mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 18:14:07 +08:00
028db3e290
This reverts merge0f75ef6a9c
(and thus effectively commits7a1ade8475
("keys: Provide KEYCTL_GRANT_PERMISSION")2e12256b9a
("keys: Replace uid/gid/perm permissions checking with an ACL") that the merge brought in). It turns out that it breaks booting with an encrypted volume, and Eric biggers reports that it also breaks the fscrypt tests [1] and loading of in-kernel X.509 certificates [2]. The root cause of all the breakage is likely the same, but David Howells is off email so rather than try to work it out it's getting reverted in order to not impact the rest of the merge window. [1] https://lore.kernel.org/lkml/20190710011559.GA7973@sol.localdomain/ [2] https://lore.kernel.org/lkml/20190710013225.GB7973@sol.localdomain/ Link: https://lore.kernel.org/lkml/CAHk-=wjxoeMJfeBahnWH=9zShKp2bsVy527vo3_y8HfOdhwAAw@mail.gmail.com/ Reported-by: Eric Biggers <ebiggers@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
171 lines
3.8 KiB
C
171 lines
3.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/* System hash blacklist.
|
|
*
|
|
* Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*/
|
|
|
|
#define pr_fmt(fmt) "blacklist: "fmt
|
|
#include <linux/module.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/key.h>
|
|
#include <linux/key-type.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/ctype.h>
|
|
#include <linux/err.h>
|
|
#include <linux/seq_file.h>
|
|
#include <keys/system_keyring.h>
|
|
#include "blacklist.h"
|
|
|
|
static struct key *blacklist_keyring;
|
|
|
|
/*
|
|
* The description must be a type prefix, a colon and then an even number of
|
|
* hex digits. The hash is kept in the description.
|
|
*/
|
|
static int blacklist_vet_description(const char *desc)
|
|
{
|
|
int n = 0;
|
|
|
|
if (*desc == ':')
|
|
return -EINVAL;
|
|
for (; *desc; desc++)
|
|
if (*desc == ':')
|
|
goto found_colon;
|
|
return -EINVAL;
|
|
|
|
found_colon:
|
|
desc++;
|
|
for (; *desc; desc++) {
|
|
if (!isxdigit(*desc))
|
|
return -EINVAL;
|
|
n++;
|
|
}
|
|
|
|
if (n == 0 || n & 1)
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* The hash to be blacklisted is expected to be in the description. There will
|
|
* be no payload.
|
|
*/
|
|
static int blacklist_preparse(struct key_preparsed_payload *prep)
|
|
{
|
|
if (prep->datalen > 0)
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
static void blacklist_free_preparse(struct key_preparsed_payload *prep)
|
|
{
|
|
}
|
|
|
|
static void blacklist_describe(const struct key *key, struct seq_file *m)
|
|
{
|
|
seq_puts(m, key->description);
|
|
}
|
|
|
|
static struct key_type key_type_blacklist = {
|
|
.name = "blacklist",
|
|
.vet_description = blacklist_vet_description,
|
|
.preparse = blacklist_preparse,
|
|
.free_preparse = blacklist_free_preparse,
|
|
.instantiate = generic_key_instantiate,
|
|
.describe = blacklist_describe,
|
|
};
|
|
|
|
/**
|
|
* mark_hash_blacklisted - Add a hash to the system blacklist
|
|
* @hash - The hash as a hex string with a type prefix (eg. "tbs:23aa429783")
|
|
*/
|
|
int mark_hash_blacklisted(const char *hash)
|
|
{
|
|
key_ref_t key;
|
|
|
|
key = key_create_or_update(make_key_ref(blacklist_keyring, true),
|
|
"blacklist",
|
|
hash,
|
|
NULL,
|
|
0,
|
|
((KEY_POS_ALL & ~KEY_POS_SETATTR) |
|
|
KEY_USR_VIEW),
|
|
KEY_ALLOC_NOT_IN_QUOTA |
|
|
KEY_ALLOC_BUILT_IN);
|
|
if (IS_ERR(key)) {
|
|
pr_err("Problem blacklisting hash (%ld)\n", PTR_ERR(key));
|
|
return PTR_ERR(key);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* is_hash_blacklisted - Determine if a hash is blacklisted
|
|
* @hash: The hash to be checked as a binary blob
|
|
* @hash_len: The length of the binary hash
|
|
* @type: Type of hash
|
|
*/
|
|
int is_hash_blacklisted(const u8 *hash, size_t hash_len, const char *type)
|
|
{
|
|
key_ref_t kref;
|
|
size_t type_len = strlen(type);
|
|
char *buffer, *p;
|
|
int ret = 0;
|
|
|
|
buffer = kmalloc(type_len + 1 + hash_len * 2 + 1, GFP_KERNEL);
|
|
if (!buffer)
|
|
return -ENOMEM;
|
|
p = memcpy(buffer, type, type_len);
|
|
p += type_len;
|
|
*p++ = ':';
|
|
bin2hex(p, hash, hash_len);
|
|
p += hash_len * 2;
|
|
*p = 0;
|
|
|
|
kref = keyring_search(make_key_ref(blacklist_keyring, true),
|
|
&key_type_blacklist, buffer, false);
|
|
if (!IS_ERR(kref)) {
|
|
key_ref_put(kref);
|
|
ret = -EKEYREJECTED;
|
|
}
|
|
|
|
kfree(buffer);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(is_hash_blacklisted);
|
|
|
|
/*
|
|
* Initialise the blacklist
|
|
*/
|
|
static int __init blacklist_init(void)
|
|
{
|
|
const char *const *bl;
|
|
|
|
if (register_key_type(&key_type_blacklist) < 0)
|
|
panic("Can't allocate system blacklist key type\n");
|
|
|
|
blacklist_keyring =
|
|
keyring_alloc(".blacklist",
|
|
KUIDT_INIT(0), KGIDT_INIT(0),
|
|
current_cred(),
|
|
(KEY_POS_ALL & ~KEY_POS_SETATTR) |
|
|
KEY_USR_VIEW | KEY_USR_READ |
|
|
KEY_USR_SEARCH,
|
|
KEY_ALLOC_NOT_IN_QUOTA |
|
|
KEY_FLAG_KEEP,
|
|
NULL, NULL);
|
|
if (IS_ERR(blacklist_keyring))
|
|
panic("Can't allocate system blacklist keyring\n");
|
|
|
|
for (bl = blacklist_hashes; *bl; bl++)
|
|
if (mark_hash_blacklisted(*bl) < 0)
|
|
pr_err("- blacklisting failed\n");
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Must be initialised before we try and load the keys into the keyring.
|
|
*/
|
|
device_initcall(blacklist_init);
|