提交 23c836ce 编写于 作者: L Linus Torvalds

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

Pull keyring/nfs fixes from James Morris:
 "From David Howells:

  The first one fixes the handling of maximum buffer size for key
  descriptions, fixing the size at 4095 + NUL char rather than whatever
  PAGE_SIZE happens to be and permits you to read back the full
  description without it getting clipped because some extra information
  got prepended.

  The second and third fix a bug in NFS idmapper handling whereby a key
  representing a mapping between an id and a name expires and causing
  EKEYEXPIRED to be seen internally in NFS (which prevents the mapping
  from happening) rather than re-looking up the mapping"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  KEYS: request_key() should reget expired keys rather than give EKEYEXPIRED
  KEYS: Simplify KEYRING_SEARCH_{NO,DO}_STATE_CHECK flags
  KEYS: Fix the size of the key description passed to/from userspace
......@@ -117,6 +117,7 @@ struct keyring_search_context {
#define KEYRING_SEARCH_NO_UPDATE_TIME 0x0004 /* Don't update times */
#define KEYRING_SEARCH_NO_CHECK_PERM 0x0008 /* Don't check permissions */
#define KEYRING_SEARCH_DETECT_TOO_DEEP 0x0010 /* Give an error on excessive depth */
#define KEYRING_SEARCH_SKIP_EXPIRED 0x0020 /* Ignore expired keys (intention to replace) */
int (*iterator)(const void *object, void *iterator_data);
......
......@@ -26,6 +26,8 @@
#include <asm/uaccess.h>
#include "internal.h"
#define KEY_MAX_DESC_SIZE 4096
static int key_get_type_from_user(char *type,
const char __user *_type,
unsigned len)
......@@ -78,7 +80,7 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type,
description = NULL;
if (_description) {
description = strndup_user(_description, PAGE_SIZE);
description = strndup_user(_description, KEY_MAX_DESC_SIZE);
if (IS_ERR(description)) {
ret = PTR_ERR(description);
goto error;
......@@ -177,7 +179,7 @@ SYSCALL_DEFINE4(request_key, const char __user *, _type,
goto error;
/* pull the description into kernel space */
description = strndup_user(_description, PAGE_SIZE);
description = strndup_user(_description, KEY_MAX_DESC_SIZE);
if (IS_ERR(description)) {
ret = PTR_ERR(description);
goto error;
......@@ -287,7 +289,7 @@ long keyctl_join_session_keyring(const char __user *_name)
/* fetch the name from userspace */
name = NULL;
if (_name) {
name = strndup_user(_name, PAGE_SIZE);
name = strndup_user(_name, KEY_MAX_DESC_SIZE);
if (IS_ERR(name)) {
ret = PTR_ERR(name);
goto error;
......@@ -562,8 +564,9 @@ long keyctl_describe_key(key_serial_t keyid,
{
struct key *key, *instkey;
key_ref_t key_ref;
char *tmpbuf;
char *infobuf;
long ret;
int desclen, infolen;
key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW);
if (IS_ERR(key_ref)) {
......@@ -586,38 +589,31 @@ long keyctl_describe_key(key_serial_t keyid,
}
okay:
/* calculate how much description we're going to return */
ret = -ENOMEM;
tmpbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!tmpbuf)
goto error2;
key = key_ref_to_ptr(key_ref);
desclen = strlen(key->description);
ret = snprintf(tmpbuf, PAGE_SIZE - 1,
"%s;%d;%d;%08x;%s",
key->type->name,
from_kuid_munged(current_user_ns(), key->uid),
from_kgid_munged(current_user_ns(), key->gid),
key->perm,
key->description ?: "");
/* include a NUL char at the end of the data */
if (ret > PAGE_SIZE - 1)
ret = PAGE_SIZE - 1;
tmpbuf[ret] = 0;
ret++;
/* calculate how much information we're going to return */
ret = -ENOMEM;
infobuf = kasprintf(GFP_KERNEL,
"%s;%d;%d;%08x;",
key->type->name,
from_kuid_munged(current_user_ns(), key->uid),
from_kgid_munged(current_user_ns(), key->gid),
key->perm);
if (!infobuf)
goto error2;
infolen = strlen(infobuf);
ret = infolen + desclen + 1;
/* consider returning the data */
if (buffer && buflen > 0) {
if (buflen > ret)
buflen = ret;
if (copy_to_user(buffer, tmpbuf, buflen) != 0)
if (buffer && buflen >= ret) {
if (copy_to_user(buffer, infobuf, infolen) != 0 ||
copy_to_user(buffer + infolen, key->description,
desclen + 1) != 0)
ret = -EFAULT;
}
kfree(tmpbuf);
kfree(infobuf);
error2:
key_ref_put(key_ref);
error:
......@@ -649,7 +645,7 @@ long keyctl_keyring_search(key_serial_t ringid,
if (ret < 0)
goto error;
description = strndup_user(_description, PAGE_SIZE);
description = strndup_user(_description, KEY_MAX_DESC_SIZE);
if (IS_ERR(description)) {
ret = PTR_ERR(description);
goto error;
......
......@@ -546,7 +546,8 @@ static int keyring_search_iterator(const void *object, void *iterator_data)
}
if (key->expiry && ctx->now.tv_sec >= key->expiry) {
ctx->result = ERR_PTR(-EKEYEXPIRED);
if (!(ctx->flags & KEYRING_SEARCH_SKIP_EXPIRED))
ctx->result = ERR_PTR(-EKEYEXPIRED);
kleave(" = %d [expire]", ctx->skipped_ret);
goto skipped;
}
......@@ -628,6 +629,10 @@ static bool search_nested_keyrings(struct key *keyring,
ctx->index_key.type->name,
ctx->index_key.description);
#define STATE_CHECKS (KEYRING_SEARCH_NO_STATE_CHECK | KEYRING_SEARCH_DO_STATE_CHECK)
BUG_ON((ctx->flags & STATE_CHECKS) == 0 ||
(ctx->flags & STATE_CHECKS) == STATE_CHECKS);
if (ctx->index_key.description)
ctx->index_key.desc_len = strlen(ctx->index_key.description);
......@@ -637,7 +642,6 @@ static bool search_nested_keyrings(struct key *keyring,
if (ctx->match_data.lookup_type == KEYRING_SEARCH_LOOKUP_ITERATE ||
keyring_compare_object(keyring, &ctx->index_key)) {
ctx->skipped_ret = 2;
ctx->flags |= KEYRING_SEARCH_DO_STATE_CHECK;
switch (ctx->iterator(keyring_key_to_ptr(keyring), ctx)) {
case 1:
goto found;
......@@ -649,8 +653,6 @@ static bool search_nested_keyrings(struct key *keyring,
}
ctx->skipped_ret = 0;
if (ctx->flags & KEYRING_SEARCH_NO_STATE_CHECK)
ctx->flags &= ~KEYRING_SEARCH_DO_STATE_CHECK;
/* Start processing a new keyring */
descend_to_keyring:
......
......@@ -516,6 +516,8 @@ struct key *request_key_and_link(struct key_type *type,
.match_data.cmp = key_default_cmp,
.match_data.raw_data = description,
.match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
.flags = (KEYRING_SEARCH_DO_STATE_CHECK |
KEYRING_SEARCH_SKIP_EXPIRED),
};
struct key *key;
key_ref_t key_ref;
......
......@@ -249,6 +249,7 @@ struct key *key_get_instantiation_authkey(key_serial_t target_id)
.match_data.cmp = key_default_cmp,
.match_data.raw_data = description,
.match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
.flags = KEYRING_SEARCH_DO_STATE_CHECK,
};
struct key *authkey;
key_ref_t authkey_ref;
......
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