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author | David Howells <dhowells@redhat.com> | 2008-04-29 01:01:31 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-29 08:06:17 -0700 |
commit | 69664cf16af4f31cd54d77948a4baf9c7e0ca7b9 (patch) | |
tree | 3ff4ecae21c140a2beed25cfa9e55b788f9814ac /security/keys/keyring.c | |
parent | 6b79ccb5144f9ffb4d4596c23e7570238dd12abc (diff) | |
download | linux-stable-69664cf16af4f31cd54d77948a4baf9c7e0ca7b9.tar.gz linux-stable-69664cf16af4f31cd54d77948a4baf9c7e0ca7b9.tar.bz2 linux-stable-69664cf16af4f31cd54d77948a4baf9c7e0ca7b9.zip |
keys: don't generate user and user session keyrings unless they're accessed
Don't generate the per-UID user and user session keyrings unless they're
explicitly accessed. This solves a problem during a login process whereby
set*uid() is called before the SELinux PAM module, resulting in the per-UID
keyrings having the wrong security labels.
This also cures the problem of multiple per-UID keyrings sometimes appearing
due to PAM modules (including pam_keyinit) setuiding and causing user_structs
to come into and go out of existence whilst the session keyring pins the user
keyring. This is achieved by first searching for extant per-UID keyrings
before inventing new ones.
The serial bound argument is also dropped from find_keyring_by_name() as it's
not currently made use of (setting it to 0 disables the feature).
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <kwc@citi.umich.edu>
Cc: <arunsr@cse.iitk.ac.in>
Cc: <dwalsh@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'security/keys/keyring.c')
-rw-r--r-- | security/keys/keyring.c | 19 |
1 files changed, 7 insertions, 12 deletions
diff --git a/security/keys/keyring.c b/security/keys/keyring.c index 70f0c313c888..a9ab8affc092 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -1,6 +1,6 @@ -/* keyring.c: keyring handling +/* Keyring handling * - * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2004-2005, 2008 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -79,7 +79,7 @@ static DECLARE_RWSEM(keyring_serialise_link_sem); * publish the name of a keyring so that it can be found by name (if it has * one) */ -void keyring_publish_name(struct key *keyring) +static void keyring_publish_name(struct key *keyring) { int bucket; @@ -516,10 +516,9 @@ key_ref_t __keyring_search_one(key_ref_t keyring_ref, /* * find a keyring with the specified name * - all named keyrings are searched - * - only find keyrings with search permission for the process - * - only find keyrings with a serial number greater than the one specified + * - normally only finds keyrings with search permission for the current process */ -struct key *find_keyring_by_name(const char *name, key_serial_t bound) +struct key *find_keyring_by_name(const char *name, bool skip_perm_check) { struct key *keyring; int bucket; @@ -545,15 +544,11 @@ struct key *find_keyring_by_name(const char *name, key_serial_t bound) if (strcmp(keyring->description, name) != 0) continue; - if (key_permission(make_key_ref(keyring, 0), + if (!skip_perm_check && + key_permission(make_key_ref(keyring, 0), KEY_SEARCH) < 0) continue; - /* found a potential candidate, but we still need to - * check the serial number */ - if (keyring->serial <= bound) - continue; - /* we've got a match */ atomic_inc(&keyring->usage); read_unlock(&keyring_name_lock); |