#include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * We don't expose the real in-memory order of objects for security reasons. * But still the comparison results should be suitable for sorting. So we * obfuscate kernel pointers values and compare the production instead. * * The obfuscation is done in two steps. First we xor the kernel pointer with * a random value, which puts pointer into a new position in a reordered space. * Secondly we multiply the xor production with a large odd random number to * permute its bits even more (the odd multiplier guarantees that the product * is unique ever after the high bits are truncated, since any odd number is * relative prime to 2^n). * * Note also that the obfuscation itself is invisible to userspace and if needed * it can be changed to an alternate scheme. */ static unsigned long cookies[KCMP_TYPES][2] __read_mostly; static long kptr_obfuscate(long v, int type) { return (v ^ cookies[type][0]) * cookies[type][1]; } /* * 0 - equal, i.e. v1 = v2 * 1 - less than, i.e. v1 < v2 * 2 - greater than, i.e. v1 > v2 * 3 - not equal but ordering unavailable (reserved for future) */ static int kcmp_ptr(void *v1, void *v2, enum kcmp_type type) { long t1, t2; t1 = kptr_obfuscate((long)v1, type); t2 = kptr_obfuscate((long)v2, type); return (t1 < t2) | ((t1 > t2) << 1); } /* The caller must have pinned the task */ static struct file * get_file_raw_ptr(struct task_struct *task, unsigned int idx) { struct file *file = NULL; task_lock(task); rcu_read_lock(); if (task->files) file = fcheck_files(task->files, idx); rcu_read_unlock(); task_unlock(task); return file; } static void kcmp_unlock(struct mutex *m1, struct mutex *m2) { if (likely(m2 != m1)) mutex_unlock(m2); mutex_unlock(m1); } static int kcmp_lock(struct mutex *m1, struct mutex *m2) { int err; if (m2 > m1) swap(m1, m2); err = mutex_lock_killable(m1); if (!err && likely(m1 != m2)) { err = mutex_lock_killable_nested(m2, SINGLE_DEPTH_NESTING); if (err) mutex_unlock(m1); } return err; } SYSCALL_DEFINE5(kcmp, pid_t, pid1, pid_t, pid2, int, type, unsigned long, idx1, unsigned long, idx2) { struct task_struct *task1, *task2; int ret; rcu_read_lock(); /* * Tasks are looked up in caller's PID namespace only. */ task1 = find_task_by_vpid(pid1); task2 = find_task_by_vpid(pid2); if (!task1 || !task2) goto err_no_task; get_task_struct(task1); get_task_struct(task2); rcu_read_unlock(); /* * One should have enough rights to inspect task details. */ ret = kcmp_lock(&task1->signal->cred_guard_mutex, &task2->signal->cred_guard_mutex); if (ret) goto err; if (!ptrace_may_access(task1, PTRACE_MODE_READ_REALCREDS) || !ptrace_may_access(task2, PTRACE_MODE_READ_REALCREDS)) { ret = -EPERM; goto err_unlock; } switch (type) { case KCMP_FILE: { struct file *filp1, *filp2; filp1 = get_file_raw_ptr(task1, idx1); filp2 = get_file_raw_ptr(task2, idx2); if (filp1 && filp2) ret = kcmp_ptr(filp1, filp2, KCMP_FILE); else ret = -EBADF; break; } case KCMP_VM: ret = kcmp_ptr(task1->mm, task2->mm, KCMP_VM); break; case KCMP_FILES: ret = kcmp_ptr(task1->files, task2->files, KCMP_FILES); break; case KCMP_FS: ret = kcmp_ptr(task1->fs, task2->fs, KCMP_FS); break; case KCMP_SIGHAND: ret = kcmp_ptr(task1->sighand, task2->sighand, KCMP_SIGHAND); break; case KCMP_IO: ret = kcmp_ptr(task1->io_context, task2->io_context, KCMP_IO); break; case KCMP_SYSVSEM: #ifdef CONFIG_SYSVIPC ret = kcmp_ptr(task1->sysvsem.undo_list, task2->sysvsem.undo_list, KCMP_SYSVSEM); #else ret = -EOPNOTSUPP; #endif break; default: ret = -EINVAL; break; } err_unlock: kcmp_unlock(&task1->signal->cred_guard_mutex, &task2->signal->cred_guard_mutex); err: put_task_struct(task1); put_task_struct(task2); return ret; err_no_task: rcu_read_unlock(); return -ESRCH; } static __init int kcmp_cookies_init(void) { int i; get_random_bytes(cookies, sizeof(cookies)); for (i = 0; i < KCMP_TYPES; i++) cookies[i][1] |= (~(~0UL >> 1) | 1); return 0; } arch_initcall(kcmp_cookies_init); value='0' selected='selected'>unified
authorArd Biesheuvel <ard.biesheuvel@linaro.org>2017-01-17 13:46:29 +0000
committerHerbert Xu <herbert@gondor.apana.org.au>2017-01-23 22:41:33 +0800
commit11e3b725cfc282efe9d4a354153e99d86a16af08 (patch)
tree8b5b9e0e1bcae1ab98ee652ffb7b13b05c209bd6 /include/trace
parentd6040764adcb5cb6de1489422411d701c158bb69 (diff)
crypto: arm64/aes-blk - honour iv_out requirement in CBC and CTR modes
Update the ARMv8 Crypto Extensions and the plain NEON AES implementations in CBC and CTR modes to return the next IV back to the skcipher API client. This is necessary for chaining to work correctly. Note that for CTR, this is only done if the request is a round multiple of the block size, since otherwise, chaining is impossible anyway. Cc: <stable@vger.kernel.org> # v3.16+ Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'include/trace')