diff options
Diffstat (limited to 'security/selinux/selinuxfs.c')
| -rw-r--r-- | security/selinux/selinuxfs.c | 2177 |
1 files changed, 2177 insertions, 0 deletions
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c new file mode 100644 index 0000000000..6fa6402632 --- /dev/null +++ b/security/selinux/selinuxfs.c @@ -0,0 +1,2177 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Updated: Karl MacMillan <kmacmillan@tresys.com> + * + * Added conditional policy language extensions + * + * Updated: Hewlett-Packard <paul@paul-moore.com> + * + * Added support for the policy capability bitmap + * + * Copyright (C) 2007 Hewlett-Packard Development Company, L.P. + * Copyright (C) 2003 - 2004 Tresys Technology, LLC + * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> + */ + +#include <linux/kernel.h> +#include <linux/pagemap.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/fs.h> +#include <linux/fs_context.h> +#include <linux/mount.h> +#include <linux/mutex.h> +#include <linux/namei.h> +#include <linux/init.h> +#include <linux/string.h> +#include <linux/security.h> +#include <linux/major.h> +#include <linux/seq_file.h> +#include <linux/percpu.h> +#include <linux/audit.h> +#include <linux/uaccess.h> +#include <linux/kobject.h> +#include <linux/ctype.h> + +/* selinuxfs pseudo filesystem for exporting the security policy API. + Based on the proc code and the fs/nfsd/nfsctl.c code. */ + +#include "flask.h" +#include "avc.h" +#include "avc_ss.h" +#include "security.h" +#include "objsec.h" +#include "conditional.h" +#include "ima.h" + +enum sel_inos { + SEL_ROOT_INO = 2, + SEL_LOAD, /* load policy */ + SEL_ENFORCE, /* get or set enforcing status */ + SEL_CONTEXT, /* validate context */ + SEL_ACCESS, /* compute access decision */ + SEL_CREATE, /* compute create labeling decision */ + SEL_RELABEL, /* compute relabeling decision */ + SEL_USER, /* compute reachable user contexts */ + SEL_POLICYVERS, /* return policy version for this kernel */ + SEL_COMMIT_BOOLS, /* commit new boolean values */ + SEL_MLS, /* return if MLS policy is enabled */ + SEL_DISABLE, /* disable SELinux until next reboot */ + SEL_MEMBER, /* compute polyinstantiation membership decision */ + SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */ + SEL_COMPAT_NET, /* whether to use old compat network packet controls */ + SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */ + SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */ + SEL_STATUS, /* export current status using mmap() */ + SEL_POLICY, /* allow userspace to read the in kernel policy */ + SEL_VALIDATE_TRANS, /* compute validatetrans decision */ + SEL_INO_NEXT, /* The next inode number to use */ +}; + +struct selinux_fs_info { + struct dentry *bool_dir; + unsigned int bool_num; + char **bool_pending_names; + int *bool_pending_values; + struct dentry *class_dir; + unsigned long last_class_ino; + bool policy_opened; + struct dentry *policycap_dir; + unsigned long last_ino; + struct super_block *sb; +}; + +static int selinux_fs_info_create(struct super_block *sb) +{ + struct selinux_fs_info *fsi; + + fsi = kzalloc(sizeof(*fsi), GFP_KERNEL); + if (!fsi) + return -ENOMEM; + + fsi->last_ino = SEL_INO_NEXT - 1; + fsi->sb = sb; + sb->s_fs_info = fsi; + return 0; +} + +static void selinux_fs_info_free(struct super_block *sb) +{ + struct selinux_fs_info *fsi = sb->s_fs_info; + unsigned int i; + + if (fsi) { + for (i = 0; i < fsi->bool_num; i++) + kfree(fsi->bool_pending_names[i]); + kfree(fsi->bool_pending_names); + kfree(fsi->bool_pending_values); + } + kfree(sb->s_fs_info); + sb->s_fs_info = NULL; +} + +#define SEL_INITCON_INO_OFFSET 0x01000000 +#define SEL_BOOL_INO_OFFSET 0x02000000 +#define SEL_CLASS_INO_OFFSET 0x04000000 +#define SEL_POLICYCAP_INO_OFFSET 0x08000000 +#define SEL_INO_MASK 0x00ffffff + +#define BOOL_DIR_NAME "booleans" +#define CLASS_DIR_NAME "class" +#define POLICYCAP_DIR_NAME "policy_capabilities" + +#define TMPBUFLEN 12 +static ssize_t sel_read_enforce(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char tmpbuf[TMPBUFLEN]; + ssize_t length; + + length = scnprintf(tmpbuf, TMPBUFLEN, "%d", + enforcing_enabled()); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +#ifdef CONFIG_SECURITY_SELINUX_DEVELOP +static ssize_t sel_write_enforce(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) + +{ + char *page = NULL; + ssize_t length; + int scan_value; + bool old_value, new_value; + + if (count >= PAGE_SIZE) + return -ENOMEM; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user_nul(buf, count); + if (IS_ERR(page)) + return PTR_ERR(page); + + length = -EINVAL; + if (sscanf(page, "%d", &scan_value) != 1) + goto out; + + new_value = !!scan_value; + + old_value = enforcing_enabled(); + if (new_value != old_value) { + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__SETENFORCE, + NULL); + if (length) + goto out; + audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS, + "enforcing=%d old_enforcing=%d auid=%u ses=%u" + " enabled=1 old-enabled=1 lsm=selinux res=1", + new_value, old_value, + from_kuid(&init_user_ns, audit_get_loginuid(current)), + audit_get_sessionid(current)); + enforcing_set(new_value); + if (new_value) + avc_ss_reset(0); + selnl_notify_setenforce(new_value); + selinux_status_update_setenforce(new_value); + if (!new_value) + call_blocking_lsm_notifier(LSM_POLICY_CHANGE, NULL); + + selinux_ima_measure_state(); + } + length = count; +out: + kfree(page); + return length; +} +#else +#define sel_write_enforce NULL +#endif + +static const struct file_operations sel_enforce_ops = { + .read = sel_read_enforce, + .write = sel_write_enforce, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char tmpbuf[TMPBUFLEN]; + ssize_t length; + ino_t ino = file_inode(filp)->i_ino; + int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ? + security_get_reject_unknown() : + !security_get_allow_unknown(); + + length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static const struct file_operations sel_handle_unknown_ops = { + .read = sel_read_handle_unknown, + .llseek = generic_file_llseek, +}; + +static int sel_open_handle_status(struct inode *inode, struct file *filp) +{ + struct page *status = selinux_kernel_status_page(); + + if (!status) + return -ENOMEM; + + filp->private_data = status; + + return 0; +} + +static ssize_t sel_read_handle_status(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + struct page *status = filp->private_data; + + BUG_ON(!status); + + return simple_read_from_buffer(buf, count, ppos, + page_address(status), + sizeof(struct selinux_kernel_status)); +} + +static int sel_mmap_handle_status(struct file *filp, + struct vm_area_struct *vma) +{ + struct page *status = filp->private_data; + unsigned long size = vma->vm_end - vma->vm_start; + + BUG_ON(!status); + + /* only allows one page from the head */ + if (vma->vm_pgoff > 0 || size != PAGE_SIZE) + return -EIO; + /* disallow writable mapping */ + if (vma->vm_flags & VM_WRITE) + return -EPERM; + /* disallow mprotect() turns it into writable */ + vm_flags_clear(vma, VM_MAYWRITE); + + return remap_pfn_range(vma, vma->vm_start, + page_to_pfn(status), + size, vma->vm_page_prot); +} + +static const struct file_operations sel_handle_status_ops = { + .open = sel_open_handle_status, + .read = sel_read_handle_status, + .mmap = sel_mmap_handle_status, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_write_disable(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) + +{ + char *page; + ssize_t length; + int new_value; + + if (count >= PAGE_SIZE) + return -ENOMEM; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user_nul(buf, count); + if (IS_ERR(page)) + return PTR_ERR(page); + + if (sscanf(page, "%d", &new_value) != 1) { + length = -EINVAL; + goto out; + } + length = count; + + if (new_value) { + pr_err("SELinux: https://github.com/SELinuxProject/selinux-kernel/wiki/DEPRECATE-runtime-disable\n"); + pr_err("SELinux: Runtime disable is not supported, use selinux=0 on the kernel cmdline.\n"); + } + +out: + kfree(page); + return length; +} + +static const struct file_operations sel_disable_ops = { + .write = sel_write_disable, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_read_policyvers(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char tmpbuf[TMPBUFLEN]; + ssize_t length; + + length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static const struct file_operations sel_policyvers_ops = { + .read = sel_read_policyvers, + .llseek = generic_file_llseek, +}; + +/* declaration for sel_write_load */ +static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_dir, + unsigned int *bool_num, char ***bool_pending_names, + int **bool_pending_values); +static int sel_make_classes(struct selinux_policy *newpolicy, + struct dentry *class_dir, + unsigned long *last_class_ino); + +/* declaration for sel_make_class_dirs */ +static struct dentry *sel_make_dir(struct dentry *dir, const char *name, + unsigned long *ino); + +/* declaration for sel_make_policy_nodes */ +static struct dentry *sel_make_disconnected_dir(struct super_block *sb, + unsigned long *ino); + +/* declaration for sel_make_policy_nodes */ +static void sel_remove_entries(struct dentry *de); + +static ssize_t sel_read_mls(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char tmpbuf[TMPBUFLEN]; + ssize_t length; + + length = scnprintf(tmpbuf, TMPBUFLEN, "%d", + security_mls_enabled()); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static const struct file_operations sel_mls_ops = { + .read = sel_read_mls, + .llseek = generic_file_llseek, +}; + +struct policy_load_memory { + size_t len; + void *data; +}; + +static int sel_open_policy(struct inode *inode, struct file *filp) +{ + struct selinux_fs_info *fsi = inode->i_sb->s_fs_info; + struct policy_load_memory *plm = NULL; + int rc; + + BUG_ON(filp->private_data); + + mutex_lock(&selinux_state.policy_mutex); + + rc = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL); + if (rc) + goto err; + + rc = -EBUSY; + if (fsi->policy_opened) + goto err; + + rc = -ENOMEM; + plm = kzalloc(sizeof(*plm), GFP_KERNEL); + if (!plm) + goto err; + + rc = security_read_policy(&plm->data, &plm->len); + if (rc) + goto err; + + if ((size_t)i_size_read(inode) != plm->len) { + inode_lock(inode); + i_size_write(inode, plm->len); + inode_unlock(inode); + } + + fsi->policy_opened = 1; + + filp->private_data = plm; + + mutex_unlock(&selinux_state.policy_mutex); + + return 0; +err: + mutex_unlock(&selinux_state.policy_mutex); + + if (plm) + vfree(plm->data); + kfree(plm); + return rc; +} + +static int sel_release_policy(struct inode *inode, struct file *filp) +{ + struct selinux_fs_info *fsi = inode->i_sb->s_fs_info; + struct policy_load_memory *plm = filp->private_data; + + BUG_ON(!plm); + + fsi->policy_opened = 0; + + vfree(plm->data); + kfree(plm); + + return 0; +} + +static ssize_t sel_read_policy(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + struct policy_load_memory *plm = filp->private_data; + int ret; + + ret = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL); + if (ret) + return ret; + + return simple_read_from_buffer(buf, count, ppos, plm->data, plm->len); +} + +static vm_fault_t sel_mmap_policy_fault(struct vm_fault *vmf) +{ + struct policy_load_memory *plm = vmf->vma->vm_file->private_data; + unsigned long offset; + struct page *page; + + if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE)) + return VM_FAULT_SIGBUS; + + offset = vmf->pgoff << PAGE_SHIFT; + if (offset >= roundup(plm->len, PAGE_SIZE)) + return VM_FAULT_SIGBUS; + + page = vmalloc_to_page(plm->data + offset); + get_page(page); + + vmf->page = page; + + return 0; +} + +static const struct vm_operations_struct sel_mmap_policy_ops = { + .fault = sel_mmap_policy_fault, + .page_mkwrite = sel_mmap_policy_fault, +}; + +static int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma) +{ + if (vma->vm_flags & VM_SHARED) { + /* do not allow mprotect to make mapping writable */ + vm_flags_clear(vma, VM_MAYWRITE); + + if (vma->vm_flags & VM_WRITE) + return -EACCES; + } + + vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP); + vma->vm_ops = &sel_mmap_policy_ops; + + return 0; +} + +static const struct file_operations sel_policy_ops = { + .open = sel_open_policy, + .read = sel_read_policy, + .mmap = sel_mmap_policy, + .release = sel_release_policy, + .llseek = generic_file_llseek, +}; + +static void sel_remove_old_bool_data(unsigned int bool_num, char **bool_names, + int *bool_values) +{ + u32 i; + + /* bool_dir cleanup */ + for (i = 0; i < bool_num; i++) + kfree(bool_names[i]); + kfree(bool_names); + kfree(bool_values); +} + +static int sel_make_policy_nodes(struct selinux_fs_info *fsi, + struct selinux_policy *newpolicy) +{ + int ret = 0; + struct dentry *tmp_parent, *tmp_bool_dir, *tmp_class_dir, *old_dentry; + unsigned int tmp_bool_num, old_bool_num; + char **tmp_bool_names, **old_bool_names; + int *tmp_bool_values, *old_bool_values; + unsigned long tmp_ino = fsi->last_ino; /* Don't increment last_ino in this function */ + + tmp_parent = sel_make_disconnected_dir(fsi->sb, &tmp_ino); + if (IS_ERR(tmp_parent)) + return PTR_ERR(tmp_parent); + + tmp_ino = fsi->bool_dir->d_inode->i_ino - 1; /* sel_make_dir will increment and set */ + tmp_bool_dir = sel_make_dir(tmp_parent, BOOL_DIR_NAME, &tmp_ino); + if (IS_ERR(tmp_bool_dir)) { + ret = PTR_ERR(tmp_bool_dir); + goto out; + } + + tmp_ino = fsi->class_dir->d_inode->i_ino - 1; /* sel_make_dir will increment and set */ + tmp_class_dir = sel_make_dir(tmp_parent, CLASS_DIR_NAME, &tmp_ino); + if (IS_ERR(tmp_class_dir)) { + ret = PTR_ERR(tmp_class_dir); + goto out; + } + + ret = sel_make_bools(newpolicy, tmp_bool_dir, &tmp_bool_num, + &tmp_bool_names, &tmp_bool_values); + if (ret) + goto out; + + ret = sel_make_classes(newpolicy, tmp_class_dir, + &fsi->last_class_ino); + if (ret) + goto out; + + /* booleans */ + old_dentry = fsi->bool_dir; + lock_rename(tmp_bool_dir, old_dentry); + d_exchange(tmp_bool_dir, fsi->bool_dir); + + old_bool_num = fsi->bool_num; + old_bool_names = fsi->bool_pending_names; + old_bool_values = fsi->bool_pending_values; + + fsi->bool_num = tmp_bool_num; + fsi->bool_pending_names = tmp_bool_names; + fsi->bool_pending_values = tmp_bool_values; + + sel_remove_old_bool_data(old_bool_num, old_bool_names, old_bool_values); + + fsi->bool_dir = tmp_bool_dir; + unlock_rename(tmp_bool_dir, old_dentry); + + /* classes */ + old_dentry = fsi->class_dir; + lock_rename(tmp_class_dir, old_dentry); + d_exchange(tmp_class_dir, fsi->class_dir); + fsi->class_dir = tmp_class_dir; + unlock_rename(tmp_class_dir, old_dentry); + +out: + /* Since the other temporary dirs are children of tmp_parent + * this will handle all the cleanup in the case of a failure before + * the swapover + */ + sel_remove_entries(tmp_parent); + dput(tmp_parent); /* d_genocide() only handles the children */ + + return ret; +} + +static ssize_t sel_write_load(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) + +{ + struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info; + struct selinux_load_state load_state; + ssize_t length; + void *data = NULL; + + mutex_lock(&selinux_state.policy_mutex); + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__LOAD_POLICY, NULL); + if (length) + goto out; + + /* No partial writes. */ + length = -EINVAL; + if (*ppos != 0) + goto out; + + length = -ENOMEM; + data = vmalloc(count); + if (!data) + goto out; + + length = -EFAULT; + if (copy_from_user(data, buf, count) != 0) + goto out; + + length = security_load_policy(data, count, &load_state); + if (length) { + pr_warn_ratelimited("SELinux: failed to load policy\n"); + goto out; + } + + length = sel_make_policy_nodes(fsi, load_state.policy); + if (length) { + pr_warn_ratelimited("SELinux: failed to initialize selinuxfs\n"); + selinux_policy_cancel(&load_state); + goto out; + } + + selinux_policy_commit(&load_state); + + length = count; + + audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_POLICY_LOAD, + "auid=%u ses=%u lsm=selinux res=1", + from_kuid(&init_user_ns, audit_get_loginuid(current)), + audit_get_sessionid(current)); +out: + mutex_unlock(&selinux_state.policy_mutex); + vfree(data); + return length; +} + +static const struct file_operations sel_load_ops = { + .write = sel_write_load, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_write_context(struct file *file, char *buf, size_t size) +{ + char *canon = NULL; + u32 sid, len; + ssize_t length; + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__CHECK_CONTEXT, NULL); + if (length) + goto out; + + length = security_context_to_sid(buf, size, &sid, GFP_KERNEL); + if (length) + goto out; + + length = security_sid_to_context(sid, &canon, &len); + if (length) + goto out; + + length = -ERANGE; + if (len > SIMPLE_TRANSACTION_LIMIT) { + pr_err("SELinux: %s: context size (%u) exceeds " + "payload max\n", __func__, len); + goto out; + } + + memcpy(buf, canon, len); + length = len; +out: + kfree(canon); + return length; +} + +static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char tmpbuf[TMPBUFLEN]; + ssize_t length; + + length = scnprintf(tmpbuf, TMPBUFLEN, "%u", + checkreqprot_get()); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char *page; + ssize_t length; + unsigned int new_value; + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__SETCHECKREQPROT, + NULL); + if (length) + return length; + + if (count >= PAGE_SIZE) + return -ENOMEM; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user_nul(buf, count); + if (IS_ERR(page)) + return PTR_ERR(page); + + if (sscanf(page, "%u", &new_value) != 1) { + length = -EINVAL; + goto out; + } + length = count; + + if (new_value) { + char comm[sizeof(current->comm)]; + + memcpy(comm, current->comm, sizeof(comm)); + pr_err("SELinux: %s (%d) set checkreqprot to 1. This is no longer supported.\n", + comm, current->pid); + } + + selinux_ima_measure_state(); + +out: + kfree(page); + return length; +} +static const struct file_operations sel_checkreqprot_ops = { + .read = sel_read_checkreqprot, + .write = sel_write_checkreqprot, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_write_validatetrans(struct file *file, + const char __user *buf, + size_t count, loff_t *ppos) +{ + char *oldcon = NULL, *newcon = NULL, *taskcon = NULL; + char *req = NULL; + u32 osid, nsid, tsid; + u16 tclass; + int rc; + + rc = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__VALIDATE_TRANS, NULL); + if (rc) + goto out; + + rc = -ENOMEM; + if (count >= PAGE_SIZE) + goto out; + + /* No partial writes. */ + rc = -EINVAL; + if (*ppos != 0) + goto out; + + req = memdup_user_nul(buf, count); + if (IS_ERR(req)) { + rc = PTR_ERR(req); + req = NULL; + goto out; + } + + rc = -ENOMEM; + oldcon = kzalloc(count + 1, GFP_KERNEL); + if (!oldcon) + goto out; + + newcon = kzalloc(count + 1, GFP_KERNEL); + if (!newcon) + goto out; + + taskcon = kzalloc(count + 1, GFP_KERNEL); + if (!taskcon) + goto out; + + rc = -EINVAL; + if (sscanf(req, "%s %s %hu %s", oldcon, newcon, &tclass, taskcon) != 4) + goto out; + + rc = security_context_str_to_sid(oldcon, &osid, GFP_KERNEL); + if (rc) + goto out; + + rc = security_context_str_to_sid(newcon, &nsid, GFP_KERNEL); + if (rc) + goto out; + + rc = security_context_str_to_sid(taskcon, &tsid, GFP_KERNEL); + if (rc) + goto out; + + rc = security_validate_transition_user(osid, nsid, tsid, tclass); + if (!rc) + rc = count; +out: + kfree(req); + kfree(oldcon); + kfree(newcon); + kfree(taskcon); + return rc; +} + +static const struct file_operations sel_transition_ops = { + .write = sel_write_validatetrans, + .llseek = generic_file_llseek, +}; + +/* + * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c + */ +static ssize_t sel_write_access(struct file *file, char *buf, size_t size); +static ssize_t sel_write_create(struct file *file, char *buf, size_t size); +static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size); +static ssize_t sel_write_user(struct file *file, char *buf, size_t size); +static ssize_t sel_write_member(struct file *file, char *buf, size_t size); + +static ssize_t (*const write_op[])(struct file *, char *, size_t) = { + [SEL_ACCESS] = sel_write_access, + [SEL_CREATE] = sel_write_create, + [SEL_RELABEL] = sel_write_relabel, + [SEL_USER] = sel_write_user, + [SEL_MEMBER] = sel_write_member, + [SEL_CONTEXT] = sel_write_context, +}; + +static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos) +{ + ino_t ino = file_inode(file)->i_ino; + char *data; + ssize_t rv; + + if (ino >= ARRAY_SIZE(write_op) || !write_op[ino]) + return -EINVAL; + + data = simple_transaction_get(file, buf, size); + if (IS_ERR(data)) + return PTR_ERR(data); + + rv = write_op[ino](file, data, size); + if (rv > 0) { + simple_transaction_set(file, rv); + rv = size; + } + return rv; +} + +static const struct file_operations transaction_ops = { + .write = selinux_transaction_write, + .read = simple_transaction_read, + .release = simple_transaction_release, + .llseek = generic_file_llseek, +}; + +/* + * payload - write methods + * If the method has a response, the response should be put in buf, + * and the length returned. Otherwise return 0 or and -error. + */ + +static ssize_t sel_write_access(struct file *file, char *buf, size_t size) +{ + char *scon = NULL, *tcon = NULL; + u32 ssid, tsid; + u16 tclass; + struct av_decision avd; + ssize_t length; + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__COMPUTE_AV, NULL); + if (length) + goto out; + + length = -ENOMEM; + scon = kzalloc(size + 1, GFP_KERNEL); + if (!scon) + goto out; + + length = -ENOMEM; + tcon = kzalloc(size + 1, GFP_KERNEL); + if (!tcon) + goto out; + + length = -EINVAL; + if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3) + goto out; + + length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL); + if (length) + goto out; + + length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL); + if (length) + goto out; + + security_compute_av_user(ssid, tsid, tclass, &avd); + + length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, + "%x %x %x %x %u %x", + avd.allowed, 0xffffffff, + avd.auditallow, avd.auditdeny, + avd.seqno, avd.flags); +out: + kfree(tcon); + kfree(scon); + return length; +} + +static ssize_t sel_write_create(struct file *file, char *buf, size_t size) +{ + char *scon = NULL, *tcon = NULL; + char *namebuf = NULL, *objname = NULL; + u32 ssid, tsid, newsid; + u16 tclass; + ssize_t length; + char *newcon = NULL; + u32 len; + int nargs; + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__COMPUTE_CREATE, + NULL); + if (length) + goto out; + + length = -ENOMEM; + scon = kzalloc(size + 1, GFP_KERNEL); + if (!scon) + goto out; + + length = -ENOMEM; + tcon = kzalloc(size + 1, GFP_KERNEL); + if (!tcon) + goto out; + + length = -ENOMEM; + namebuf = kzalloc(size + 1, GFP_KERNEL); + if (!namebuf) + goto out; + + length = -EINVAL; + nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf); + if (nargs < 3 || nargs > 4) + goto out; + if (nargs == 4) { + /* + * If and when the name of new object to be queried contains + * either whitespace or multibyte characters, they shall be + * encoded based on the percentage-encoding rule. + * If not encoded, the sscanf logic picks up only left-half + * of the supplied name; split by a whitespace unexpectedly. + */ + char *r, *w; + int c1, c2; + + r = w = namebuf; + do { + c1 = *r++; + if (c1 == '+') + c1 = ' '; + else if (c1 == '%') { + c1 = hex_to_bin(*r++); + if (c1 < 0) + goto out; + c2 = hex_to_bin(*r++); + if (c2 < 0) + goto out; + c1 = (c1 << 4) | c2; + } + *w++ = c1; + } while (c1 != '\0'); + + objname = namebuf; + } + + length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL); + if (length) + goto out; + + length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL); + if (length) + goto out; + + length = security_transition_sid_user(ssid, tsid, tclass, + objname, &newsid); + if (length) + goto out; + + length = security_sid_to_context(newsid, &newcon, &len); + if (length) + goto out; + + length = -ERANGE; + if (len > SIMPLE_TRANSACTION_LIMIT) { + pr_err("SELinux: %s: context size (%u) exceeds " + "payload max\n", __func__, len); + goto out; + } + + memcpy(buf, newcon, len); + length = len; +out: + kfree(newcon); + kfree(namebuf); + kfree(tcon); + kfree(scon); + return length; +} + +static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size) +{ + char *scon = NULL, *tcon = NULL; + u32 ssid, tsid, newsid; + u16 tclass; + ssize_t length; + char *newcon = NULL; + u32 len; + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__COMPUTE_RELABEL, + NULL); + if (length) + goto out; + + length = -ENOMEM; + scon = kzalloc(size + 1, GFP_KERNEL); + if (!scon) + goto out; + + length = -ENOMEM; + tcon = kzalloc(size + 1, GFP_KERNEL); + if (!tcon) + goto out; + + length = -EINVAL; + if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3) + goto out; + + length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL); + if (length) + goto out; + + length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL); + if (length) + goto out; + + length = security_change_sid(ssid, tsid, tclass, &newsid); + if (length) + goto out; + + length = security_sid_to_context(newsid, &newcon, &len); + if (length) + goto out; + + length = -ERANGE; + if (len > SIMPLE_TRANSACTION_LIMIT) + goto out; + + memcpy(buf, newcon, len); + length = len; +out: + kfree(newcon); + kfree(tcon); + kfree(scon); + return length; +} + +static ssize_t sel_write_user(struct file *file, char *buf, size_t size) +{ + char *con = NULL, *user = NULL, *ptr; + u32 sid, *sids = NULL; + ssize_t length; + char *newcon; + int rc; + u32 i, len, nsids; + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__COMPUTE_USER, + NULL); + if (length) + goto out; + + length = -ENOMEM; + con = kzalloc(size + 1, GFP_KERNEL); + if (!con) + goto out; + + length = -ENOMEM; + user = kzalloc(size + 1, GFP_KERNEL); + if (!user) + goto out; + + length = -EINVAL; + if (sscanf(buf, "%s %s", con, user) != 2) + goto out; + + length = security_context_str_to_sid(con, &sid, GFP_KERNEL); + if (length) + goto out; + + length = security_get_user_sids(sid, user, &sids, &nsids); + if (length) + goto out; + + length = sprintf(buf, "%u", nsids) + 1; + ptr = buf + length; + for (i = 0; i < nsids; i++) { + rc = security_sid_to_context(sids[i], &newcon, &len); + if (rc) { + length = rc; + goto out; + } + if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) { + kfree(newcon); + length = -ERANGE; + goto out; + } + memcpy(ptr, newcon, len); + kfree(newcon); + ptr += len; + length += len; + } +out: + kfree(sids); + kfree(user); + kfree(con); + return length; +} + +static ssize_t sel_write_member(struct file *file, char *buf, size_t size) +{ + char *scon = NULL, *tcon = NULL; + u32 ssid, tsid, newsid; + u16 tclass; + ssize_t length; + char *newcon = NULL; + u32 len; + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__COMPUTE_MEMBER, + NULL); + if (length) + goto out; + + length = -ENOMEM; + scon = kzalloc(size + 1, GFP_KERNEL); + if (!scon) + goto out; + + length = -ENOMEM; + tcon = kzalloc(size + 1, GFP_KERNEL); + if (!tcon) + goto out; + + length = -EINVAL; + if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3) + goto out; + + length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL); + if (length) + goto out; + + length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL); + if (length) + goto out; + + length = security_member_sid(ssid, tsid, tclass, &newsid); + if (length) + goto out; + + length = security_sid_to_context(newsid, &newcon, &len); + if (length) + goto out; + + length = -ERANGE; + if (len > SIMPLE_TRANSACTION_LIMIT) { + pr_err("SELinux: %s: context size (%u) exceeds " + "payload max\n", __func__, len); + goto out; + } + + memcpy(buf, newcon, len); + length = len; +out: + kfree(newcon); + kfree(tcon); + kfree(scon); + return length; +} + +static struct inode *sel_make_inode(struct super_block *sb, umode_t mode) +{ + struct inode *ret = new_inode(sb); + + if (ret) { + ret->i_mode = mode; + ret->i_atime = ret->i_mtime = inode_set_ctime_current(ret); + } + return ret; +} + +static ssize_t sel_read_bool(struct file *filep, char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info; + char *page = NULL; + ssize_t length; + ssize_t ret; + int cur_enforcing; + unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK; + const char *name = filep->f_path.dentry->d_name.name; + + mutex_lock(&selinux_state.policy_mutex); + + ret = -EINVAL; + if (index >= fsi->bool_num || strcmp(name, + fsi->bool_pending_names[index])) + goto out_unlock; + + ret = -ENOMEM; + page = (char *)get_zeroed_page(GFP_KERNEL); + if (!page) + goto out_unlock; + + cur_enforcing = security_get_bool_value(index); + if (cur_enforcing < 0) { + ret = cur_enforcing; + goto out_unlock; + } + length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing, + fsi->bool_pending_values[index]); + mutex_unlock(&selinux_state.policy_mutex); + ret = simple_read_from_buffer(buf, count, ppos, page, length); +out_free: + free_page((unsigned long)page); + return ret; + +out_unlock: + mutex_unlock(&selinux_state.policy_mutex); + goto out_free; +} + +static ssize_t sel_write_bool(struct file *filep, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info; + char *page = NULL; + ssize_t length; + int new_value; + unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK; + const char *name = filep->f_path.dentry->d_name.name; + + if (count >= PAGE_SIZE) + return -ENOMEM; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user_nul(buf, count); + if (IS_ERR(page)) + return PTR_ERR(page); + + mutex_lock(&selinux_state.policy_mutex); + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__SETBOOL, + NULL); + if (length) + goto out; + + length = -EINVAL; + if (index >= fsi->bool_num || strcmp(name, + fsi->bool_pending_names[index])) + goto out; + + length = -EINVAL; + if (sscanf(page, "%d", &new_value) != 1) + goto out; + + if (new_value) + new_value = 1; + + fsi->bool_pending_values[index] = new_value; + length = count; + +out: + mutex_unlock(&selinux_state.policy_mutex); + kfree(page); + return length; +} + +static const struct file_operations sel_bool_ops = { + .read = sel_read_bool, + .write = sel_write_bool, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_commit_bools_write(struct file *filep, + const char __user *buf, + size_t count, loff_t *ppos) +{ + struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info; + char *page = NULL; + ssize_t length; + int new_value; + + if (count >= PAGE_SIZE) + return -ENOMEM; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user_nul(buf, count); + if (IS_ERR(page)) + return PTR_ERR(page); + + mutex_lock(&selinux_state.policy_mutex); + + length = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__SETBOOL, + NULL); + if (length) + goto out; + + length = -EINVAL; + if (sscanf(page, "%d", &new_value) != 1) + goto out; + + length = 0; + if (new_value && fsi->bool_pending_values) + length = security_set_bools(fsi->bool_num, + fsi->bool_pending_values); + + if (!length) + length = count; + +out: + mutex_unlock(&selinux_state.policy_mutex); + kfree(page); + return length; +} + +static const struct file_operations sel_commit_bools_ops = { + .write = sel_commit_bools_write, + .llseek = generic_file_llseek, +}; + +static void sel_remove_entries(struct dentry *de) +{ + d_genocide(de); + shrink_dcache_parent(de); +} + +static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_dir, + unsigned int *bool_num, char ***bool_pending_names, + int **bool_pending_values) +{ + int ret; + ssize_t len; + struct dentry *dentry = NULL; + struct inode *inode = NULL; + struct inode_security_struct *isec; + char **names = NULL, *page; + u32 i, num; + int *values = NULL; + u32 sid; + + ret = -ENOMEM; + page = (char *)get_zeroed_page(GFP_KERNEL); + if (!page) + goto out; + + ret = security_get_bools(newpolicy, &num, &names, &values); + if (ret) + goto out; + + for (i = 0; i < num; i++) { + ret = -ENOMEM; + dentry = d_alloc_name(bool_dir, names[i]); + if (!dentry) + goto out; + + ret = -ENOMEM; + inode = sel_make_inode(bool_dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR); + if (!inode) { + dput(dentry); + goto out; + } + + ret = -ENAMETOOLONG; + len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]); + if (len >= PAGE_SIZE) { + dput(dentry); + iput(inode); + goto out; + } + + isec = selinux_inode(inode); + ret = selinux_policy_genfs_sid(newpolicy, "selinuxfs", page, + SECCLASS_FILE, &sid); + if (ret) { + pr_warn_ratelimited("SELinux: no sid found, defaulting to security isid for %s\n", + page); + sid = SECINITSID_SECURITY; + } + + isec->sid = sid; + isec->initialized = LABEL_INITIALIZED; + inode->i_fop = &sel_bool_ops; + inode->i_ino = i|SEL_BOOL_INO_OFFSET; + d_add(dentry, inode); + } + *bool_num = num; + *bool_pending_names = names; + *bool_pending_values = values; + + free_page((unsigned long)page); + return 0; +out: + free_page((unsigned long)page); + + if (names) { + for (i = 0; i < num; i++) + kfree(names[i]); + kfree(names); + } + kfree(values); + sel_remove_entries(bool_dir); + + return ret; +} + +static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char tmpbuf[TMPBUFLEN]; + ssize_t length; + + length = scnprintf(tmpbuf, TMPBUFLEN, "%u", + avc_get_cache_threshold()); + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static ssize_t sel_write_avc_cache_threshold(struct file *file, + const char __user *buf, + size_t count, loff_t *ppos) + +{ + char *page; + ssize_t ret; + unsigned int new_value; + + ret = avc_has_perm(current_sid(), SECINITSID_SECURITY, + SECCLASS_SECURITY, SECURITY__SETSECPARAM, + NULL); + if (ret) + return ret; + + if (count >= PAGE_SIZE) + return -ENOMEM; + + /* No partial writes. */ + if (*ppos != 0) + return -EINVAL; + + page = memdup_user_nul(buf, count); + if (IS_ERR(page)) + return PTR_ERR(page); + + ret = -EINVAL; + if (sscanf(page, "%u", &new_value) != 1) + goto out; + + avc_set_cache_threshold(new_value); + + ret = count; +out: + kfree(page); + return ret; +} + +static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char *page; + ssize_t length; + + page = (char *)__get_free_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + + length = avc_get_hash_stats(page); + if (length >= 0) + length = simple_read_from_buffer(buf, count, ppos, page, length); + free_page((unsigned long)page); + + return length; +} + +static ssize_t sel_read_sidtab_hash_stats(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char *page; + ssize_t length; + + page = (char *)__get_free_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + + length = security_sidtab_hash_stats(page); + if (length >= 0) + length = simple_read_from_buffer(buf, count, ppos, page, + length); + free_page((unsigned long)page); + + return length; +} + +static const struct file_operations sel_sidtab_hash_stats_ops = { + .read = sel_read_sidtab_hash_stats, + .llseek = generic_file_llseek, +}; + +static const struct file_operations sel_avc_cache_threshold_ops = { + .read = sel_read_avc_cache_threshold, + .write = sel_write_avc_cache_threshold, + .llseek = generic_file_llseek, +}; + +static const struct file_operations sel_avc_hash_stats_ops = { + .read = sel_read_avc_hash_stats, + .llseek = generic_file_llseek, +}; + +#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS +static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx) +{ + int cpu; + + for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) { + if (!cpu_possible(cpu)) + continue; + *idx = cpu + 1; + return &per_cpu(avc_cache_stats, cpu); + } + (*idx)++; + return NULL; +} + +static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos) +{ + loff_t n = *pos - 1; + + if (*pos == 0) + return SEQ_START_TOKEN; + + return sel_avc_get_stat_idx(&n); +} + +static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + return sel_avc_get_stat_idx(pos); +} + +static int sel_avc_stats_seq_show(struct seq_file *seq, void *v) +{ + struct avc_cache_stats *st = v; + + if (v == SEQ_START_TOKEN) { + seq_puts(seq, + "lookups hits misses allocations reclaims frees\n"); + } else { + unsigned int lookups = st->lookups; + unsigned int misses = st->misses; + unsigned int hits = lookups - misses; + seq_printf(seq, "%u %u %u %u %u %u\n", lookups, + hits, misses, st->allocations, + st->reclaims, st->frees); + } + return 0; +} + +static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v) +{ } + +static const struct seq_operations sel_avc_cache_stats_seq_ops = { + .start = sel_avc_stats_seq_start, + .next = sel_avc_stats_seq_next, + .show = sel_avc_stats_seq_show, + .stop = sel_avc_stats_seq_stop, +}; + +static int sel_open_avc_cache_stats(struct inode *inode, struct file *file) +{ + return seq_open(file, &sel_avc_cache_stats_seq_ops); +} + +static const struct file_operations sel_avc_cache_stats_ops = { + .open = sel_open_avc_cache_stats, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; +#endif + +static int sel_make_avc_files(struct dentry *dir) +{ + struct super_block *sb = dir->d_sb; + struct selinux_fs_info *fsi = sb->s_fs_info; + unsigned int i; + static const struct tree_descr files[] = { + { "cache_threshold", + &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR }, + { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO }, +#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS + { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO }, +#endif + }; + + for (i = 0; i < ARRAY_SIZE(files); i++) { + struct inode *inode; + struct dentry *dentry; + + dentry = d_alloc_name(dir, files[i].name); + if (!dentry) + return -ENOMEM; + + inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode); + if (!inode) { + dput(dentry); + return -ENOMEM; + } + + inode->i_fop = files[i].ops; + inode->i_ino = ++fsi->last_ino; + d_add(dentry, inode); + } + + return 0; +} + +static int sel_make_ss_files(struct dentry *dir) +{ + struct super_block *sb = dir->d_sb; + struct selinux_fs_info *fsi = sb->s_fs_info; + unsigned int i; + static const struct tree_descr files[] = { + { "sidtab_hash_stats", &sel_sidtab_hash_stats_ops, S_IRUGO }, + }; + + for (i = 0; i < ARRAY_SIZE(files); i++) { + struct inode *inode; + struct dentry *dentry; + + dentry = d_alloc_name(dir, files[i].name); + if (!dentry) + return -ENOMEM; + + inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode); + if (!inode) { + dput(dentry); + return -ENOMEM; + } + + inode->i_fop = files[i].ops; + inode->i_ino = ++fsi->last_ino; + d_add(dentry, inode); + } + + return 0; +} + +static ssize_t sel_read_initcon(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + char *con; + u32 sid, len; + ssize_t ret; + + sid = file_inode(file)->i_ino&SEL_INO_MASK; + ret = security_sid_to_context(sid, &con, &len); + if (ret) + return ret; + + ret = simple_read_from_buffer(buf, count, ppos, con, len); + kfree(con); + return ret; +} + +static const struct file_operations sel_initcon_ops = { + .read = sel_read_initcon, + .llseek = generic_file_llseek, +}; + +static int sel_make_initcon_files(struct dentry *dir) +{ + unsigned int i; + + for (i = 1; i <= SECINITSID_NUM; i++) { + struct inode *inode; + struct dentry *dentry; + const char *s = security_get_initial_sid_context(i); + + if (!s) + continue; + dentry = d_alloc_name(dir, s); + if (!dentry) + return -ENOMEM; + + inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO); + if (!inode) { + dput(dentry); + return -ENOMEM; + } + + inode->i_fop = &sel_initcon_ops; + inode->i_ino = i|SEL_INITCON_INO_OFFSET; + d_add(dentry, inode); + } + + return 0; +} + +static inline unsigned long sel_class_to_ino(u16 class) +{ + return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET; +} + +static inline u16 sel_ino_to_class(unsigned long ino) +{ + return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1); +} + +static inline unsigned long sel_perm_to_ino(u16 class, u32 perm) +{ + return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET; +} + +static inline u32 sel_ino_to_perm(unsigned long ino) +{ + return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1); +} + +static ssize_t sel_read_class(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + unsigned long ino = file_inode(file)->i_ino; + char res[TMPBUFLEN]; + ssize_t len = scnprintf(res, sizeof(res), "%d", sel_ino_to_class(ino)); + return simple_read_from_buffer(buf, count, ppos, res, len); +} + +static const struct file_operations sel_class_ops = { + .read = sel_read_class, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_read_perm(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + unsigned long ino = file_inode(file)->i_ino; + char res[TMPBUFLEN]; + ssize_t len = scnprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino)); + return simple_read_from_buffer(buf, count, ppos, res, len); +} + +static const struct file_operations sel_perm_ops = { + .read = sel_read_perm, + .llseek = generic_file_llseek, +}; + +static ssize_t sel_read_policycap(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + int value; + char tmpbuf[TMPBUFLEN]; + ssize_t length; + unsigned long i_ino = file_inode(file)->i_ino; + + value = security_policycap_supported(i_ino & SEL_INO_MASK); + length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value); + + return simple_read_from_buffer(buf, count, ppos, tmpbuf, length); +} + +static const struct file_operations sel_policycap_ops = { + .read = sel_read_policycap, + .llseek = generic_file_llseek, +}; + +static int sel_make_perm_files(struct selinux_policy *newpolicy, + char *objclass, int classvalue, + struct dentry *dir) +{ + u32 i, nperms; + int rc; + char **perms; + + rc = security_get_permissions(newpolicy, objclass, &perms, &nperms); + if (rc) + return rc; + + for (i = 0; i < nperms; i++) { + struct inode *inode; + struct dentry *dentry; + + rc = -ENOMEM; + dentry = d_alloc_name(dir, perms[i]); + if (!dentry) + goto out; + + rc = -ENOMEM; + inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO); + if (!inode) { + dput(dentry); + goto out; + } + + inode->i_fop = &sel_perm_ops; + /* i+1 since perm values are 1-indexed */ + inode->i_ino = sel_perm_to_ino(classvalue, i + 1); + d_add(dentry, inode); + } + rc = 0; +out: + for (i = 0; i < nperms; i++) + kfree(perms[i]); + kfree(perms); + return rc; +} + +static int sel_make_class_dir_entries(struct selinux_policy *newpolicy, + char *classname, int index, + struct dentry *dir) +{ + struct super_block *sb = dir->d_sb; + struct selinux_fs_info *fsi = sb->s_fs_info; + struct dentry *dentry = NULL; + struct inode *inode = NULL; + + dentry = d_alloc_name(dir, "index"); + if (!dentry) + return -ENOMEM; + + inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO); + if (!inode) { + dput(dentry); + return -ENOMEM; + } + + inode->i_fop = &sel_class_ops; + inode->i_ino = sel_class_to_ino(index); + d_add(dentry, inode); + + dentry = sel_make_dir(dir, "perms", &fsi->last_class_ino); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + + return sel_make_perm_files(newpolicy, classname, index, dentry); +} + +static int sel_make_classes(struct selinux_policy *newpolicy, + struct dentry *class_dir, + unsigned long *last_class_ino) +{ + u32 i, nclasses; + int rc; + char **classes; + + rc = security_get_classes(newpolicy, &classes, &nclasses); + if (rc) + return rc; + + /* +2 since classes are 1-indexed */ + *last_class_ino = sel_class_to_ino(nclasses + 2); + + for (i = 0; i < nclasses; i++) { + struct dentry *class_name_dir; + + class_name_dir = sel_make_dir(class_dir, classes[i], + last_class_ino); + if (IS_ERR(class_name_dir)) { + rc = PTR_ERR(class_name_dir); + goto out; + } + + /* i+1 since class values are 1-indexed */ + rc = sel_make_class_dir_entries(newpolicy, classes[i], i + 1, + class_name_dir); + if (rc) + goto out; + } + rc = 0; +out: + for (i = 0; i < nclasses; i++) + kfree(classes[i]); + kfree(classes); + return rc; +} + +static int sel_make_policycap(struct selinux_fs_info *fsi) +{ + unsigned int iter; + struct dentry *dentry = NULL; + struct inode *inode = NULL; + + for (iter = 0; iter <= POLICYDB_CAP_MAX; iter++) { + if (iter < ARRAY_SIZE(selinux_policycap_names)) + dentry = d_alloc_name(fsi->policycap_dir, + selinux_policycap_names[iter]); + else + dentry = d_alloc_name(fsi->policycap_dir, "unknown"); + + if (dentry == NULL) + return -ENOMEM; + + inode = sel_make_inode(fsi->sb, S_IFREG | 0444); + if (inode == NULL) { + dput(dentry); + return -ENOMEM; + } + + inode->i_fop = &sel_policycap_ops; + inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET; + d_add(dentry, inode); + } + + return 0; +} + +static struct dentry *sel_make_dir(struct dentry *dir, const char *name, + unsigned long *ino) +{ + struct dentry *dentry = d_alloc_name(dir, name); + struct inode *inode; + + if (!dentry) + return ERR_PTR(-ENOMEM); + + inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO); + if (!inode) { + dput(dentry); + return ERR_PTR(-ENOMEM); + } + + inode->i_op = &simple_dir_inode_operations; + inode->i_fop = &simple_dir_operations; + inode->i_ino = ++(*ino); + /* directory inodes start off with i_nlink == 2 (for "." entry) */ + inc_nlink(inode); + d_add(dentry, inode); + /* bump link count on parent directory, too */ + inc_nlink(d_inode(dir)); + + return dentry; +} + +static struct dentry *sel_make_disconnected_dir(struct super_block *sb, + unsigned long *ino) +{ + struct inode *inode = sel_make_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO); + + if (!inode) + return ERR_PTR(-ENOMEM); + + inode->i_op = &simple_dir_inode_operations; + inode->i_fop = &simple_dir_operations; + inode->i_ino = ++(*ino); + /* directory inodes start off with i_nlink == 2 (for "." entry) */ + inc_nlink(inode); + return d_obtain_alias(inode); +} + +#define NULL_FILE_NAME "null" + +static int sel_fill_super(struct super_block *sb, struct fs_context *fc) +{ + struct selinux_fs_info *fsi; + int ret; + struct dentry *dentry; + struct inode *inode; + struct inode_security_struct *isec; + + static const struct tree_descr selinux_files[] = { + [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR}, + [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR}, + [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO}, + [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR}, + [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO}, + [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR}, + [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO}, + [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR}, + [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO}, + [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO}, + [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO}, + [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO}, + [SEL_VALIDATE_TRANS] = {"validatetrans", &sel_transition_ops, + S_IWUGO}, + /* last one */ {""} + }; + + ret = selinux_fs_info_create(sb); + if (ret) + goto err; + + ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files); + if (ret) + goto err; + + fsi = sb->s_fs_info; + fsi->bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &fsi->last_ino); + if (IS_ERR(fsi->bool_dir)) { + ret = PTR_ERR(fsi->bool_dir); + fsi->bool_dir = NULL; + goto err; + } + + ret = -ENOMEM; + dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME); + if (!dentry) + goto err; + + ret = -ENOMEM; + inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO); + if (!inode) { + dput(dentry); + goto err; + } + + inode->i_ino = ++fsi->last_ino; + isec = selinux_inode(inode); + isec->sid = SECINITSID_DEVNULL; + isec->sclass = SECCLASS_CHR_FILE; + isec->initialized = LABEL_INITIALIZED; + + init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3)); + d_add(dentry, inode); + + dentry = sel_make_dir(sb->s_root, "avc", &fsi->last_ino); + if (IS_ERR(dentry)) { + ret = PTR_ERR(dentry); + goto err; + } + + ret = sel_make_avc_files(dentry); + if (ret) + goto err; + + dentry = sel_make_dir(sb->s_root, "ss", &fsi->last_ino); + if (IS_ERR(dentry)) { + ret = PTR_ERR(dentry); + goto err; + } + + ret = sel_make_ss_files(dentry); + if (ret) + goto err; + + dentry = sel_make_dir(sb->s_root, "initial_contexts", &fsi->last_ino); + if (IS_ERR(dentry)) { + ret = PTR_ERR(dentry); + goto err; + } + + ret = sel_make_initcon_files(dentry); + if (ret) + goto err; + + fsi->class_dir = sel_make_dir(sb->s_root, CLASS_DIR_NAME, &fsi->last_ino); + if (IS_ERR(fsi->class_dir)) { + ret = PTR_ERR(fsi->class_dir); + fsi->class_dir = NULL; + goto err; + } + + fsi->policycap_dir = sel_make_dir(sb->s_root, POLICYCAP_DIR_NAME, + &fsi->last_ino); + if (IS_ERR(fsi->policycap_dir)) { + ret = PTR_ERR(fsi->policycap_dir); + fsi->policycap_dir = NULL; + goto err; + } + + ret = sel_make_policycap(fsi); + if (ret) { + pr_err("SELinux: failed to load policy capabilities\n"); + goto err; + } + + return 0; +err: + pr_err("SELinux: %s: failed while creating inodes\n", + __func__); + + selinux_fs_info_free(sb); + + return ret; +} + +static int sel_get_tree(struct fs_context *fc) +{ + return get_tree_single(fc, sel_fill_super); +} + +static const struct fs_context_operations sel_context_ops = { + .get_tree = sel_get_tree, +}; + +static int sel_init_fs_context(struct fs_context *fc) +{ + fc->ops = &sel_context_ops; + return 0; +} + +static void sel_kill_sb(struct super_block *sb) +{ + selinux_fs_info_free(sb); + kill_litter_super(sb); +} + +static struct file_system_type sel_fs_type = { + .name = "selinuxfs", + .init_fs_context = sel_init_fs_context, + .kill_sb = sel_kill_sb, +}; + +static struct vfsmount *selinuxfs_mount __ro_after_init; +struct path selinux_null __ro_after_init; + +static int __init init_sel_fs(void) +{ + struct qstr null_name = QSTR_INIT(NULL_FILE_NAME, + sizeof(NULL_FILE_NAME)-1); + int err; + + if (!selinux_enabled_boot) + return 0; + + err = sysfs_create_mount_point(fs_kobj, "selinux"); + if (err) + return err; + + err = register_filesystem(&sel_fs_type); + if (err) { + sysfs_remove_mount_point(fs_kobj, "selinux"); + return err; + } + + selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type); + if (IS_ERR(selinuxfs_mount)) { + pr_err("selinuxfs: could not mount!\n"); + err = PTR_ERR(selinuxfs_mount); + selinuxfs_mount = NULL; + } + selinux_null.dentry = d_hash_and_lookup(selinux_null.mnt->mnt_root, + &null_name); + if (IS_ERR(selinux_null.dentry)) { + pr_err("selinuxfs: could not lookup null!\n"); + err = PTR_ERR(selinux_null.dentry); + selinux_null.dentry = NULL; + } + + return err; +} + +__initcall(init_sel_fs); |