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authorLinus Torvalds <torvalds@linux-foundation.org>2014-12-03 10:56:12 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-03 10:56:12 -0800
commit23c836ce5c1e1e0bb942f58a3cbc2f7fc05a08b5 (patch)
tree818d1be11860a8fb43dee99a00de68817d0d11db
parent1dd909affbc45412270fd196d1181404d2e416b1 (diff)
parent188324808572faf096a5fd8c1986874bc904dafe (diff)
downloadlinux-linaro-stable-23c836ce5c1e1e0bb942f58a3cbc2f7fc05a08b5.tar.gz
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
-rw-r--r--security/keys/internal.h1
-rw-r--r--security/keys/keyctl.c56
-rw-r--r--security/keys/keyring.c10
-rw-r--r--security/keys/request_key.c2
-rw-r--r--security/keys/request_key_auth.c1
5 files changed, 36 insertions, 34 deletions
diff --git a/security/keys/internal.h b/security/keys/internal.h
index b8960c4..200e378 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -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);
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index eff88a5..4743d71 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -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;
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 8177010..e72548b 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -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:
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index bb4337c..0c7aea4 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -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;
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index 6639e2c..5d672f7 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -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;