Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull security subsystem updates from James Morris:
 "In this release:

   - PKCS#7 parser for the key management subsystem from David Howells
   - appoint Kees Cook as seccomp maintainer
   - bugfixes and general maintenance across the subsystem"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (94 commits)
  X.509: Need to export x509_request_asymmetric_key()
  netlabel: shorter names for the NetLabel catmap funcs/structs
  netlabel: fix the catmap walking functions
  netlabel: fix the horribly broken catmap functions
  netlabel: fix a problem when setting bits below the previously lowest bit
  PKCS#7: X.509 certificate issuer and subject are mandatory fields in the ASN.1
  tpm: simplify code by using %*phN specifier
  tpm: Provide a generic means to override the chip returned timeouts
  tpm: missing tpm_chip_put in tpm_get_random()
  tpm: Properly clean sysfs entries in error path
  tpm: Add missing tpm_do_selftest to ST33 I2C driver
  PKCS#7: Use x509_request_asymmetric_key()
  Revert "selinux: fix the default socket labeling in sock_graft()"
  X.509: x509_request_asymmetric_keys() doesn't need string length arguments
  PKCS#7: fix sparse non static symbol warning
  KEYS: revert encrypted key change
  ima: add support for measuring and appraising firmware
  firmware_class: perform new LSM checks
  security: introduce kernel_fw_from_file hook
  PKCS#7: Missing inclusion of linux/err.h
  ...
This commit is contained in:
Linus Torvalds
2014-08-06 08:06:39 -07:00
110 changed files with 4487 additions and 841 deletions

View File

@@ -1677,7 +1677,7 @@ void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap)
audit_log_format(ab, " %s=", prefix);
CAP_FOR_EACH_U32(i) {
audit_log_format(ab, "%08x",
cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]);
cap->cap[CAP_LAST_U32 - i]);
}
}

View File

@@ -258,6 +258,10 @@ SYSCALL_DEFINE2(capset, cap_user_header_t, header, const cap_user_data_t, data)
i++;
}
effective.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK;
permitted.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK;
inheritable.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK;
new = prepare_creds();
if (!new)
return -ENOMEM;

View File

@@ -315,6 +315,15 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
goto free_ti;
tsk->stack = ti;
#ifdef CONFIG_SECCOMP
/*
* We must handle setting up seccomp filters once we're under
* the sighand lock in case orig has changed between now and
* then. Until then, filter must be NULL to avoid messing up
* the usage counts on the error path calling free_task.
*/
tsk->seccomp.filter = NULL;
#endif
setup_thread_stack(tsk, orig);
clear_user_return_notifier(tsk);
@@ -1081,6 +1090,39 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
return 0;
}
static void copy_seccomp(struct task_struct *p)
{
#ifdef CONFIG_SECCOMP
/*
* Must be called with sighand->lock held, which is common to
* all threads in the group. Holding cred_guard_mutex is not
* needed because this new task is not yet running and cannot
* be racing exec.
*/
BUG_ON(!spin_is_locked(&current->sighand->siglock));
/* Ref-count the new filter user, and assign it. */
get_seccomp_filter(current);
p->seccomp = current->seccomp;
/*
* Explicitly enable no_new_privs here in case it got set
* between the task_struct being duplicated and holding the
* sighand lock. The seccomp state and nnp must be in sync.
*/
if (task_no_new_privs(current))
task_set_no_new_privs(p);
/*
* If the parent gained a seccomp mode after copying thread
* flags and between before we held the sighand lock, we have
* to manually enable the seccomp thread flag here.
*/
if (p->seccomp.mode != SECCOMP_MODE_DISABLED)
set_tsk_thread_flag(p, TIF_SECCOMP);
#endif
}
SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr)
{
current->clear_child_tid = tidptr;
@@ -1195,7 +1237,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
goto fork_out;
ftrace_graph_init_task(p);
get_seccomp_filter(p);
rt_mutex_init_task(p);
@@ -1434,6 +1475,12 @@ static struct task_struct *copy_process(unsigned long clone_flags,
spin_lock(&current->sighand->siglock);
/*
* Copy seccomp details explicitly here, in case they were changed
* before holding sighand lock.
*/
copy_seccomp(p);
/*
* Process group and session signals need to be delivered to just the
* parent before the fork or both the parent and the child after the

View File

@@ -18,15 +18,17 @@
#include <linux/compat.h>
#include <linux/sched.h>
#include <linux/seccomp.h>
#include <linux/slab.h>
#include <linux/syscalls.h>
/* #define SECCOMP_DEBUG 1 */
#ifdef CONFIG_SECCOMP_FILTER
#include <asm/syscall.h>
#include <linux/filter.h>
#include <linux/pid.h>
#include <linux/ptrace.h>
#include <linux/security.h>
#include <linux/slab.h>
#include <linux/tracehook.h>
#include <linux/uaccess.h>
@@ -172,21 +174,24 @@ static int seccomp_check_filter(struct sock_filter *filter, unsigned int flen)
*/
static u32 seccomp_run_filters(int syscall)
{
struct seccomp_filter *f;
struct seccomp_filter *f = ACCESS_ONCE(current->seccomp.filter);
struct seccomp_data sd;
u32 ret = SECCOMP_RET_ALLOW;
/* Ensure unexpected behavior doesn't result in failing open. */
if (WARN_ON(current->seccomp.filter == NULL))
if (unlikely(WARN_ON(f == NULL)))
return SECCOMP_RET_KILL;
/* Make sure cross-thread synced filter points somewhere sane. */
smp_read_barrier_depends();
populate_seccomp_data(&sd);
/*
* All filters in the list are evaluated and the lowest BPF return
* value always takes priority (ignoring the DATA).
*/
for (f = current->seccomp.filter; f; f = f->prev) {
for (; f; f = f->prev) {
u32 cur_ret = SK_RUN_FILTER(f->prog, (void *)&sd);
if ((cur_ret & SECCOMP_RET_ACTION) < (ret & SECCOMP_RET_ACTION))
@@ -194,29 +199,159 @@ static u32 seccomp_run_filters(int syscall)
}
return ret;
}
#endif /* CONFIG_SECCOMP_FILTER */
static inline bool seccomp_may_assign_mode(unsigned long seccomp_mode)
{
BUG_ON(!spin_is_locked(&current->sighand->siglock));
if (current->seccomp.mode && current->seccomp.mode != seccomp_mode)
return false;
return true;
}
static inline void seccomp_assign_mode(struct task_struct *task,
unsigned long seccomp_mode)
{
BUG_ON(!spin_is_locked(&task->sighand->siglock));
task->seccomp.mode = seccomp_mode;
/*
* Make sure TIF_SECCOMP cannot be set before the mode (and
* filter) is set.
*/
smp_mb__before_atomic();
set_tsk_thread_flag(task, TIF_SECCOMP);
}
#ifdef CONFIG_SECCOMP_FILTER
/* Returns 1 if the parent is an ancestor of the child. */
static int is_ancestor(struct seccomp_filter *parent,
struct seccomp_filter *child)
{
/* NULL is the root ancestor. */
if (parent == NULL)
return 1;
for (; child; child = child->prev)
if (child == parent)
return 1;
return 0;
}
/**
* seccomp_attach_filter: Attaches a seccomp filter to current.
* seccomp_can_sync_threads: checks if all threads can be synchronized
*
* Expects sighand and cred_guard_mutex locks to be held.
*
* Returns 0 on success, -ve on error, or the pid of a thread which was
* either not in the correct seccomp mode or it did not have an ancestral
* seccomp filter.
*/
static inline pid_t seccomp_can_sync_threads(void)
{
struct task_struct *thread, *caller;
BUG_ON(!mutex_is_locked(&current->signal->cred_guard_mutex));
BUG_ON(!spin_is_locked(&current->sighand->siglock));
/* Validate all threads being eligible for synchronization. */
caller = current;
for_each_thread(caller, thread) {
pid_t failed;
/* Skip current, since it is initiating the sync. */
if (thread == caller)
continue;
if (thread->seccomp.mode == SECCOMP_MODE_DISABLED ||
(thread->seccomp.mode == SECCOMP_MODE_FILTER &&
is_ancestor(thread->seccomp.filter,
caller->seccomp.filter)))
continue;
/* Return the first thread that cannot be synchronized. */
failed = task_pid_vnr(thread);
/* If the pid cannot be resolved, then return -ESRCH */
if (unlikely(WARN_ON(failed == 0)))
failed = -ESRCH;
return failed;
}
return 0;
}
/**
* seccomp_sync_threads: sets all threads to use current's filter
*
* Expects sighand and cred_guard_mutex locks to be held, and for
* seccomp_can_sync_threads() to have returned success already
* without dropping the locks.
*
*/
static inline void seccomp_sync_threads(void)
{
struct task_struct *thread, *caller;
BUG_ON(!mutex_is_locked(&current->signal->cred_guard_mutex));
BUG_ON(!spin_is_locked(&current->sighand->siglock));
/* Synchronize all threads. */
caller = current;
for_each_thread(caller, thread) {
/* Skip current, since it needs no changes. */
if (thread == caller)
continue;
/* Get a task reference for the new leaf node. */
get_seccomp_filter(caller);
/*
* Drop the task reference to the shared ancestor since
* current's path will hold a reference. (This also
* allows a put before the assignment.)
*/
put_seccomp_filter(thread);
smp_store_release(&thread->seccomp.filter,
caller->seccomp.filter);
/*
* Opt the other thread into seccomp if needed.
* As threads are considered to be trust-realm
* equivalent (see ptrace_may_access), it is safe to
* allow one thread to transition the other.
*/
if (thread->seccomp.mode == SECCOMP_MODE_DISABLED) {
/*
* Don't let an unprivileged task work around
* the no_new_privs restriction by creating
* a thread that sets it up, enters seccomp,
* then dies.
*/
if (task_no_new_privs(caller))
task_set_no_new_privs(thread);
seccomp_assign_mode(thread, SECCOMP_MODE_FILTER);
}
}
}
/**
* seccomp_prepare_filter: Prepares a seccomp filter for use.
* @fprog: BPF program to install
*
* Returns 0 on success or an errno on failure.
* Returns filter on success or an ERR_PTR on failure.
*/
static long seccomp_attach_filter(struct sock_fprog *fprog)
static struct seccomp_filter *seccomp_prepare_filter(struct sock_fprog *fprog)
{
struct seccomp_filter *filter;
unsigned long fp_size = fprog->len * sizeof(struct sock_filter);
unsigned long total_insns = fprog->len;
unsigned long fp_size;
struct sock_filter *fp;
int new_len;
long ret;
if (fprog->len == 0 || fprog->len > BPF_MAXINSNS)
return -EINVAL;
for (filter = current->seccomp.filter; filter; filter = filter->prev)
total_insns += filter->prog->len + 4; /* include a 4 instr penalty */
if (total_insns > MAX_INSNS_PER_PATH)
return -ENOMEM;
return ERR_PTR(-EINVAL);
BUG_ON(INT_MAX / fprog->len < sizeof(struct sock_filter));
fp_size = fprog->len * sizeof(struct sock_filter);
/*
* Installing a seccomp filter requires that the task has
@@ -224,14 +359,14 @@ static long seccomp_attach_filter(struct sock_fprog *fprog)
* This avoids scenarios where unprivileged tasks can affect the
* behavior of privileged children.
*/
if (!current->no_new_privs &&
if (!task_no_new_privs(current) &&
security_capable_noaudit(current_cred(), current_user_ns(),
CAP_SYS_ADMIN) != 0)
return -EACCES;
return ERR_PTR(-EACCES);
fp = kzalloc(fp_size, GFP_KERNEL|__GFP_NOWARN);
if (!fp)
return -ENOMEM;
return ERR_PTR(-ENOMEM);
/* Copy the instructions from fprog. */
ret = -EFAULT;
@@ -275,13 +410,7 @@ static long seccomp_attach_filter(struct sock_fprog *fprog)
sk_filter_select_runtime(filter->prog);
/*
* If there is an existing filter, make it the prev and don't drop its
* task reference.
*/
filter->prev = current->seccomp.filter;
current->seccomp.filter = filter;
return 0;
return filter;
free_filter_prog:
kfree(filter->prog);
@@ -289,19 +418,20 @@ free_filter:
kfree(filter);
free_prog:
kfree(fp);
return ret;
return ERR_PTR(ret);
}
/**
* seccomp_attach_user_filter - attaches a user-supplied sock_fprog
* seccomp_prepare_user_filter - prepares a user-supplied sock_fprog
* @user_filter: pointer to the user data containing a sock_fprog.
*
* Returns 0 on success and non-zero otherwise.
*/
static long seccomp_attach_user_filter(char __user *user_filter)
static struct seccomp_filter *
seccomp_prepare_user_filter(const char __user *user_filter)
{
struct sock_fprog fprog;
long ret = -EFAULT;
struct seccomp_filter *filter = ERR_PTR(-EFAULT);
#ifdef CONFIG_COMPAT
if (is_compat_task()) {
@@ -314,9 +444,56 @@ static long seccomp_attach_user_filter(char __user *user_filter)
#endif
if (copy_from_user(&fprog, user_filter, sizeof(fprog)))
goto out;
ret = seccomp_attach_filter(&fprog);
filter = seccomp_prepare_filter(&fprog);
out:
return ret;
return filter;
}
/**
* seccomp_attach_filter: validate and attach filter
* @flags: flags to change filter behavior
* @filter: seccomp filter to add to the current process
*
* Caller must be holding current->sighand->siglock lock.
*
* Returns 0 on success, -ve on error.
*/
static long seccomp_attach_filter(unsigned int flags,
struct seccomp_filter *filter)
{
unsigned long total_insns;
struct seccomp_filter *walker;
BUG_ON(!spin_is_locked(&current->sighand->siglock));
/* Validate resulting filter length. */
total_insns = filter->prog->len;
for (walker = current->seccomp.filter; walker; walker = walker->prev)
total_insns += walker->prog->len + 4; /* 4 instr penalty */
if (total_insns > MAX_INSNS_PER_PATH)
return -ENOMEM;
/* If thread sync has been requested, check that it is possible. */
if (flags & SECCOMP_FILTER_FLAG_TSYNC) {
int ret;
ret = seccomp_can_sync_threads();
if (ret)
return ret;
}
/*
* If there is an existing filter, make it the prev and don't drop its
* task reference.
*/
filter->prev = current->seccomp.filter;
current->seccomp.filter = filter;
/* Now that the new filter is in place, synchronize to all threads. */
if (flags & SECCOMP_FILTER_FLAG_TSYNC)
seccomp_sync_threads();
return 0;
}
/* get_seccomp_filter - increments the reference count of the filter on @tsk */
@@ -329,6 +506,14 @@ void get_seccomp_filter(struct task_struct *tsk)
atomic_inc(&orig->usage);
}
static inline void seccomp_filter_free(struct seccomp_filter *filter)
{
if (filter) {
sk_filter_free(filter->prog);
kfree(filter);
}
}
/* put_seccomp_filter - decrements the ref count of tsk->seccomp.filter */
void put_seccomp_filter(struct task_struct *tsk)
{
@@ -337,8 +522,7 @@ void put_seccomp_filter(struct task_struct *tsk)
while (orig && atomic_dec_and_test(&orig->usage)) {
struct seccomp_filter *freeme = orig;
orig = orig->prev;
sk_filter_free(freeme->prog);
kfree(freeme);
seccomp_filter_free(freeme);
}
}
@@ -382,12 +566,17 @@ static int mode1_syscalls_32[] = {
int __secure_computing(int this_syscall)
{
int mode = current->seccomp.mode;
int exit_sig = 0;
int *syscall;
u32 ret;
switch (mode) {
/*
* Make sure that any changes to mode from another thread have
* been seen after TIF_SECCOMP was seen.
*/
rmb();
switch (current->seccomp.mode) {
case SECCOMP_MODE_STRICT:
syscall = mode1_syscalls;
#ifdef CONFIG_COMPAT
@@ -473,47 +662,152 @@ long prctl_get_seccomp(void)
}
/**
* prctl_set_seccomp: configures current->seccomp.mode
* @seccomp_mode: requested mode to use
* @filter: optional struct sock_fprog for use with SECCOMP_MODE_FILTER
*
* This function may be called repeatedly with a @seccomp_mode of
* SECCOMP_MODE_FILTER to install additional filters. Every filter
* successfully installed will be evaluated (in reverse order) for each system
* call the task makes.
* seccomp_set_mode_strict: internal function for setting strict seccomp
*
* Once current->seccomp.mode is non-zero, it may not be changed.
*
* Returns 0 on success or -EINVAL on failure.
*/
long prctl_set_seccomp(unsigned long seccomp_mode, char __user *filter)
static long seccomp_set_mode_strict(void)
{
const unsigned long seccomp_mode = SECCOMP_MODE_STRICT;
long ret = -EINVAL;
if (current->seccomp.mode &&
current->seccomp.mode != seccomp_mode)
spin_lock_irq(&current->sighand->siglock);
if (!seccomp_may_assign_mode(seccomp_mode))
goto out;
#ifdef TIF_NOTSC
disable_TSC();
#endif
seccomp_assign_mode(current, seccomp_mode);
ret = 0;
out:
spin_unlock_irq(&current->sighand->siglock);
return ret;
}
#ifdef CONFIG_SECCOMP_FILTER
/**
* seccomp_set_mode_filter: internal function for setting seccomp filter
* @flags: flags to change filter behavior
* @filter: struct sock_fprog containing filter
*
* This function may be called repeatedly to install additional filters.
* Every filter successfully installed will be evaluated (in reverse order)
* for each system call the task makes.
*
* Once current->seccomp.mode is non-zero, it may not be changed.
*
* Returns 0 on success or -EINVAL on failure.
*/
static long seccomp_set_mode_filter(unsigned int flags,
const char __user *filter)
{
const unsigned long seccomp_mode = SECCOMP_MODE_FILTER;
struct seccomp_filter *prepared = NULL;
long ret = -EINVAL;
/* Validate flags. */
if (flags & ~SECCOMP_FILTER_FLAG_MASK)
return -EINVAL;
/* Prepare the new filter before holding any locks. */
prepared = seccomp_prepare_user_filter(filter);
if (IS_ERR(prepared))
return PTR_ERR(prepared);
/*
* Make sure we cannot change seccomp or nnp state via TSYNC
* while another thread is in the middle of calling exec.
*/
if (flags & SECCOMP_FILTER_FLAG_TSYNC &&
mutex_lock_killable(&current->signal->cred_guard_mutex))
goto out_free;
spin_lock_irq(&current->sighand->siglock);
if (!seccomp_may_assign_mode(seccomp_mode))
goto out;
ret = seccomp_attach_filter(flags, prepared);
if (ret)
goto out;
/* Do not free the successfully attached filter. */
prepared = NULL;
seccomp_assign_mode(current, seccomp_mode);
out:
spin_unlock_irq(&current->sighand->siglock);
if (flags & SECCOMP_FILTER_FLAG_TSYNC)
mutex_unlock(&current->signal->cred_guard_mutex);
out_free:
seccomp_filter_free(prepared);
return ret;
}
#else
static inline long seccomp_set_mode_filter(unsigned int flags,
const char __user *filter)
{
return -EINVAL;
}
#endif
/* Common entry point for both prctl and syscall. */
static long do_seccomp(unsigned int op, unsigned int flags,
const char __user *uargs)
{
switch (op) {
case SECCOMP_SET_MODE_STRICT:
if (flags != 0 || uargs != NULL)
return -EINVAL;
return seccomp_set_mode_strict();
case SECCOMP_SET_MODE_FILTER:
return seccomp_set_mode_filter(flags, uargs);
default:
return -EINVAL;
}
}
SYSCALL_DEFINE3(seccomp, unsigned int, op, unsigned int, flags,
const char __user *, uargs)
{
return do_seccomp(op, flags, uargs);
}
/**
* prctl_set_seccomp: configures current->seccomp.mode
* @seccomp_mode: requested mode to use
* @filter: optional struct sock_fprog for use with SECCOMP_MODE_FILTER
*
* Returns 0 on success or -EINVAL on failure.
*/
long prctl_set_seccomp(unsigned long seccomp_mode, char __user *filter)
{
unsigned int op;
char __user *uargs;
switch (seccomp_mode) {
case SECCOMP_MODE_STRICT:
ret = 0;
#ifdef TIF_NOTSC
disable_TSC();
#endif
op = SECCOMP_SET_MODE_STRICT;
/*
* Setting strict mode through prctl always ignored filter,
* so make sure it is always NULL here to pass the internal
* check in do_seccomp().
*/
uargs = NULL;
break;
#ifdef CONFIG_SECCOMP_FILTER
case SECCOMP_MODE_FILTER:
ret = seccomp_attach_user_filter(filter);
if (ret)
goto out;
op = SECCOMP_SET_MODE_FILTER;
uargs = filter;
break;
#endif
default:
goto out;
return -EINVAL;
}
current->seccomp.mode = seccomp_mode;
set_thread_flag(TIF_SECCOMP);
out:
return ret;
/* prctl interface doesn't have flags, so they are always zero. */
return do_seccomp(op, 0, uargs);
}

View File

@@ -1990,12 +1990,12 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
if (arg2 != 1 || arg3 || arg4 || arg5)
return -EINVAL;
current->no_new_privs = 1;
task_set_no_new_privs(current);
break;
case PR_GET_NO_NEW_PRIVS:
if (arg2 || arg3 || arg4 || arg5)
return -EINVAL;
return current->no_new_privs ? 1 : 0;
return task_no_new_privs(current) ? 1 : 0;
case PR_GET_THP_DISABLE:
if (arg2 || arg3 || arg4 || arg5)
return -EINVAL;

View File

@@ -213,3 +213,6 @@ cond_syscall(compat_sys_open_by_handle_at);
/* compare kernel pointers */
cond_syscall(sys_kcmp);
/* operate on Secure Computing state */
cond_syscall(sys_seccomp);

View File

@@ -89,6 +89,7 @@ static __init int load_system_certificate_list(void)
pr_err("Problem loading in-kernel X.509 certificate (%ld)\n",
PTR_ERR(key));
} else {
set_bit(KEY_FLAG_BUILTIN, &key_ref_to_ptr(key)->flags);
pr_notice("Loaded X.509 cert '%s'\n",
key_ref_to_ptr(key)->description);
key_ref_put(key);