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>
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 6361d37..2ab3885 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -77,8 +77,6 @@
extern wait_queue_head_t request_key_conswq;
-extern void keyring_publish_name(struct key *keyring);
-
extern int __key_link(struct key *keyring, struct key *key);
extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
@@ -102,7 +100,7 @@
key_match_func_t match,
struct task_struct *tsk);
-extern struct key *find_keyring_by_name(const char *name, key_serial_t bound);
+extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
extern int install_thread_keyring(struct task_struct *tsk);
extern int install_process_keyring(struct task_struct *tsk);