diff options
| author | David Howells <dhowells@redhat.com> | 2008-04-29 01:01:31 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-29 08:06:17 -0700 |
| commit | 69664cf16af4f31cd54d77948a4baf9c7e0ca7b9 (patch) | |
| tree | 3ff4ecae21c140a2beed25cfa9e55b788f9814ac /kernel/user.c | |
| parent | 6b79ccb5144f9ffb4d4596c23e7570238dd12abc (diff) | |
| download | linux-69664cf16af4f31cd54d77948a4baf9c7e0ca7b9.tar.gz | |
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 'kernel/user.c')
| -rw-r--r-- | kernel/user.c | 15 |
1 files changed, 4 insertions, 11 deletions
diff --git a/kernel/user.c b/kernel/user.c index debce602bfdd..aefbbfa3159f 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -53,10 +53,6 @@ struct user_struct root_user = { .files = ATOMIC_INIT(0), .sigpending = ATOMIC_INIT(0), .locked_shm = 0, -#ifdef CONFIG_KEYS - .uid_keyring = &root_user_keyring, - .session_keyring = &root_session_keyring, -#endif #ifdef CONFIG_USER_SCHED .tg = &init_task_group, #endif @@ -420,12 +416,12 @@ struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid) new->mq_bytes = 0; #endif new->locked_shm = 0; - - if (alloc_uid_keyring(new, current) < 0) - goto out_free_user; +#ifdef CONFIG_KEYS + new->uid_keyring = new->session_keyring = NULL; +#endif if (sched_create_user(new) < 0) - goto out_put_keys; + goto out_free_user; if (uids_user_create(new)) goto out_destoy_sched; @@ -459,9 +455,6 @@ struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid) out_destoy_sched: sched_destroy_user(new); -out_put_keys: - key_put(new->uid_keyring); - key_put(new->session_keyring); out_free_user: kmem_cache_free(uid_cachep, new); out_unlock: |