aboutsummaryrefslogtreecommitdiffstats
path: root/security/keys/request_key.c
diff options
context:
space:
mode:
authorDavid Howells <dhowells@redhat.com>2011-06-17 06:25:59 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2011-06-17 12:40:48 -0400
commit879669961b11e7f40b518784863a259f735a72bf (patch)
tree9bff5392e365caf656c9dd9be38f7471c182278c /security/keys/request_key.c
parenteb96c925152fc289311e5d7e956b919e9b60ab53 (diff)
KEYS/DNS: Fix ____call_usermodehelper() to not lose the session keyring
____call_usermodehelper() now erases any credentials set by the subprocess_inf::init() function. The problem is that commit 17f60a7da150 ("capabilites: allow the application of capability limits to usermode helpers") creates and commits new credentials with prepare_kernel_cred() after the call to the init() function. This wipes all keyrings after umh_keys_init() is called. The best way to deal with this is to put the init() call just prior to the commit_creds() call, and pass the cred pointer to init(). That means that umh_keys_init() and suchlike can modify the credentials _before_ they are published and potentially in use by the rest of the system. This prevents request_key() from working as it is prevented from passing the session keyring it set up with the authorisation token to /sbin/request-key, and so the latter can't assume the authority to instantiate the key. This causes the in-kernel DNS resolver to fail with ENOKEY unconditionally. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Eric Paris <eparis@redhat.com> Tested-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'security/keys/request_key.c')
-rw-r--r--security/keys/request_key.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index d31862e0aa1c..8e319a416eec 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -71,9 +71,8 @@ EXPORT_SYMBOL(complete_request_key);
71 * This is called in context of freshly forked kthread before kernel_execve(), 71 * This is called in context of freshly forked kthread before kernel_execve(),
72 * so we can simply install the desired session_keyring at this point. 72 * so we can simply install the desired session_keyring at this point.
73 */ 73 */
74static int umh_keys_init(struct subprocess_info *info) 74static int umh_keys_init(struct subprocess_info *info, struct cred *cred)
75{ 75{
76 struct cred *cred = (struct cred*)current_cred();
77 struct key *keyring = info->data; 76 struct key *keyring = info->data;
78 77
79 return install_session_keyring_to_cred(cred, keyring); 78 return install_session_keyring_to_cred(cred, keyring);