sid_policy_type _setid_policy_lookup(struct setid_ruleset *policy,
+ kid_t src, kid_t dst);
+
+extern struct setid_ruleset __rcu *safesetid_setuid_rules;
+extern struct setid_ruleset __rcu *safesetid_setgid_rules;
+
+#endif /* _SAFESETID_H */
diff --git a/security/safesetid/securityfs.c b/security/safesetid/securityfs.c
new file mode 100644
index 0000000000..25310468bc
--- /dev/null
+++ b/security/safesetid/securityfs.c
@@ -0,0 +1,345 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SafeSetID Linux Security Module
+ *
+ * Author: Micah Morton <mortonm@chromium.org>
+ *
+ * Copyright (C) 2018 The Chromium OS Authors.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#define pr_fmt(fmt) "SafeSetID: " fmt
+
+#include <linux/security.h>
+#include <linux/cred.h>
+
+#include "lsm.h"
+
+static DEFINE_MUTEX(uid_policy_update_lock);
+static DEFINE_MUTEX(gid_policy_update_lock);
+
+/*
+ * In the case the input buffer contains one or more invalid IDs, the kid_t
+ * variables pointed to by @parent and @child will get updated but this
+ * function will return an error.
+ * Contents of @buf may be modified.
+ */
+static int parse_policy_line(struct file *file, char *buf,
+ struct setid_rule *rule)
+{
+ char *child_str;
+ int ret;
+ u32 parsed_parent, parsed_child;
+
+ /* Format of |buf| string should be <UID>:<UID> or <GID>:<GID> */
+ child_str = strchr(buf, ':');
+ if (child_str == NULL)
+ return -EINVAL;
+ *child_str = '\0';
+ child_str++;
+
+ ret = kstrtou32(buf, 0, &parsed_parent);
+ if (ret)
+ return ret;
+
+ ret = kstrtou32(child_str, 0, &parsed_child);
+ if (ret)
+ return ret;
+
+ if (rule->type == UID){
+ rule->src_id.uid = make_kuid(file->f_cred->user_ns, parsed_parent);
+ rule->dst_id.uid = make_kuid(file->f_cred->user_ns, parsed_child);
+ if (!uid_valid(rule->src_id.uid) || !uid_valid(rule->dst_id.uid))
+ return -EINVAL;
+ } else if (rule->type == GID){
+ rule->src_id.gid = make_kgid(file->f_cred->user_ns, parsed_parent);
+ rule->dst_id.gid = make_kgid(file->f_cred->user_ns, parsed_child);
+ if (!gid_valid(rule->src_id.gid) || !gid_valid(rule->dst_id.gid))
+ return -EINVAL;
+ } else {
+ /* Error, rule->type is an invalid type */
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static void __release_ruleset(struct rcu_head *rcu)
+{
+ struct setid_ruleset *pol =
+ container_of(rcu, struct setid_ruleset, rcu);
+ int bucket;
+ struct setid_rule *rule;
+ struct hlist_node *tmp;
+
+ hash_for_each_safe(pol->rules, bucket, tmp, rule, next)
+ kfree(rule);
+ kfree(pol->policy_str);
+ kfree(pol);
+}
+
+static void release_ruleset(struct setid_ruleset *pol){
+ call_rcu(&pol->rcu, __release_ruleset);
+}
+
+static void insert_rule(struct setid_ruleset *pol, struct setid_rule *rule)
+{
+ if (pol->type == UID)
+ hash_add(pol->rules, &rule->next, __kuid_val(rule->src_id.uid));
+ else if (pol->type == GID)
+ hash_add(pol->rules, &rule->next, __kgid_val(rule->src_id.gid));
+ else /* Error, pol->type is neither UID or GID */
+ return;
+}
+
+static int verify_ruleset(struct setid_ruleset *pol)
+{
+ int bucket;
+ struct setid_rule *rule, *nrule;
+ int res = 0;
+
+ hash_for_each(pol->rules, bucket, rule, next) {
+ if (_setid_policy_lookup(pol, rule->dst_id, INVALID_ID) == SIDPOL_DEFAULT) {
+ if (pol->type == UID) {
+ pr_warn("insecure policy detected: uid %d is constrained but transitively unconstrained through uid %d\n",
+ __kuid_val(rule->src_id.uid),
+ __kuid_val(rule->dst_id.uid));
+ } else if (pol->type == GID) {
+ pr_warn("insecure policy detected: gid %d is constrained but transitively unconstrained through gid %d\n",
+ __kgid_val(rule->src_id.gid),
+ __kgid_val(rule->dst_id.gid));
+ } else { /* pol->type is an invalid type */
+ res = -EINVAL;
+ return res;
+ }
+ res = -EINVAL;
+
+ /* fix it up */
+ nrule = kmalloc(sizeof(struct setid_rule), GFP_KERNEL);
+ if (!nrule)
+ return -ENOMEM;
+ if (pol->type == UID){
+ nrule->src_id.uid = rule->dst_id.uid;
+ nrule->dst_id.uid = rule->dst_id.uid;
+ nrule->type = UID;
+ } else { /* pol->type must be GID if we've made it to here */
+ nrule->src_id.gid = rule->dst_id.gid;
+ nrule->dst_id.gid = rule->dst_id.gid;
+ nrule->type = GID;
+ }
+ insert_rule(pol, nrule);
+ }
+ }
+ return res;
+}
+
+static ssize_t handle_policy_update(struct file *file,
+ const char __user *ubuf, size_t len, enum setid_type policy_type)
+{
+ struct setid_ruleset *pol;
+ char *buf, *p, *end;
+ int err;
+
+ pol = kmalloc(sizeof(struct setid_ruleset), GFP_KERNEL);
+ if (!pol)
+ return -ENOMEM;
+ pol->policy_str = NULL;
+ pol->type = policy_type;
+ hash_init(pol->rules);
+
+ p = buf = memdup_user_nul(ubuf, len);
+ if (IS_ERR(buf)) {
+ err = PTR_ERR(buf);
+ goto out_free_pol;
+ }
+ pol->policy_str = kstrdup(buf, GFP_KERNEL);
+ if (pol->policy_str == NULL) {
+ err = -ENOMEM;
+ goto out_free_buf;
+ }
+
+ /* policy lines, including the last one, end with \n */
+ while (*p != '\0') {
+ struct setid_rule *rule;
+
+ end = strchr(p, '\n');
+ if (end == NULL) {
+ err = -EINVAL;
+ goto out_free_buf;
+ }
+ *end = '\0';
+
+ rule = kmalloc(sizeof(struct setid_rule), GFP_KERNEL);
+ if (!rule) {
+ err = -ENOMEM;
+ goto out_free_buf;
+ }
+
+ rule->type = policy_type;
+ err = parse_policy_line(file, p, rule);
+ if (err)
+ goto out_free_rule;
+
+ if (_setid_policy_lookup(pol, rule->src_id, rule->dst_id) == SIDPOL_ALLOWED) {
+ pr_warn("bad policy: duplicate entry\n");
+ err = -EEXIST;
+ goto out_free_rule;
+ }
+
+ insert_rule(pol, rule);
+ p = end + 1;
+ continue;
+
+out_free_rule:
+ kfree(rule);
+ goto out_free_buf;
+ }
+
+ err = verify_ruleset(pol);
+ /* bogus policy falls through after fixing it up */
+ if (err && err != -EINVAL)
+ goto out_free_buf;
+
+ /*
+ * Everything looks good, apply the policy and release the old one.
+ * What we really want here is an xchg() wrapper for RCU, but since that
+ * doesn't currently exist, just use a spinlock for now.
+ */
+ if (policy_type == UID) {
+ mutex_lock(&uid_policy_update_lock);
+ pol = rcu_replace_pointer(safesetid_setuid_rules, pol,
+ lockdep_is_held(&uid_policy_update_lock));
+ mutex_unlock(&uid_policy_update_lock);
+ } else if (policy_type == GID) {
+ mutex_lock(&gid_policy_update_lock);
+ pol = rcu_replace_pointer(safesetid_setgid_rules, pol,
+ lockdep_is_held(&gid_policy_update_lock));
+ mutex_unlock(&gid_policy_update_lock);
+ } else {
+ /* Error, policy type is neither UID or GID */
+ pr_warn("error: bad policy type");
+ }
+ err = len;
+
+out_free_buf:
+ kfree(buf);
+out_free_pol:
+ if (pol)
+ release_ruleset(pol);
+ return err;
+}
+
+static ssize_t safesetid_uid_file_write(struct file *file,
+ const char __user *buf,
+ size_t len,
+ loff_t *ppos)
+{
+ if (!file_ns_capable(file, &init_user_ns, CAP_MAC_ADMIN))
+ return -EPERM;
+
+ if (*ppos != 0)
+ return -EINVAL;
+
+ return handle_policy_update(file, buf, len, UID);
+}
+
+static ssize_t safesetid_gid_file_write(struct file *file,
+ const char __user *buf,
+ size_t len,
+ loff_t *ppos)
+{
+ if (!file_ns_capable(file, &init_user_ns, CAP_MAC_ADMIN))
+ return -EPERM;
+
+ if (*ppos != 0)
+ return -EINVAL;
+
+ return handle_policy_update(file, buf, len, GID);
+}
+
+static ssize_t safesetid_file_read(struct file *file, char __user *buf,
+ size_t len, loff_t *ppos, struct mutex *policy_update_lock, struct __rcu setid_ruleset* ruleset)
+{
+ ssize_t res = 0;
+ struct setid_ruleset *pol;
+ const char *kbuf;
+
+ mutex_lock(policy_update_lock);
+ pol = rcu_dereference_protected(ruleset, lockdep_is_held(policy_update_lock));
+ if (pol) {
+ kbuf = pol->policy_str;
+ res = simple_read_from_buffer(buf, len, ppos,
+ kbuf, strlen(kbuf));
+ }
+ mutex_unlock(policy_update_lock);
+
+ return res;
+}
+
+static ssize_t safesetid_uid_file_read(struct file *file, char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ return safesetid_file_read(file, buf, len, ppos,
+ &uid_policy_update_lock, safesetid_setuid_rules);
+}
+
+static ssize_t safesetid_gid_file_read(struct file *file, char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ return safesetid_file_read(file, buf, len, ppos,
+ &gid_policy_update_lock, safesetid_setgid_rules);
+}
+
+
+
+static const struct file_operations safesetid_uid_file_fops = {
+ .read = safesetid_uid_file_read,
+ .write = safesetid_uid_file_write,
+};
+
+static const struct file_operations safesetid_gid_file_fops = {
+ .read = safesetid_gid_file_read,
+ .write = safesetid_gid_file_write,
+};
+
+static int __init safesetid_init_securityfs(void)
+{
+ int ret;
+ struct dentry *policy_dir;
+ struct dentry *uid_policy_file;
+ struct dentry *gid_policy_file;
+
+ if (!safesetid_initialized)
+ return 0;
+
+ policy_dir = securityfs_create_dir("safesetid", NULL);
+ if (IS_ERR(policy_dir)) {
+ ret = PTR_ERR(policy_dir);
+ goto error;
+ }
+
+ uid_policy_file = securityfs_create_file("uid_allowlist_policy", 0600,
+ policy_dir, NULL, &safesetid_uid_file_fops);
+ if (IS_ERR(uid_policy_file)) {
+ ret = PTR_ERR(uid_policy_file);
+ goto error;
+ }
+
+ gid_policy_file = securityfs_create_file("gid_allowlist_policy", 0600,
+ policy_dir, NULL, &safesetid_gid_file_fops);
+ if (IS_ERR(gid_policy_file)) {
+ ret = PTR_ERR(gid_policy_file);
+ goto error;
+ }
+
+
+ return 0;
+
+error:
+ securityfs_remove(policy_dir);
+ return ret;
+}
+fs_initcall(safesetid_init_securityfs);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-15 16:05:17 +0000