Merge branch 'fixes-v4.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull security subsystem fixes from James Morris:

 - keys fixes via David Howells:
      "A collection of fixes for Linux keyrings, mostly thanks to Eric
       Biggers:

        - Fix some PKCS#7 verification issues.

        - Fix handling of unsupported crypto in X.509.

        - Fix too-large allocation in big_key"

 - Seccomp updates via Kees Cook:
      "These are fixes for the get_metadata interface that landed during
       -rc1. While the new selftest is strictly not a bug fix, I think
       it's in the same spirit of avoiding bugs"

 - an IMA build fix from Randy Dunlap

* 'fixes-v4.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  integrity/security: fix digsig.c build error with header file
  KEYS: Use individual pages in big_key for crypto buffers
  X.509: fix NULL dereference when restricting key with unsupported_sig
  X.509: fix BUG_ON() when hash algorithm is unsupported
  PKCS#7: fix direct verification of SignerInfo signature
  PKCS#7: fix certificate blacklisting
  PKCS#7: fix certificate chain verification
  seccomp: add a selftest for get_metadata
  ptrace, seccomp: tweak get_metadata behavior slightly
  seccomp, ptrace: switch get_metadata types to arch independent
This commit is contained in:
Linus Torvalds 2018-02-23 15:04:24 -08:00
commit 2eb02aa94f
9 changed files with 179 additions and 41 deletions

View File

@ -106,6 +106,7 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
pr_devel("sinfo %u: Direct signer is key %x\n",
sinfo->index, key_serial(key));
x509 = NULL;
sig = sinfo->sig;
goto matched;
}
if (PTR_ERR(key) != -ENOKEY)

View File

@ -270,7 +270,7 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
sinfo->index);
return 0;
}
ret = public_key_verify_signature(p->pub, p->sig);
ret = public_key_verify_signature(p->pub, x509->sig);
if (ret < 0)
return ret;
x509->signer = p;
@ -366,8 +366,7 @@ static int pkcs7_verify_one(struct pkcs7_message *pkcs7,
*
* (*) -EBADMSG if some part of the message was invalid, or:
*
* (*) 0 if no signature chains were found to be blacklisted or to contain
* unsupported crypto, or:
* (*) 0 if a signature chain passed verification, or:
*
* (*) -EKEYREJECTED if a blacklisted key was encountered, or:
*
@ -423,8 +422,11 @@ int pkcs7_verify(struct pkcs7_message *pkcs7,
for (sinfo = pkcs7->signed_infos; sinfo; sinfo = sinfo->next) {
ret = pkcs7_verify_one(pkcs7, sinfo);
if (sinfo->blacklisted && actual_ret == -ENOPKG)
actual_ret = -EKEYREJECTED;
if (sinfo->blacklisted) {
if (actual_ret == -ENOPKG)
actual_ret = -EKEYREJECTED;
continue;
}
if (ret < 0) {
if (ret == -ENOPKG) {
sinfo->unsupported_crypto = true;

View File

@ -79,9 +79,11 @@ int public_key_verify_signature(const struct public_key *pkey,
BUG_ON(!pkey);
BUG_ON(!sig);
BUG_ON(!sig->digest);
BUG_ON(!sig->s);
if (!sig->digest)
return -ENOPKG;
alg_name = sig->pkey_algo;
if (strcmp(sig->pkey_algo, "rsa") == 0) {
/* The data wangled by the RSA algorithm is typically padded

View File

@ -67,8 +67,9 @@ __setup("ca_keys=", ca_keys_setup);
*
* Returns 0 if the new certificate was accepted, -ENOKEY if we couldn't find a
* matching parent certificate in the trusted list, -EKEYREJECTED if the
* signature check fails or the key is blacklisted and some other error if
* there is a matching certificate but the signature check cannot be performed.
* signature check fails or the key is blacklisted, -ENOPKG if the signature
* uses unsupported crypto, or some other error if there is a matching
* certificate but the signature check cannot be performed.
*/
int restrict_link_by_signature(struct key *dest_keyring,
const struct key_type *type,
@ -88,6 +89,8 @@ int restrict_link_by_signature(struct key *dest_keyring,
return -EOPNOTSUPP;
sig = payload->data[asym_auth];
if (!sig)
return -ENOPKG;
if (!sig->auth_ids[0] && !sig->auth_ids[1])
return -ENOKEY;
@ -139,6 +142,8 @@ static int key_or_keyring_common(struct key *dest_keyring,
return -EOPNOTSUPP;
sig = payload->data[asym_auth];
if (!sig)
return -ENOPKG;
if (!sig->auth_ids[0] && !sig->auth_ids[1])
return -ENOKEY;
@ -222,9 +227,9 @@ static int key_or_keyring_common(struct key *dest_keyring,
*
* Returns 0 if the new certificate was accepted, -ENOKEY if we
* couldn't find a matching parent certificate in the trusted list,
* -EKEYREJECTED if the signature check fails, and some other error if
* there is a matching certificate but the signature check cannot be
* performed.
* -EKEYREJECTED if the signature check fails, -ENOPKG if the signature uses
* unsupported crypto, or some other error if there is a matching certificate
* but the signature check cannot be performed.
*/
int restrict_link_by_key_or_keyring(struct key *dest_keyring,
const struct key_type *type,
@ -249,9 +254,9 @@ int restrict_link_by_key_or_keyring(struct key *dest_keyring,
*
* Returns 0 if the new certificate was accepted, -ENOKEY if we
* couldn't find a matching parent certificate in the trusted list,
* -EKEYREJECTED if the signature check fails, and some other error if
* there is a matching certificate but the signature check cannot be
* performed.
* -EKEYREJECTED if the signature check fails, -ENOPKG if the signature uses
* unsupported crypto, or some other error if there is a matching certificate
* but the signature check cannot be performed.
*/
int restrict_link_by_key_or_keyring_chain(struct key *dest_keyring,
const struct key_type *type,

View File

@ -69,8 +69,8 @@ struct ptrace_peeksiginfo_args {
#define PTRACE_SECCOMP_GET_METADATA 0x420d
struct seccomp_metadata {
unsigned long filter_off; /* Input: which filter */
unsigned int flags; /* Output: filter's flags */
__u64 filter_off; /* Input: which filter */
__u64 flags; /* Output: filter's flags */
};
/* Read signals from a shared (process wide) queue */

View File

@ -1076,14 +1076,16 @@ long seccomp_get_metadata(struct task_struct *task,
size = min_t(unsigned long, size, sizeof(kmd));
if (copy_from_user(&kmd, data, size))
if (size < sizeof(kmd.filter_off))
return -EINVAL;
if (copy_from_user(&kmd.filter_off, data, sizeof(kmd.filter_off)))
return -EFAULT;
filter = get_nth_filter(task, kmd.filter_off);
if (IS_ERR(filter))
return PTR_ERR(filter);
memset(&kmd, 0, sizeof(kmd));
if (filter->log)
kmd.flags |= SECCOMP_FILTER_FLAG_LOG;

View File

@ -18,6 +18,7 @@
#include <linux/cred.h>
#include <linux/key-type.h>
#include <linux/digsig.h>
#include <linux/vmalloc.h>
#include <crypto/public_key.h>
#include <keys/system_keyring.h>

View File

@ -22,6 +22,13 @@
#include <keys/big_key-type.h>
#include <crypto/aead.h>
struct big_key_buf {
unsigned int nr_pages;
void *virt;
struct scatterlist *sg;
struct page *pages[];
};
/*
* Layout of key payload words.
*/
@ -91,10 +98,9 @@ static DEFINE_MUTEX(big_key_aead_lock);
/*
* Encrypt/decrypt big_key data
*/
static int big_key_crypt(enum big_key_op op, u8 *data, size_t datalen, u8 *key)
static int big_key_crypt(enum big_key_op op, struct big_key_buf *buf, size_t datalen, u8 *key)
{
int ret;
struct scatterlist sgio;
struct aead_request *aead_req;
/* We always use a zero nonce. The reason we can get away with this is
* because we're using a different randomly generated key for every
@ -109,8 +115,7 @@ static int big_key_crypt(enum big_key_op op, u8 *data, size_t datalen, u8 *key)
return -ENOMEM;
memset(zero_nonce, 0, sizeof(zero_nonce));
sg_init_one(&sgio, data, datalen + (op == BIG_KEY_ENC ? ENC_AUTHTAG_SIZE : 0));
aead_request_set_crypt(aead_req, &sgio, &sgio, datalen, zero_nonce);
aead_request_set_crypt(aead_req, buf->sg, buf->sg, datalen, zero_nonce);
aead_request_set_callback(aead_req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
aead_request_set_ad(aead_req, 0);
@ -129,22 +134,82 @@ error:
return ret;
}
/*
* Free up the buffer.
*/
static void big_key_free_buffer(struct big_key_buf *buf)
{
unsigned int i;
if (buf->virt) {
memset(buf->virt, 0, buf->nr_pages * PAGE_SIZE);
vunmap(buf->virt);
}
for (i = 0; i < buf->nr_pages; i++)
if (buf->pages[i])
__free_page(buf->pages[i]);
kfree(buf);
}
/*
* Allocate a buffer consisting of a set of pages with a virtual mapping
* applied over them.
*/
static void *big_key_alloc_buffer(size_t len)
{
struct big_key_buf *buf;
unsigned int npg = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
unsigned int i, l;
buf = kzalloc(sizeof(struct big_key_buf) +
sizeof(struct page) * npg +
sizeof(struct scatterlist) * npg,
GFP_KERNEL);
if (!buf)
return NULL;
buf->nr_pages = npg;
buf->sg = (void *)(buf->pages + npg);
sg_init_table(buf->sg, npg);
for (i = 0; i < buf->nr_pages; i++) {
buf->pages[i] = alloc_page(GFP_KERNEL);
if (!buf->pages[i])
goto nomem;
l = min_t(size_t, len, PAGE_SIZE);
sg_set_page(&buf->sg[i], buf->pages[i], l, 0);
len -= l;
}
buf->virt = vmap(buf->pages, buf->nr_pages, VM_MAP, PAGE_KERNEL);
if (!buf->virt)
goto nomem;
return buf;
nomem:
big_key_free_buffer(buf);
return NULL;
}
/*
* Preparse a big key
*/
int big_key_preparse(struct key_preparsed_payload *prep)
{
struct big_key_buf *buf;
struct path *path = (struct path *)&prep->payload.data[big_key_path];
struct file *file;
u8 *enckey;
u8 *data = NULL;
ssize_t written;
size_t datalen = prep->datalen;
size_t datalen = prep->datalen, enclen = datalen + ENC_AUTHTAG_SIZE;
int ret;
ret = -EINVAL;
if (datalen <= 0 || datalen > 1024 * 1024 || !prep->data)
goto error;
return -EINVAL;
/* Set an arbitrary quota */
prep->quotalen = 16;
@ -157,13 +222,12 @@ int big_key_preparse(struct key_preparsed_payload *prep)
*
* File content is stored encrypted with randomly generated key.
*/
size_t enclen = datalen + ENC_AUTHTAG_SIZE;
loff_t pos = 0;
data = kmalloc(enclen, GFP_KERNEL);
if (!data)
buf = big_key_alloc_buffer(enclen);
if (!buf)
return -ENOMEM;
memcpy(data, prep->data, datalen);
memcpy(buf->virt, prep->data, datalen);
/* generate random key */
enckey = kmalloc(ENC_KEY_SIZE, GFP_KERNEL);
@ -176,7 +240,7 @@ int big_key_preparse(struct key_preparsed_payload *prep)
goto err_enckey;
/* encrypt aligned data */
ret = big_key_crypt(BIG_KEY_ENC, data, datalen, enckey);
ret = big_key_crypt(BIG_KEY_ENC, buf, datalen, enckey);
if (ret)
goto err_enckey;
@ -187,7 +251,7 @@ int big_key_preparse(struct key_preparsed_payload *prep)
goto err_enckey;
}
written = kernel_write(file, data, enclen, &pos);
written = kernel_write(file, buf->virt, enclen, &pos);
if (written != enclen) {
ret = written;
if (written >= 0)
@ -202,7 +266,7 @@ int big_key_preparse(struct key_preparsed_payload *prep)
*path = file->f_path;
path_get(path);
fput(file);
kzfree(data);
big_key_free_buffer(buf);
} else {
/* Just store the data in a buffer */
void *data = kmalloc(datalen, GFP_KERNEL);
@ -220,7 +284,7 @@ err_fput:
err_enckey:
kzfree(enckey);
error:
kzfree(data);
big_key_free_buffer(buf);
return ret;
}
@ -298,15 +362,15 @@ long big_key_read(const struct key *key, char __user *buffer, size_t buflen)
return datalen;
if (datalen > BIG_KEY_FILE_THRESHOLD) {
struct big_key_buf *buf;
struct path *path = (struct path *)&key->payload.data[big_key_path];
struct file *file;
u8 *data;
u8 *enckey = (u8 *)key->payload.data[big_key_data];
size_t enclen = datalen + ENC_AUTHTAG_SIZE;
loff_t pos = 0;
data = kmalloc(enclen, GFP_KERNEL);
if (!data)
buf = big_key_alloc_buffer(enclen);
if (!buf)
return -ENOMEM;
file = dentry_open(path, O_RDONLY, current_cred());
@ -316,26 +380,26 @@ long big_key_read(const struct key *key, char __user *buffer, size_t buflen)
}
/* read file to kernel and decrypt */
ret = kernel_read(file, data, enclen, &pos);
ret = kernel_read(file, buf->virt, enclen, &pos);
if (ret >= 0 && ret != enclen) {
ret = -EIO;
goto err_fput;
}
ret = big_key_crypt(BIG_KEY_DEC, data, enclen, enckey);
ret = big_key_crypt(BIG_KEY_DEC, buf, enclen, enckey);
if (ret)
goto err_fput;
ret = datalen;
/* copy decrypted data to user */
if (copy_to_user(buffer, data, datalen) != 0)
if (copy_to_user(buffer, buf->virt, datalen) != 0)
ret = -EFAULT;
err_fput:
fput(file);
error:
kzfree(data);
big_key_free_buffer(buf);
} else {
ret = datalen;
if (copy_to_user(buffer, key->payload.data[big_key_data],

View File

@ -141,6 +141,15 @@ struct seccomp_data {
#define SECCOMP_FILTER_FLAG_LOG 2
#endif
#ifndef PTRACE_SECCOMP_GET_METADATA
#define PTRACE_SECCOMP_GET_METADATA 0x420d
struct seccomp_metadata {
__u64 filter_off; /* Input: which filter */
__u64 flags; /* Output: filter's flags */
};
#endif
#ifndef seccomp
int seccomp(unsigned int op, unsigned int flags, void *args)
{
@ -2845,6 +2854,58 @@ TEST(get_action_avail)
EXPECT_EQ(errno, EOPNOTSUPP);
}
TEST(get_metadata)
{
pid_t pid;
int pipefd[2];
char buf;
struct seccomp_metadata md;
ASSERT_EQ(0, pipe(pipefd));
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0) {
struct sock_filter filter[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
/* one with log, one without */
ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER,
SECCOMP_FILTER_FLAG_LOG, &prog));
ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog));
ASSERT_EQ(0, close(pipefd[0]));
ASSERT_EQ(1, write(pipefd[1], "1", 1));
ASSERT_EQ(0, close(pipefd[1]));
while (1)
sleep(100);
}
ASSERT_EQ(0, close(pipefd[1]));
ASSERT_EQ(1, read(pipefd[0], &buf, 1));
ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid));
ASSERT_EQ(pid, waitpid(pid, NULL, 0));
md.filter_off = 0;
ASSERT_EQ(sizeof(md), ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md));
EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG);
EXPECT_EQ(md.filter_off, 0);
md.filter_off = 1;
ASSERT_EQ(sizeof(md), ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md));
EXPECT_EQ(md.flags, 0);
EXPECT_EQ(md.filter_off, 1);
ASSERT_EQ(0, kill(pid, SIGKILL));
}
/*
* TODO:
* - add microbenchmarks