diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-08-06 11:06:39 -0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-08-06 11:06:39 -0400 |
| commit | bb2cbf5e9367d8598fecd0c48dead69560750223 (patch) | |
| tree | fb2c620451b90f41a31726bdd82077813f941e39 /kernel | |
| parent | e7fda6c4c3c1a7d6996dd75fd84670fa0b5d448f (diff) | |
| parent | 478d085524c57cf4283699f529d5a4c22188ea69 (diff) | |
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
...
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/audit.c | 2 | ||||
| -rw-r--r-- | kernel/capability.c | 4 | ||||
| -rw-r--r-- | kernel/fork.c | 49 | ||||
| -rw-r--r-- | kernel/seccomp.c | 412 | ||||
| -rw-r--r-- | kernel/sys.c | 4 | ||||
| -rw-r--r-- | kernel/sys_ni.c | 3 | ||||
| -rw-r--r-- | kernel/system_keyring.c | 1 |
7 files changed, 412 insertions, 63 deletions
diff --git a/kernel/audit.c b/kernel/audit.c index 3ef2e0e797e8..ba2ff5a5c600 100644 --- a/kernel/audit.c +++ b/kernel/audit.c | |||
| @@ -1677,7 +1677,7 @@ void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap) | |||
| 1677 | audit_log_format(ab, " %s=", prefix); | 1677 | audit_log_format(ab, " %s=", prefix); |
| 1678 | CAP_FOR_EACH_U32(i) { | 1678 | CAP_FOR_EACH_U32(i) { |
| 1679 | audit_log_format(ab, "%08x", | 1679 | audit_log_format(ab, "%08x", |
| 1680 | cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]); | 1680 | cap->cap[CAP_LAST_U32 - i]); |
| 1681 | } | 1681 | } |
| 1682 | } | 1682 | } |
| 1683 | 1683 | ||
diff --git a/kernel/capability.c b/kernel/capability.c index a5cf13c018ce..989f5bfc57dc 100644 --- a/kernel/capability.c +++ b/kernel/capability.c | |||
| @@ -258,6 +258,10 @@ SYSCALL_DEFINE2(capset, cap_user_header_t, header, const cap_user_data_t, data) | |||
| 258 | i++; | 258 | i++; |
| 259 | } | 259 | } |
| 260 | 260 | ||
| 261 | effective.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK; | ||
| 262 | permitted.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK; | ||
| 263 | inheritable.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK; | ||
| 264 | |||
| 261 | new = prepare_creds(); | 265 | new = prepare_creds(); |
| 262 | if (!new) | 266 | if (!new) |
| 263 | return -ENOMEM; | 267 | return -ENOMEM; |
diff --git a/kernel/fork.c b/kernel/fork.c index 5f1bf3bebb4f..fbd3497b221f 100644 --- a/kernel/fork.c +++ b/kernel/fork.c | |||
| @@ -315,6 +315,15 @@ static struct task_struct *dup_task_struct(struct task_struct *orig) | |||
| 315 | goto free_ti; | 315 | goto free_ti; |
| 316 | 316 | ||
| 317 | tsk->stack = ti; | 317 | tsk->stack = ti; |
| 318 | #ifdef CONFIG_SECCOMP | ||
| 319 | /* | ||
| 320 | * We must handle setting up seccomp filters once we're under | ||
| 321 | * the sighand lock in case orig has changed between now and | ||
| 322 | * then. Until then, filter must be NULL to avoid messing up | ||
| 323 | * the usage counts on the error path calling free_task. | ||
| 324 | */ | ||
| 325 | tsk->seccomp.filter = NULL; | ||
| 326 | #endif | ||
| 318 | 327 | ||
| 319 | setup_thread_stack(tsk, orig); | 328 | setup_thread_stack(tsk, orig); |
| 320 | clear_user_return_notifier(tsk); | 329 | clear_user_return_notifier(tsk); |
| @@ -1081,6 +1090,39 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) | |||
| 1081 | return 0; | 1090 | return 0; |
| 1082 | } | 1091 | } |
| 1083 | 1092 | ||
| 1093 | static void copy_seccomp(struct task_struct *p) | ||
| 1094 | { | ||
| 1095 | #ifdef CONFIG_SECCOMP | ||
| 1096 | /* | ||
| 1097 | * Must be called with sighand->lock held, which is common to | ||
| 1098 | * all threads in the group. Holding cred_guard_mutex is not | ||
| 1099 | * needed because this new task is not yet running and cannot | ||
| 1100 | * be racing exec. | ||
| 1101 | */ | ||
| 1102 | BUG_ON(!spin_is_locked(¤t->sighand->siglock)); | ||
| 1103 | |||
| 1104 | /* Ref-count the new filter user, and assign it. */ | ||
| 1105 | get_seccomp_filter(current); | ||
| 1106 | p->seccomp = current->seccomp; | ||
| 1107 | |||
| 1108 | /* | ||
| 1109 | * Explicitly enable no_new_privs here in case it got set | ||
| 1110 | * between the task_struct being duplicated and holding the | ||
| 1111 | * sighand lock. The seccomp state and nnp must be in sync. | ||
| 1112 | */ | ||
| 1113 | if (task_no_new_privs(current)) | ||
| 1114 | task_set_no_new_privs(p); | ||
| 1115 | |||
| 1116 | /* | ||
| 1117 | * If the parent gained a seccomp mode after copying thread | ||
| 1118 | * flags and between before we held the sighand lock, we have | ||
| 1119 | * to manually enable the seccomp thread flag here. | ||
| 1120 | */ | ||
| 1121 | if (p->seccomp.mode != SECCOMP_MODE_DISABLED) | ||
| 1122 | set_tsk_thread_flag(p, TIF_SECCOMP); | ||
| 1123 | #endif | ||
| 1124 | } | ||
| 1125 | |||
| 1084 | SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr) | 1126 | SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr) |
| 1085 | { | 1127 | { |
| 1086 | current->clear_child_tid = tidptr; | 1128 | current->clear_child_tid = tidptr; |
| @@ -1195,7 +1237,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, | |||
| 1195 | goto fork_out; | 1237 | goto fork_out; |
| 1196 | 1238 | ||
| 1197 | ftrace_graph_init_task(p); | 1239 | ftrace_graph_init_task(p); |
| 1198 | get_seccomp_filter(p); | ||
| 1199 | 1240 | ||
| 1200 | rt_mutex_init_task(p); | 1241 | rt_mutex_init_task(p); |
| 1201 | 1242 | ||
| @@ -1435,6 +1476,12 @@ static struct task_struct *copy_process(unsigned long clone_flags, | |||
| 1435 | spin_lock(¤t->sighand->siglock); | 1476 | spin_lock(¤t->sighand->siglock); |
| 1436 | 1477 | ||
| 1437 | /* | 1478 | /* |
| 1479 | * Copy seccomp details explicitly here, in case they were changed | ||
| 1480 | * before holding sighand lock. | ||
| 1481 | */ | ||
| 1482 | copy_seccomp(p); | ||
| 1483 | |||
| 1484 | /* | ||
| 1438 | * Process group and session signals need to be delivered to just the | 1485 | * Process group and session signals need to be delivered to just the |
| 1439 | * parent before the fork or both the parent and the child after the | 1486 | * parent before the fork or both the parent and the child after the |
| 1440 | * fork. Restart if a signal comes in before we add the new process to | 1487 | * fork. Restart if a signal comes in before we add the new process to |
diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 301bbc24739c..74f460179171 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c | |||
| @@ -18,15 +18,17 @@ | |||
| 18 | #include <linux/compat.h> | 18 | #include <linux/compat.h> |
| 19 | #include <linux/sched.h> | 19 | #include <linux/sched.h> |
| 20 | #include <linux/seccomp.h> | 20 | #include <linux/seccomp.h> |
| 21 | #include <linux/slab.h> | ||
| 22 | #include <linux/syscalls.h> | ||
| 21 | 23 | ||
| 22 | /* #define SECCOMP_DEBUG 1 */ | 24 | /* #define SECCOMP_DEBUG 1 */ |
| 23 | 25 | ||
| 24 | #ifdef CONFIG_SECCOMP_FILTER | 26 | #ifdef CONFIG_SECCOMP_FILTER |
| 25 | #include <asm/syscall.h> | 27 | #include <asm/syscall.h> |
| 26 | #include <linux/filter.h> | 28 | #include <linux/filter.h> |
| 29 | #include <linux/pid.h> | ||
| 27 | #include <linux/ptrace.h> | 30 | #include <linux/ptrace.h> |
| 28 | #include <linux/security.h> | 31 | #include <linux/security.h> |
| 29 | #include <linux/slab.h> | ||
| 30 | #include <linux/tracehook.h> | 32 | #include <linux/tracehook.h> |
| 31 | #include <linux/uaccess.h> | 33 | #include <linux/uaccess.h> |
| 32 | 34 | ||
| @@ -172,21 +174,24 @@ static int seccomp_check_filter(struct sock_filter *filter, unsigned int flen) | |||
| 172 | */ | 174 | */ |
| 173 | static u32 seccomp_run_filters(int syscall) | 175 | static u32 seccomp_run_filters(int syscall) |
| 174 | { | 176 | { |
| 175 | struct seccomp_filter *f; | 177 | struct seccomp_filter *f = ACCESS_ONCE(current->seccomp.filter); |
| 176 | struct seccomp_data sd; | 178 | struct seccomp_data sd; |
| 177 | u32 ret = SECCOMP_RET_ALLOW; | 179 | u32 ret = SECCOMP_RET_ALLOW; |
| 178 | 180 | ||
| 179 | /* Ensure unexpected behavior doesn't result in failing open. */ | 181 | /* Ensure unexpected behavior doesn't result in failing open. */ |
| 180 | if (WARN_ON(current->seccomp.filter == NULL)) | 182 | if (unlikely(WARN_ON(f == NULL))) |
| 181 | return SECCOMP_RET_KILL; | 183 | return SECCOMP_RET_KILL; |
| 182 | 184 | ||
| 185 | /* Make sure cross-thread synced filter points somewhere sane. */ | ||
| 186 | smp_read_barrier_depends(); | ||
| 187 | |||
| 183 | populate_seccomp_data(&sd); | 188 | populate_seccomp_data(&sd); |
| 184 | 189 | ||
| 185 | /* | 190 | /* |
| 186 | * All filters in the list are evaluated and the lowest BPF return | 191 | * All filters in the list are evaluated and the lowest BPF return |
| 187 | * value always takes priority (ignoring the DATA). | 192 | * value always takes priority (ignoring the DATA). |
| 188 | */ | 193 | */ |
| 189 | for (f = current->seccomp.filter; f; f = f->prev) { | 194 | for (; f; f = f->prev) { |
| 190 | u32 cur_ret = SK_RUN_FILTER(f->prog, (void *)&sd); | 195 | u32 cur_ret = SK_RUN_FILTER(f->prog, (void *)&sd); |
| 191 | 196 | ||
| 192 | if ((cur_ret & SECCOMP_RET_ACTION) < (ret & SECCOMP_RET_ACTION)) | 197 | if ((cur_ret & SECCOMP_RET_ACTION) < (ret & SECCOMP_RET_ACTION)) |
| @@ -194,29 +199,159 @@ static u32 seccomp_run_filters(int syscall) | |||
| 194 | } | 199 | } |
| 195 | return ret; | 200 | return ret; |
| 196 | } | 201 | } |
| 202 | #endif /* CONFIG_SECCOMP_FILTER */ | ||
| 203 | |||
| 204 | static inline bool seccomp_may_assign_mode(unsigned long seccomp_mode) | ||
| 205 | { | ||
| 206 | BUG_ON(!spin_is_locked(¤t->sighand->siglock)); | ||
| 207 | |||
| 208 | if (current->seccomp.mode && current->seccomp.mode != seccomp_mode) | ||
| 209 | return false; | ||
| 210 | |||
| 211 | return true; | ||
| 212 | } | ||
| 213 | |||
| 214 | static inline void seccomp_assign_mode(struct task_struct *task, | ||
| 215 | unsigned long seccomp_mode) | ||
| 216 | { | ||
| 217 | BUG_ON(!spin_is_locked(&task->sighand->siglock)); | ||
| 218 | |||
| 219 | task->seccomp.mode = seccomp_mode; | ||
| 220 | /* | ||
| 221 | * Make sure TIF_SECCOMP cannot be set before the mode (and | ||
| 222 | * filter) is set. | ||
| 223 | */ | ||
| 224 | smp_mb__before_atomic(); | ||
| 225 | set_tsk_thread_flag(task, TIF_SECCOMP); | ||
| 226 | } | ||
| 227 | |||
| 228 | #ifdef CONFIG_SECCOMP_FILTER | ||
| 229 | /* Returns 1 if the parent is an ancestor of the child. */ | ||
| 230 | static int is_ancestor(struct seccomp_filter *parent, | ||
| 231 | struct seccomp_filter *child) | ||
| 232 | { | ||
| 233 | /* NULL is the root ancestor. */ | ||
| 234 | if (parent == NULL) | ||
| 235 | return 1; | ||
| 236 | for (; child; child = child->prev) | ||
| 237 | if (child == parent) | ||
| 238 | return 1; | ||
| 239 | return 0; | ||
| 240 | } | ||
| 197 | 241 | ||
| 198 | /** | 242 | /** |
| 199 | * seccomp_attach_filter: Attaches a seccomp filter to current. | 243 | * seccomp_can_sync_threads: checks if all threads can be synchronized |
| 244 | * | ||
| 245 | * Expects sighand and cred_guard_mutex locks to be held. | ||
| 246 | * | ||
| 247 | * Returns 0 on success, -ve on error, or the pid of a thread which was | ||
| 248 | * either not in the correct seccomp mode or it did not have an ancestral | ||
| 249 | * seccomp filter. | ||
| 250 | */ | ||
| 251 | static inline pid_t seccomp_can_sync_threads(void) | ||
| 252 | { | ||
| 253 | struct task_struct *thread, *caller; | ||
| 254 | |||
| 255 | BUG_ON(!mutex_is_locked(¤t->signal->cred_guard_mutex)); | ||
| 256 | BUG_ON(!spin_is_locked(¤t->sighand->siglock)); | ||
| 257 | |||
| 258 | /* Validate all threads being eligible for synchronization. */ | ||
| 259 | caller = current; | ||
| 260 | for_each_thread(caller, thread) { | ||
| 261 | pid_t failed; | ||
| 262 | |||
| 263 | /* Skip current, since it is initiating the sync. */ | ||
| 264 | if (thread == caller) | ||
| 265 | continue; | ||
| 266 | |||
| 267 | if (thread->seccomp.mode == SECCOMP_MODE_DISABLED || | ||
| 268 | (thread->seccomp.mode == SECCOMP_MODE_FILTER && | ||
| 269 | is_ancestor(thread->seccomp.filter, | ||
| 270 | caller->seccomp.filter))) | ||
| 271 | continue; | ||
| 272 | |||
| 273 | /* Return the first thread that cannot be synchronized. */ | ||
| 274 | failed = task_pid_vnr(thread); | ||
| 275 | /* If the pid cannot be resolved, then return -ESRCH */ | ||
| 276 | if (unlikely(WARN_ON(failed == 0))) | ||
| 277 | failed = -ESRCH; | ||
| 278 | return failed; | ||
| 279 | } | ||
| 280 | |||
| 281 | return 0; | ||
| 282 | } | ||
| 283 | |||
| 284 | /** | ||
| 285 | * seccomp_sync_threads: sets all threads to use current's filter | ||
| 286 | * | ||
| 287 | * Expects sighand and cred_guard_mutex locks to be held, and for | ||
| 288 | * seccomp_can_sync_threads() to have returned success already | ||
| 289 | * without dropping the locks. | ||
| 290 | * | ||
| 291 | */ | ||
| 292 | static inline void seccomp_sync_threads(void) | ||
| 293 | { | ||
| 294 | struct task_struct *thread, *caller; | ||
| 295 | |||
| 296 | BUG_ON(!mutex_is_locked(¤t->signal->cred_guard_mutex)); | ||
| 297 | BUG_ON(!spin_is_locked(¤t->sighand->siglock)); | ||
| 298 | |||
| 299 | /* Synchronize all threads. */ | ||
| 300 | caller = current; | ||
| 301 | for_each_thread(caller, thread) { | ||
| 302 | /* Skip current, since it needs no changes. */ | ||
| 303 | if (thread == caller) | ||
| 304 | continue; | ||
| 305 | |||
| 306 | /* Get a task reference for the new leaf node. */ | ||
| 307 | get_seccomp_filter(caller); | ||
| 308 | /* | ||
| 309 | * Drop the task reference to the shared ancestor since | ||
| 310 | * current's path will hold a reference. (This also | ||
| 311 | * allows a put before the assignment.) | ||
| 312 | */ | ||
| 313 | put_seccomp_filter(thread); | ||
| 314 | smp_store_release(&thread->seccomp.filter, | ||
| 315 | caller->seccomp.filter); | ||
| 316 | /* | ||
| 317 | * Opt the other thread into seccomp if needed. | ||
| 318 | * As threads are considered to be trust-realm | ||
| 319 | * equivalent (see ptrace_may_access), it is safe to | ||
| 320 | * allow one thread to transition the other. | ||
| 321 | */ | ||
| 322 | if (thread->seccomp.mode == SECCOMP_MODE_DISABLED) { | ||
| 323 | /* | ||
| 324 | * Don't let an unprivileged task work around | ||
| 325 | * the no_new_privs restriction by creating | ||
| 326 | * a thread that sets it up, enters seccomp, | ||
| 327 | * then dies. | ||
| 328 | */ | ||
| 329 | if (task_no_new_privs(caller)) | ||
| 330 | task_set_no_new_privs(thread); | ||
| 331 | |||
| 332 | seccomp_assign_mode(thread, SECCOMP_MODE_FILTER); | ||
| 333 | } | ||
| 334 | } | ||
| 335 | } | ||
| 336 | |||
| 337 | /** | ||
| 338 | * seccomp_prepare_filter: Prepares a seccomp filter for use. | ||
| 200 | * @fprog: BPF program to install | 339 | * @fprog: BPF program to install |
| 201 | * | 340 | * |
| 202 | * Returns 0 on success or an errno on failure. | 341 | * Returns filter on success or an ERR_PTR on failure. |
| 203 | */ | 342 | */ |
| 204 | static long seccomp_attach_filter(struct sock_fprog *fprog) | 343 | static struct seccomp_filter *seccomp_prepare_filter(struct sock_fprog *fprog) |
| 205 | { | 344 | { |
| 206 | struct seccomp_filter *filter; | 345 | struct seccomp_filter *filter; |
| 207 | unsigned long fp_size = fprog->len * sizeof(struct sock_filter); | 346 | unsigned long fp_size; |
| 208 | unsigned long total_insns = fprog->len; | ||
| 209 | struct sock_filter *fp; | 347 | struct sock_filter *fp; |
| 210 | int new_len; | 348 | int new_len; |
| 211 | long ret; | 349 | long ret; |
| 212 | 350 | ||
| 213 | if (fprog->len == 0 || fprog->len > BPF_MAXINSNS) | 351 | if (fprog->len == 0 || fprog->len > BPF_MAXINSNS) |
| 214 | return -EINVAL; | 352 | return ERR_PTR(-EINVAL); |
| 215 | 353 | BUG_ON(INT_MAX / fprog->len < sizeof(struct sock_filter)); | |
| 216 | for (filter = current->seccomp.filter; filter; filter = filter->prev) | 354 | fp_size = fprog->len * sizeof(struct sock_filter); |
| 217 | total_insns += filter->prog->len + 4; /* include a 4 instr penalty */ | ||
| 218 | if (total_insns > MAX_INSNS_PER_PATH) | ||
| 219 | return -ENOMEM; | ||
| 220 | 355 | ||
| 221 | /* | 356 | /* |
| 222 | * Installing a seccomp filter requires that the task has | 357 | * Installing a seccomp filter requires that the task has |
| @@ -224,14 +359,14 @@ static long seccomp_attach_filter(struct sock_fprog *fprog) | |||
| 224 | * This avoids scenarios where unprivileged tasks can affect the | 359 | * This avoids scenarios where unprivileged tasks can affect the |
| 225 | * behavior of privileged children. | 360 | * behavior of privileged children. |
| 226 | */ | 361 | */ |
| 227 | if (!current->no_new_privs && | 362 | if (!task_no_new_privs(current) && |
| 228 | security_capable_noaudit(current_cred(), current_user_ns(), | 363 | security_capable_noaudit(current_cred(), current_user_ns(), |
| 229 | CAP_SYS_ADMIN) != 0) | 364 | CAP_SYS_ADMIN) != 0) |
| 230 | return -EACCES; | 365 | return ERR_PTR(-EACCES); |
| 231 | 366 | ||
| 232 | fp = kzalloc(fp_size, GFP_KERNEL|__GFP_NOWARN); | 367 | fp = kzalloc(fp_size, GFP_KERNEL|__GFP_NOWARN); |
| 233 | if (!fp) | 368 | if (!fp) |
| 234 | return -ENOMEM; | 369 | return ERR_PTR(-ENOMEM); |
| 235 | 370 | ||
| 236 | /* Copy the instructions from fprog. */ | 371 | /* Copy the instructions from fprog. */ |
| 237 | ret = -EFAULT; | 372 | ret = -EFAULT; |
| @@ -275,13 +410,7 @@ static long seccomp_attach_filter(struct sock_fprog *fprog) | |||
| 275 | 410 | ||
| 276 | sk_filter_select_runtime(filter->prog); | 411 | sk_filter_select_runtime(filter->prog); |
| 277 | 412 | ||
| 278 | /* | 413 | return filter; |
| 279 | * If there is an existing filter, make it the prev and don't drop its | ||
| 280 | * task reference. | ||
| 281 | */ | ||
| 282 | filter->prev = current->seccomp.filter; | ||
| 283 | current->seccomp.filter = filter; | ||
| 284 | return 0; | ||
| 285 | 414 | ||
| 286 | free_filter_prog: | 415 | free_filter_prog: |
| 287 | kfree(filter->prog); | 416 | kfree(filter->prog); |
| @@ -289,19 +418,20 @@ free_filter: | |||
| 289 | kfree(filter); | 418 | kfree(filter); |
| 290 | free_prog: | 419 | free_prog: |
| 291 | kfree(fp); | 420 | kfree(fp); |
| 292 | return ret; | 421 | return ERR_PTR(ret); |
| 293 | } | 422 | } |
| 294 | 423 | ||
| 295 | /** | 424 | /** |
| 296 | * seccomp_attach_user_filter - attaches a user-supplied sock_fprog | 425 | * seccomp_prepare_user_filter - prepares a user-supplied sock_fprog |
| 297 | * @user_filter: pointer to the user data containing a sock_fprog. | 426 | * @user_filter: pointer to the user data containing a sock_fprog. |
| 298 | * | 427 | * |
| 299 | * Returns 0 on success and non-zero otherwise. | 428 | * Returns 0 on success and non-zero otherwise. |
| 300 | */ | 429 | */ |
| 301 | static long seccomp_attach_user_filter(char __user *user_filter) | 430 | static struct seccomp_filter * |
| 431 | seccomp_prepare_user_filter(const char __user *user_filter) | ||
| 302 | { | 432 | { |
| 303 | struct sock_fprog fprog; | 433 | struct sock_fprog fprog; |
| 304 | long ret = -EFAULT; | 434 | struct seccomp_filter *filter = ERR_PTR(-EFAULT); |
| 305 | 435 | ||
| 306 | #ifdef CONFIG_COMPAT | 436 | #ifdef CONFIG_COMPAT |
| 307 | if (is_compat_task()) { | 437 | if (is_compat_task()) { |
| @@ -314,9 +444,56 @@ static long seccomp_attach_user_filter(char __user *user_filter) | |||
| 314 | #endif | 444 | #endif |
| 315 | if (copy_from_user(&fprog, user_filter, sizeof(fprog))) | 445 | if (copy_from_user(&fprog, user_filter, sizeof(fprog))) |
| 316 | goto out; | 446 | goto out; |
| 317 | ret = seccomp_attach_filter(&fprog); | 447 | filter = seccomp_prepare_filter(&fprog); |
| 318 | out: | 448 | out: |
| 319 | return ret; | 449 | return filter; |
| 450 | } | ||
| 451 | |||
| 452 | /** | ||
| 453 | * seccomp_attach_filter: validate and attach filter | ||
| 454 | * @flags: flags to change filter behavior | ||
| 455 | * @filter: seccomp filter to add to the current process | ||
| 456 | * | ||
| 457 | * Caller must be holding current->sighand->siglock lock. | ||
| 458 | * | ||
| 459 | * Returns 0 on success, -ve on error. | ||
| 460 | */ | ||
| 461 | static long seccomp_attach_filter(unsigned int flags, | ||
| 462 | struct seccomp_filter *filter) | ||
| 463 | { | ||
| 464 | unsigned long total_insns; | ||
| 465 | struct seccomp_filter *walker; | ||
| 466 | |||
| 467 | BUG_ON(!spin_is_locked(¤t->sighand->siglock)); | ||
| 468 | |||
| 469 | /* Validate resulting filter length. */ | ||
| 470 | total_insns = filter->prog->len; | ||
| 471 | for (walker = current->seccomp.filter; walker; walker = walker->prev) | ||
| 472 | total_insns += walker->prog->len + 4; /* 4 instr penalty */ | ||
| 473 | if (total_insns > MAX_INSNS_PER_PATH) | ||
| 474 | return -ENOMEM; | ||
| 475 | |||
| 476 | /* If thread sync has been requested, check that it is possible. */ | ||
| 477 | if (flags & SECCOMP_FILTER_FLAG_TSYNC) { | ||
| 478 | int ret; | ||
| 479 | |||
| 480 | ret = seccomp_can_sync_threads(); | ||
| 481 | if (ret) | ||
| 482 | return ret; | ||
| 483 | } | ||
| 484 | |||
| 485 | /* | ||
| 486 | * If there is an existing filter, make it the prev and don't drop its | ||
| 487 | * task reference. | ||
| 488 | */ | ||
| 489 | filter->prev = current->seccomp.filter; | ||
| 490 | current->seccomp.filter = filter; | ||
| 491 | |||
| 492 | /* Now that the new filter is in place, synchronize to all threads. */ | ||
| 493 | if (flags & SECCOMP_FILTER_FLAG_TSYNC) | ||
| 494 | seccomp_sync_threads(); | ||
| 495 | |||
| 496 | return 0; | ||
| 320 | } | 497 | } |
| 321 | 498 | ||
| 322 | /* get_seccomp_filter - increments the reference count of the filter on @tsk */ | 499 | /* get_seccomp_filter - increments the reference count of the filter on @tsk */ |
| @@ -329,6 +506,14 @@ void get_seccomp_filter(struct task_struct *tsk) | |||
| 329 | atomic_inc(&orig->usage); | 506 | atomic_inc(&orig->usage); |
| 330 | } | 507 | } |
| 331 | 508 | ||
| 509 | static inline void seccomp_filter_free(struct seccomp_filter *filter) | ||
| 510 | { | ||
| 511 | if (filter) { | ||
| 512 | sk_filter_free(filter->prog); | ||
| 513 | kfree(filter); | ||
| 514 | } | ||
| 515 | } | ||
| 516 | |||
| 332 | /* put_seccomp_filter - decrements the ref count of tsk->seccomp.filter */ | 517 | /* put_seccomp_filter - decrements the ref count of tsk->seccomp.filter */ |
| 333 | void put_seccomp_filter(struct task_struct *tsk) | 518 | void put_seccomp_filter(struct task_struct *tsk) |
| 334 | { | 519 | { |
| @@ -337,8 +522,7 @@ void put_seccomp_filter(struct task_struct *tsk) | |||
| 337 | while (orig && atomic_dec_and_test(&orig->usage)) { | 522 | while (orig && atomic_dec_and_test(&orig->usage)) { |
| 338 | struct seccomp_filter *freeme = orig; | 523 | struct seccomp_filter *freeme = orig; |
| 339 | orig = orig->prev; | 524 | orig = orig->prev; |
| 340 | sk_filter_free(freeme->prog); | 525 | seccomp_filter_free(freeme); |
| 341 | kfree(freeme); | ||
| 342 | } | 526 | } |
| 343 | } | 527 | } |
| 344 | 528 | ||
| @@ -382,12 +566,17 @@ static int mode1_syscalls_32[] = { | |||
| 382 | 566 | ||
| 383 | int __secure_computing(int this_syscall) | 567 | int __secure_computing(int this_syscall) |
| 384 | { | 568 | { |
| 385 | int mode = current->seccomp.mode; | ||
| 386 | int exit_sig = 0; | 569 | int exit_sig = 0; |
| 387 | int *syscall; | 570 | int *syscall; |
| 388 | u32 ret; | 571 | u32 ret; |
| 389 | 572 | ||
| 390 | switch (mode) { | 573 | /* |
| 574 | * Make sure that any changes to mode from another thread have | ||
| 575 | * been seen after TIF_SECCOMP was seen. | ||
| 576 | */ | ||
| 577 | rmb(); | ||
| 578 | |||
| 579 | switch (current->seccomp.mode) { | ||
| 391 | case SECCOMP_MODE_STRICT: | 580 | case SECCOMP_MODE_STRICT: |
| 392 | syscall = mode1_syscalls; | 581 | syscall = mode1_syscalls; |
| 393 | #ifdef CONFIG_COMPAT | 582 | #ifdef CONFIG_COMPAT |
| @@ -473,47 +662,152 @@ long prctl_get_seccomp(void) | |||
| 473 | } | 662 | } |
| 474 | 663 | ||
| 475 | /** | 664 | /** |
| 476 | * prctl_set_seccomp: configures current->seccomp.mode | 665 | * seccomp_set_mode_strict: internal function for setting strict seccomp |
| 477 | * @seccomp_mode: requested mode to use | ||
| 478 | * @filter: optional struct sock_fprog for use with SECCOMP_MODE_FILTER | ||
| 479 | * | 666 | * |
| 480 | * This function may be called repeatedly with a @seccomp_mode of | 667 | * Once current->seccomp.mode is non-zero, it may not be changed. |
| 481 | * SECCOMP_MODE_FILTER to install additional filters. Every filter | 668 | * |
| 482 | * successfully installed will be evaluated (in reverse order) for each system | 669 | * Returns 0 on success or -EINVAL on failure. |
| 483 | * call the task makes. | 670 | */ |
| 671 | static long seccomp_set_mode_strict(void) | ||
| 672 | { | ||
| 673 | const unsigned long seccomp_mode = SECCOMP_MODE_STRICT; | ||
| 674 | long ret = -EINVAL; | ||
| 675 | |||
| 676 | spin_lock_irq(¤t->sighand->siglock); | ||
| 677 | |||
| 678 | if (!seccomp_may_assign_mode(seccomp_mode)) | ||
| 679 | goto out; | ||
| 680 | |||
| 681 | #ifdef TIF_NOTSC | ||
| 682 | disable_TSC(); | ||
| 683 | #endif | ||
| 684 | seccomp_assign_mode(current, seccomp_mode); | ||
| 685 | ret = 0; | ||
| 686 | |||
| 687 | out: | ||
| 688 | spin_unlock_irq(¤t->sighand->siglock); | ||
| 689 | |||
| 690 | return ret; | ||
| 691 | } | ||
| 692 | |||
| 693 | #ifdef CONFIG_SECCOMP_FILTER | ||
| 694 | /** | ||
| 695 | * seccomp_set_mode_filter: internal function for setting seccomp filter | ||
| 696 | * @flags: flags to change filter behavior | ||
| 697 | * @filter: struct sock_fprog containing filter | ||
| 698 | * | ||
| 699 | * This function may be called repeatedly to install additional filters. | ||
| 700 | * Every filter successfully installed will be evaluated (in reverse order) | ||
| 701 | * for each system call the task makes. | ||
| 484 | * | 702 | * |
| 485 | * Once current->seccomp.mode is non-zero, it may not be changed. | 703 | * Once current->seccomp.mode is non-zero, it may not be changed. |
| 486 | * | 704 | * |
| 487 | * Returns 0 on success or -EINVAL on failure. | 705 | * Returns 0 on success or -EINVAL on failure. |
| 488 | */ | 706 | */ |
| 489 | long prctl_set_seccomp(unsigned long seccomp_mode, char __user *filter) | 707 | static long seccomp_set_mode_filter(unsigned int flags, |
| 708 | const char __user *filter) | ||
| 490 | { | 709 | { |
| 710 | const unsigned long seccomp_mode = SECCOMP_MODE_FILTER; | ||
| 711 | struct seccomp_filter *prepared = NULL; | ||
| 491 | long ret = -EINVAL; | 712 | long ret = -EINVAL; |
| 492 | 713 | ||
| 493 | if (current->seccomp.mode && | 714 | /* Validate flags. */ |
| 494 | current->seccomp.mode != seccomp_mode) | 715 | if (flags & ~SECCOMP_FILTER_FLAG_MASK) |
| 716 | return -EINVAL; | ||
| 717 | |||
| 718 | /* Prepare the new filter before holding any locks. */ | ||
| 719 | prepared = seccomp_prepare_user_filter(filter); | ||
| 720 | if (IS_ERR(prepared)) | ||
| 721 | return PTR_ERR(prepared); | ||
| 722 | |||
| 723 | /* | ||
| 724 | * Make sure we cannot change seccomp or nnp state via TSYNC | ||
| 725 | * while another thread is in the middle of calling exec. | ||
| 726 | */ | ||
| 727 | if (flags & SECCOMP_FILTER_FLAG_TSYNC && | ||
| 728 | mutex_lock_killable(¤t->signal->cred_guard_mutex)) | ||
| 729 | goto out_free; | ||
| 730 | |||
| 731 | spin_lock_irq(¤t->sighand->siglock); | ||
| 732 | |||
| 733 | if (!seccomp_may_assign_mode(seccomp_mode)) | ||
| 734 | goto out; | ||
| 735 | |||
| 736 | ret = seccomp_attach_filter(flags, prepared); | ||
| 737 | if (ret) | ||
| 495 | goto out; | 738 | goto out; |
| 739 | /* Do not free the successfully attached filter. */ | ||
| 740 | prepared = NULL; | ||
| 741 | |||
| 742 | seccomp_assign_mode(current, seccomp_mode); | ||
| 743 | out: | ||
| 744 | spin_unlock_irq(¤t->sighand->siglock); | ||
| 745 | if (flags & SECCOMP_FILTER_FLAG_TSYNC) | ||
| 746 | mutex_unlock(¤t->signal->cred_guard_mutex); | ||
| 747 | out_free: | ||
| 748 | seccomp_filter_free(prepared); | ||
| 749 | return ret; | ||
| 750 | } | ||
| 751 | #else | ||
| 752 | static inline long seccomp_set_mode_filter(unsigned int flags, | ||
| 753 | const char __user *filter) | ||
| 754 | { | ||
| 755 | return -EINVAL; | ||
| 756 | } | ||
| 757 | #endif | ||
| 758 | |||
| 759 | /* Common entry point for both prctl and syscall. */ | ||
| 760 | static long do_seccomp(unsigned int op, unsigned int flags, | ||
| 761 | const char __user *uargs) | ||
| 762 | { | ||
| 763 | switch (op) { | ||
| 764 | case SECCOMP_SET_MODE_STRICT: | ||
| 765 | if (flags != 0 || uargs != NULL) | ||
| 766 | return -EINVAL; | ||
| 767 | return seccomp_set_mode_strict(); | ||
| 768 | case SECCOMP_SET_MODE_FILTER: | ||
| 769 | return seccomp_set_mode_filter(flags, uargs); | ||
| 770 | default: | ||
| 771 | return -EINVAL; | ||
| 772 | } | ||
| 773 | } | ||
| 774 | |||
| 775 | SYSCALL_DEFINE3(seccomp, unsigned int, op, unsigned int, flags, | ||
| 776 | const char __user *, uargs) | ||
| 777 | { | ||
| 778 | return do_seccomp(op, flags, uargs); | ||
| 779 | } | ||
| 780 | |||
| 781 | /** | ||
| 782 | * prctl_set_seccomp: configures current->seccomp.mode | ||
| 783 | * @seccomp_mode: requested mode to use | ||
| 784 | * @filter: optional struct sock_fprog for use with SECCOMP_MODE_FILTER | ||
| 785 | * | ||
| 786 | * Returns 0 on success or -EINVAL on failure. | ||
| 787 | */ | ||
| 788 | long prctl_set_seccomp(unsigned long seccomp_mode, char __user *filter) | ||
| 789 | { | ||
| 790 | unsigned int op; | ||
| 791 | char __user *uargs; | ||
| 496 | 792 | ||
| 497 | switch (seccomp_mode) { | 793 | switch (seccomp_mode) { |
| 498 | case SECCOMP_MODE_STRICT: | 794 | case SECCOMP_MODE_STRICT: |
| 499 | ret = 0; | 795 | op = SECCOMP_SET_MODE_STRICT; |
| 500 | #ifdef TIF_NOTSC | 796 | /* |
| 501 | disable_TSC(); | 797 | * Setting strict mode through prctl always ignored filter, |
| 502 | #endif | 798 | * so make sure it is always NULL here to pass the internal |
| 799 | * check in do_seccomp(). | ||
| 800 | */ | ||
| 801 | uargs = NULL; | ||
| 503 | break; | 802 | break; |
| 504 | #ifdef CONFIG_SECCOMP_FILTER | ||
| 505 | case SECCOMP_MODE_FILTER: | 803 | case SECCOMP_MODE_FILTER: |
| 506 | ret = seccomp_attach_user_filter(filter); | 804 | op = SECCOMP_SET_MODE_FILTER; |
| 507 | if (ret) | 805 | uargs = filter; |
| 508 | goto out; | ||
| 509 | break; | 806 | break; |
| 510 | #endif | ||
| 511 | default: | 807 | default: |
| 512 | goto out; | 808 | return -EINVAL; |
| 513 | } | 809 | } |
| 514 | 810 | ||
| 515 | current->seccomp.mode = seccomp_mode; | 811 | /* prctl interface doesn't have flags, so they are always zero. */ |
| 516 | set_thread_flag(TIF_SECCOMP); | 812 | return do_seccomp(op, 0, uargs); |
| 517 | out: | ||
| 518 | return ret; | ||
| 519 | } | 813 | } |
diff --git a/kernel/sys.c b/kernel/sys.c index 66a751ebf9d9..ce8129192a26 100644 --- a/kernel/sys.c +++ b/kernel/sys.c | |||
| @@ -1990,12 +1990,12 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, | |||
| 1990 | if (arg2 != 1 || arg3 || arg4 || arg5) | 1990 | if (arg2 != 1 || arg3 || arg4 || arg5) |
| 1991 | return -EINVAL; | 1991 | return -EINVAL; |
| 1992 | 1992 | ||
| 1993 | current->no_new_privs = 1; | 1993 | task_set_no_new_privs(current); |
| 1994 | break; | 1994 | break; |
| 1995 | case PR_GET_NO_NEW_PRIVS: | 1995 | case PR_GET_NO_NEW_PRIVS: |
| 1996 | if (arg2 || arg3 || arg4 || arg5) | 1996 | if (arg2 || arg3 || arg4 || arg5) |
| 1997 | return -EINVAL; | 1997 | return -EINVAL; |
| 1998 | return current->no_new_privs ? 1 : 0; | 1998 | return task_no_new_privs(current) ? 1 : 0; |
| 1999 | case PR_GET_THP_DISABLE: | 1999 | case PR_GET_THP_DISABLE: |
| 2000 | if (arg2 || arg3 || arg4 || arg5) | 2000 | if (arg2 || arg3 || arg4 || arg5) |
| 2001 | return -EINVAL; | 2001 | return -EINVAL; |
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 36441b51b5df..2904a2105914 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c | |||
| @@ -213,3 +213,6 @@ cond_syscall(compat_sys_open_by_handle_at); | |||
| 213 | 213 | ||
| 214 | /* compare kernel pointers */ | 214 | /* compare kernel pointers */ |
| 215 | cond_syscall(sys_kcmp); | 215 | cond_syscall(sys_kcmp); |
| 216 | |||
| 217 | /* operate on Secure Computing state */ | ||
| 218 | cond_syscall(sys_seccomp); | ||
diff --git a/kernel/system_keyring.c b/kernel/system_keyring.c index 52ebc70263f4..875f64e8935b 100644 --- a/kernel/system_keyring.c +++ b/kernel/system_keyring.c | |||
| @@ -89,6 +89,7 @@ static __init int load_system_certificate_list(void) | |||
| 89 | pr_err("Problem loading in-kernel X.509 certificate (%ld)\n", | 89 | pr_err("Problem loading in-kernel X.509 certificate (%ld)\n", |
| 90 | PTR_ERR(key)); | 90 | PTR_ERR(key)); |
| 91 | } else { | 91 | } else { |
| 92 | set_bit(KEY_FLAG_BUILTIN, &key_ref_to_ptr(key)->flags); | ||
| 92 | pr_notice("Loaded X.509 cert '%s'\n", | 93 | pr_notice("Loaded X.509 cert '%s'\n", |
| 93 | key_ref_to_ptr(key)->description); | 94 | key_ref_to_ptr(key)->description); |
| 94 | key_ref_put(key); | 95 | key_ref_put(key); |
