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author | David Howells <dhowells@redhat.com> | 2011-06-17 11:25:59 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-06-17 09:40:48 -0700 |
commit | 879669961b11e7f40b518784863a259f735a72bf (patch) | |
tree | 9bff5392e365caf656c9dd9be38f7471c182278c /security/keys | |
parent | eb96c925152fc289311e5d7e956b919e9b60ab53 (diff) | |
download | linux-stable-879669961b11e7f40b518784863a259f735a72bf.tar.gz linux-stable-879669961b11e7f40b518784863a259f735a72bf.tar.bz2 linux-stable-879669961b11e7f40b518784863a259f735a72bf.zip |
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')
-rw-r--r-- | security/keys/request_key.c | 3 |
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); * This is called in context of freshly forked kthread before kernel_execve(), * so we can simply install the desired session_keyring at this point. */ -static int umh_keys_init(struct subprocess_info *info) +static int umh_keys_init(struct subprocess_info *info, struct cred *cred) { - struct cred *cred = (struct cred*)current_cred(); struct key *keyring = info->data; return install_session_keyring_to_cred(cred, keyring); |