/* 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> * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, version 2. */ #include <linux/kernel.h> #include <linux/pagemap.h> #include <linux/slab.h> #include <linux/vmalloc.h> #include <linux/fs.h> #include <linux/mutex.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" /* Policy capability filenames */ static char *policycap_names[] = { "network_peer_controls", "open_perms", "redhat1", "always_check_network" }; unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE; static int __init checkreqprot_setup(char *str) { unsigned long checkreqprot; if (!kstrtoul(str, 0, &checkreqprot)) selinux_checkreqprot = checkreqprot ? 1 : 0; return 1; } __setup("checkreqprot=", checkreqprot_setup); static DEFINE_MUTEX(sel_mutex); /* global data for booleans */ static struct dentry *bool_dir; static int bool_num; static char **bool_pending_names; static int *bool_pending_values; /* global data for classes */ static struct dentry *class_dir; static unsigned long last_class_ino; static char policy_opened; /* global data for policy capabilities */ static struct dentry *policycap_dir; /* Check whether a task is allowed to use a security operation. */ static int task_has_security(struct task_struct *tsk, u32 perms) { const struct task_security_struct *tsec; u32 sid = 0; rcu_read_lock(); tsec = __task_cred(tsk)->security; if (tsec) sid = tsec->sid; rcu_read_unlock(); if (!tsec) return -EACCES; return avc_has_perm(sid, SECINITSID_SECURITY, SECCLASS_SECURITY, perms, NULL); } 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 */ }; static unsigned long sel_last_ino = SEL_INO_NEXT - 1; #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 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", selinux_enforcing); 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 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", &new_value) != 1) goto out; new_value = !!new_value; if (new_value != selinux_enforcing) { length = task_has_security(current, SECURITY__SETENFORCE); if (length) goto out; audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS, "enforcing=%d old_enforcing=%d auid=%u ses=%u", new_value, selinux_enforcing, from_kuid(&init_user_ns, audit_get_loginuid(current)), audit_get_sessionid(current)); selinux_enforcing = new_value; if (selinux_enforcing) avc_ss_reset(0); selnl_notify_setenforce(selinux_enforcing); selinux_status_update_setenforce(selinux_enforcing); } 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 */ vma->vm_flags &= ~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, }; #ifdef CONFIG_SECURITY_SELINUX_DISABLE 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); length = -EINVAL; if (sscanf(page, "%d", &new_value) != 1) goto out; if (new_value) { length = selinux_disable(); if (length) goto out; audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS, "selinux=0 auid=%u ses=%u", from_kuid(&init_user_ns, audit_get_loginuid(current)), audit_get_sessionid(current)); } length = count; out: kfree(page); return length; } #else #define sel_write_disable NULL #endif 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(void); static int sel_make_classes(void); static int sel_make_policycap(void); /* declaration for sel_make_class_dirs */ static struct dentry *sel_make_dir(struct dentry *dir, const char *name, unsigned long *ino); 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 policy_load_memory *plm = NULL; int rc; BUG_ON(filp->private_data); mutex_lock(&sel_mutex); rc = task_has_security(current, SECURITY__READ_POLICY); if (rc) goto err; rc = -EBUSY; if (policy_opened) goto err; rc = -ENOMEM; plm = kzalloc(sizeof(*plm), GFP_KERNEL); if (!plm) goto err; if (i_size_read(inode) != security_policydb_len()) { inode_lock(inode); i_size_write(inode, security_policydb_len()); inode_unlock(inode); } rc = security_read_policy(&plm->data, &plm->len); if (rc) goto err; policy_opened = 1; filp->private_data = plm; mutex_unlock(&sel_mutex); return 0; err: mutex_unlock(&sel_mutex); if (plm) vfree(plm->data); kfree(plm); return rc; } static int sel_release_policy(struct inode *inode, struct file *filp) { struct policy_load_memory *plm = filp->private_data; BUG_ON(!plm); 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; mutex_lock(&sel_mutex); ret = task_has_security(current, SECURITY__READ_POLICY); if (ret) goto out; ret = simple_read_from_buffer(buf, count, ppos, plm->data, plm->len); out: mutex_unlock(&sel_mutex); return ret; } static int sel_mmap_policy_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { struct policy_load_memory *plm = 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 */ vma->vm_flags &= ~VM_MAYWRITE; if (vma->vm_flags & VM_WRITE) return -EACCES; } vma->vm_flags |= 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 ssize_t sel_write_load(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { ssize_t length; void *data = NULL; mutex_lock(&sel_mutex); length = task_has_security(current, SECURITY__LOAD_POLICY); if (length) goto out; /* No partial writes. */ length = -EINVAL; if (*ppos != 0) goto out; length = -EFBIG; if (count > 64 * 1024 * 1024) 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); if (length) goto out; length = sel_make_bools(); if (length) goto out1; length = sel_make_classes(); if (length) goto out1; length = sel_make_policycap(); if (length) goto out1; length = count; out1: audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_POLICY_LOAD, "policy loaded auid=%u ses=%u", from_kuid(&init_user_ns, audit_get_loginuid(current)), audit_get_sessionid(current)); out: mutex_unlock(&sel_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 = task_has_security(current, SECURITY__CHECK_CONTEXT); 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) { printk(KERN_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", selinux_checkreqprot); 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 = task_has_security(current, SECURITY__SETCHECKREQPROT); 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); length = -EINVAL; if (sscanf(page, "%u", &new_value) != 1) goto out; selinux_checkreqprot = new_value ? 1 : 0; length = count; 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 = task_has_security(current, SECURITY__VALIDATE_TRANS); if (rc) goto out; rc = -ENOMEM; if (count >= PAGE_SIZE) goto out; /* No partial writes. */ rc = -EINVAL; if (*ppos != 0) goto out; rc = -ENOMEM; req = kzalloc(count + 1, GFP_KERNEL); if (!req) goto out; rc = -EFAULT; if (copy_from_user(req, buf, count)) 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 (*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 = task_has_security(current, SECURITY__COMPUTE_AV); 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 = task_has_security(current, SECURITY__COMPUTE_CREATE); 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; splitted 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) { printk(KERN_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 = task_has_security(current, SECURITY__COMPUTE_RELABEL); 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 i, rc; u32 len, nsids; length = task_has_security(current, SECURITY__COMPUTE_USER); 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 = task_has_security(current, SECURITY__COMPUTE_MEMBER); 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) { printk(KERN_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, int mode) { struct inode *ret = new_inode(sb); if (ret) { ret->i_mode = mode; ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret); } return ret; } static ssize_t sel_read_bool(struct file *filep, char __user *buf, size_t count, loff_t *ppos) { 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(&sel_mutex); ret = -EINVAL; if (index >= bool_num || strcmp(name, bool_pending_names[index])) goto out; ret = -ENOMEM; page = (char *)get_zeroed_page(GFP_KERNEL); if (!page) goto out; cur_enforcing = security_get_bool_value(index); if (cur_enforcing < 0) { ret = cur_enforcing; goto out; } length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing, bool_pending_values[index]); ret = simple_read_from_buffer(buf, count, ppos, page, length); out: mutex_unlock(&sel_mutex); free_page((unsigned long)page); return ret; } static ssize_t sel_write_bool(struct file *filep, const char __user *buf, size_t count, loff_t *ppos) { 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; mutex_lock(&sel_mutex); length = task_has_security(current, SECURITY__SETBOOL); if (length) goto out; length = -EINVAL; if (index >= bool_num || strcmp(name, bool_pending_names[index])) goto out; length = -ENOMEM; if (count >= PAGE_SIZE) goto out; /* No partial writes. */ length = -EINVAL; if (*ppos != 0) goto out; page = memdup_user_nul(buf, count); if (IS_ERR(page)) { length = PTR_ERR(page); page = NULL; goto out; } length = -EINVAL; if (sscanf(page, "%d", &new_value) != 1) goto out; if (new_value) new_value = 1; bool_pending_values[index] = new_value; length = count; out: mutex_unlock(&sel_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) { char *page = NULL; ssize_t length; int new_value; mutex_lock(&sel_mutex); length = task_has_security(current, SECURITY__SETBOOL); if (length) goto out; length = -ENOMEM; if (count >= PAGE_SIZE) goto out; /* No partial writes. */ length = -EINVAL; if (*ppos != 0) goto out; page = memdup_user_nul(buf, count); if (IS_ERR(page)) { length = PTR_ERR(page); page = NULL; goto out; } length = -EINVAL; if (sscanf(page, "%d", &new_value) != 1) goto out; length = 0; if (new_value && bool_pending_values) length = security_set_bools(bool_num, bool_pending_values); if (!length) length = count; out: mutex_unlock(&sel_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); } #define BOOL_DIR_NAME "booleans" static int sel_make_bools(void) { int i, ret; ssize_t len; struct dentry *dentry = NULL; struct dentry *dir = bool_dir; struct inode *inode = NULL; struct inode_security_struct *isec; char **names = NULL, *page; int num; int *values = NULL; u32 sid; /* remove any existing files */ for (i = 0; i < bool_num; i++) kfree(bool_pending_names[i]); kfree(bool_pending_names); kfree(bool_pending_values); bool_num = 0; bool_pending_names = NULL; bool_pending_values = NULL; sel_remove_entries(dir); ret = -ENOMEM; page = (char *)get_zeroed_page(GFP_KERNEL); if (!page) goto out; ret = security_get_bools(&num, &names, &values); if (ret) goto out; for (i = 0; i < num; i++) { ret = -ENOMEM; dentry = d_alloc_name(dir, names[i]); if (!dentry) goto out; ret = -ENOMEM; inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR); if (!inode) goto out; ret = -ENAMETOOLONG; len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]); if (len >= PAGE_SIZE) goto out; isec = (struct inode_security_struct *)inode->i_security; ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid); if (ret) goto out; 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(dir); return ret; } #define NULL_FILE_NAME "null" struct path selinux_null; 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_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 = task_has_security(current, SECURITY__SETSECPARAM); 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_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 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); } 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_printf(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) { int i; static 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) return -ENOMEM; inode->i_fop = files[i].ops; inode->i_ino = ++sel_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) { int i; for (i = 1; i <= SECINITSID_NUM; i++) { struct inode *inode; struct dentry *dentry; dentry = d_alloc_name(dir, security_get_initial_sid_context(i)); if (!dentry) return -ENOMEM; inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO); if (!inode) 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 = snprintf(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 = snprintf(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(char *objclass, int classvalue, struct dentry *dir) { int i, rc, nperms; char **perms; rc = security_get_permissions(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) 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(char *classname, int index, struct dentry *dir) { struct dentry *dentry = NULL; struct inode *inode = NULL; int rc; dentry = d_alloc_name(dir, "index"); if (!dentry) return -ENOMEM; inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO); if (!inode) 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", &last_class_ino); if (IS_ERR(dentry)) return PTR_ERR(dentry); rc = sel_make_perm_files(classname, index, dentry); return rc; } static int sel_make_classes(void) { int rc, nclasses, i; char **classes; /* delete any existing entries */ sel_remove_entries(class_dir); rc = security_get_classes(&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(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(void) { unsigned int iter; struct dentry *dentry = NULL; struct inode *inode = NULL; sel_remove_entries(policycap_dir); for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) { if (iter < ARRAY_SIZE(policycap_names)) dentry = d_alloc_name(policycap_dir, policycap_names[iter]); else dentry = d_alloc_name(policycap_dir, "unknown"); if (dentry == NULL) return -ENOMEM; inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO); if (inode == NULL) 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 int sel_fill_super(struct super_block *sb, void *data, int silent) { int ret; struct dentry *dentry; struct inode *inode; struct inode_security_struct *isec; static 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 = simple_fill_super(sb, SELINUX_MAGIC, selinux_files); if (ret) goto err; bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &sel_last_ino); if (IS_ERR(bool_dir)) { ret = PTR_ERR(bool_dir); 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) goto err; inode->i_ino = ++sel_last_ino; isec = (struct inode_security_struct *)inode->i_security; 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); selinux_null.dentry = dentry; dentry = sel_make_dir(sb->s_root, "avc", &sel_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, "initial_contexts", &sel_last_ino); if (IS_ERR(dentry)) { ret = PTR_ERR(dentry); goto err; } ret = sel_make_initcon_files(dentry); if (ret) goto err; class_dir = sel_make_dir(sb->s_root, "class", &sel_last_ino); if (IS_ERR(class_dir)) { ret = PTR_ERR(class_dir); class_dir = NULL; goto err; } policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities", &sel_last_ino); if (IS_ERR(policycap_dir)) { ret = PTR_ERR(policycap_dir); policycap_dir = NULL; goto err; } return 0; err: printk(KERN_ERR "SELinux: %s: failed while creating inodes\n", __func__); return ret; } static struct dentry *sel_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { return mount_single(fs_type, flags, data, sel_fill_super); } static struct file_system_type sel_fs_type = { .name = "selinuxfs", .mount = sel_mount, .kill_sb = kill_litter_super, }; struct vfsmount *selinuxfs_mount; static int __init init_sel_fs(void) { int err; if (!selinux_enabled) 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)) { printk(KERN_ERR "selinuxfs: could not mount!\n"); err = PTR_ERR(selinuxfs_mount); selinuxfs_mount = NULL; } return err; } __initcall(init_sel_fs); #ifdef CONFIG_SECURITY_SELINUX_DISABLE void exit_sel_fs(void) { sysfs_remove_mount_point(fs_kobj, "selinux"); kern_unmount(selinuxfs_mount); unregister_filesystem(&sel_fs_type); } #endif