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-rw-r--r--security/keys/keyctl.c56
1 files changed, 26 insertions, 30 deletions
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;
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