[PATCH] strndup_user: convert keyctl
Copies user-space string with strndup_user() and moves the type string duplication code to a function (thus fixing a wrong check on the length of the type.) Signed-off-by: Davi Arnaut <davi.arnaut@gmail.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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24277dda3a
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0cb409d98e
1 changed files with 50 additions and 105 deletions
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@ -17,10 +17,33 @@
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#include <linux/keyctl.h>
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#include <linux/fs.h>
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#include <linux/capability.h>
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#include <linux/string.h>
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#include <linux/err.h>
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#include <asm/uaccess.h>
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#include "internal.h"
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static int key_get_type_from_user(char *type,
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const char __user *_type,
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unsigned len)
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{
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int ret;
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ret = strncpy_from_user(type, _type, len);
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if (ret < 0)
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return -EFAULT;
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if (ret == 0 || ret >= len)
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return -EINVAL;
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if (type[0] == '.')
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return -EPERM;
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type[len - 1] = '\0';
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return 0;
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}
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/*****************************************************************************/
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/*
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* extract the description of a new key from userspace and either add it as a
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@ -38,40 +61,22 @@ asmlinkage long sys_add_key(const char __user *_type,
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key_ref_t keyring_ref, key_ref;
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char type[32], *description;
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void *payload;
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long dlen, ret;
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long ret;
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ret = -EINVAL;
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if (plen > 32767)
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goto error;
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/* draw all the data into kernel space */
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ret = strncpy_from_user(type, _type, sizeof(type) - 1);
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ret = key_get_type_from_user(type, _type, sizeof(type));
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if (ret < 0)
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goto error;
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type[31] = '\0';
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ret = -EPERM;
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if (type[0] == '.')
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description = strndup_user(_description, PAGE_SIZE);
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if (IS_ERR(description)) {
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ret = PTR_ERR(description);
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goto error;
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ret = -EFAULT;
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dlen = strnlen_user(_description, PAGE_SIZE - 1);
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if (dlen <= 0)
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goto error;
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ret = -EINVAL;
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if (dlen > PAGE_SIZE - 1)
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goto error;
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ret = -ENOMEM;
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description = kmalloc(dlen + 1, GFP_KERNEL);
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if (!description)
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goto error;
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description[dlen] = '\0';
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ret = -EFAULT;
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if (copy_from_user(description, _description, dlen) != 0)
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goto error2;
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}
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/* pull the payload in if one was supplied */
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payload = NULL;
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@ -136,59 +141,28 @@ asmlinkage long sys_request_key(const char __user *_type,
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struct key *key;
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key_ref_t dest_ref;
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char type[32], *description, *callout_info;
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long dlen, ret;
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long ret;
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/* pull the type into kernel space */
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ret = strncpy_from_user(type, _type, sizeof(type) - 1);
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ret = key_get_type_from_user(type, _type, sizeof(type));
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if (ret < 0)
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goto error;
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type[31] = '\0';
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ret = -EPERM;
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if (type[0] == '.')
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goto error;
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/* pull the description into kernel space */
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ret = -EFAULT;
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dlen = strnlen_user(_description, PAGE_SIZE - 1);
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if (dlen <= 0)
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description = strndup_user(_description, PAGE_SIZE);
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if (IS_ERR(description)) {
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ret = PTR_ERR(description);
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goto error;
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ret = -EINVAL;
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if (dlen > PAGE_SIZE - 1)
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goto error;
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ret = -ENOMEM;
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description = kmalloc(dlen + 1, GFP_KERNEL);
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if (!description)
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goto error;
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description[dlen] = '\0';
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ret = -EFAULT;
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if (copy_from_user(description, _description, dlen) != 0)
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goto error2;
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}
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/* pull the callout info into kernel space */
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callout_info = NULL;
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if (_callout_info) {
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ret = -EFAULT;
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dlen = strnlen_user(_callout_info, PAGE_SIZE - 1);
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if (dlen <= 0)
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callout_info = strndup_user(_callout_info, PAGE_SIZE);
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if (IS_ERR(callout_info)) {
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ret = PTR_ERR(callout_info);
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goto error2;
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ret = -EINVAL;
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if (dlen > PAGE_SIZE - 1)
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goto error2;
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ret = -ENOMEM;
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callout_info = kmalloc(dlen + 1, GFP_KERNEL);
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if (!callout_info)
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goto error2;
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callout_info[dlen] = '\0';
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ret = -EFAULT;
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if (copy_from_user(callout_info, _callout_info, dlen) != 0)
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goto error3;
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}
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}
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/* get the destination keyring if specified */
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@ -264,36 +238,21 @@ long keyctl_get_keyring_ID(key_serial_t id, int create)
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long keyctl_join_session_keyring(const char __user *_name)
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{
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char *name;
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long nlen, ret;
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long ret;
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/* fetch the name from userspace */
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name = NULL;
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if (_name) {
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ret = -EFAULT;
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nlen = strnlen_user(_name, PAGE_SIZE - 1);
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if (nlen <= 0)
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name = strndup_user(_name, PAGE_SIZE);
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if (IS_ERR(name)) {
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ret = PTR_ERR(name);
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goto error;
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ret = -EINVAL;
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if (nlen > PAGE_SIZE - 1)
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goto error;
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ret = -ENOMEM;
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name = kmalloc(nlen + 1, GFP_KERNEL);
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if (!name)
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goto error;
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name[nlen] = '\0';
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ret = -EFAULT;
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if (copy_from_user(name, _name, nlen) != 0)
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goto error2;
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}
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}
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/* join the session */
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ret = join_session_keyring(name);
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error2:
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kfree(name);
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error:
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return ret;
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@ -566,32 +525,18 @@ long keyctl_keyring_search(key_serial_t ringid,
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struct key_type *ktype;
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key_ref_t keyring_ref, key_ref, dest_ref;
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char type[32], *description;
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long dlen, ret;
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long ret;
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/* pull the type and description into kernel space */
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ret = strncpy_from_user(type, _type, sizeof(type) - 1);
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ret = key_get_type_from_user(type, _type, sizeof(type));
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if (ret < 0)
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goto error;
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type[31] = '\0';
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ret = -EFAULT;
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dlen = strnlen_user(_description, PAGE_SIZE - 1);
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if (dlen <= 0)
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description = strndup_user(_description, PAGE_SIZE);
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if (IS_ERR(description)) {
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ret = PTR_ERR(description);
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goto error;
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ret = -EINVAL;
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if (dlen > PAGE_SIZE - 1)
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goto error;
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ret = -ENOMEM;
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description = kmalloc(dlen + 1, GFP_KERNEL);
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if (!description)
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goto error;
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description[dlen] = '\0';
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ret = -EFAULT;
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if (copy_from_user(description, _description, dlen) != 0)
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goto error2;
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}
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/* get the keyring at which to begin the search */
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keyring_ref = lookup_user_key(NULL, ringid, 0, 0, KEY_SEARCH);
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