aboutsummaryrefslogtreecommitdiff
path: root/security/keys
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-31 18:47:30 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-31 18:47:30 -0700
commitfb21affa49204acd409328415b49bfe90136653c (patch)
tree3535dbe0c0aad049a38cadfcffe78409397a1b32 /security/keys
parenta00b6151a2ae4c52576c35d3998e144a993d50b8 (diff)
parentf23ca335462e3c84f13270b9e65f83936068ec2c (diff)
downloadvexpress-lsk-fb21affa49204acd409328415b49bfe90136653c.tar.gz
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull second pile of signal handling patches from Al Viro: "This one is just task_work_add() series + remaining prereqs for it. There probably will be another pull request from that tree this cycle - at least for helpers, to get them out of the way for per-arch fixes remaining in the tree." Fix trivial conflict in kernel/irq/manage.c: the merge of Andrew's pile had brought in commit 97fd75b7b8e0 ("kernel/irq/manage.c: use the pr_foo() infrastructure to prefix printks") which changed one of the pr_err() calls that this merge moves around. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: keys: kill task_struct->replacement_session_keyring keys: kill the dummy key_replace_session_keyring() keys: change keyctl_session_to_parent() to use task_work_add() genirq: reimplement exit_irq_thread() hook via task_work_add() task_work_add: generic process-context callbacks avr32: missed _TIF_NOTIFY_RESUME on one of do_notify_resume callers parisc: need to check NOTIFY_RESUME when exiting from syscall move key_repace_session_keyring() into tracehook_notify_resume() TIF_NOTIFY_RESUME is defined on all targets now
Diffstat (limited to 'security/keys')
-rw-r--r--security/keys/internal.h2
-rw-r--r--security/keys/keyctl.c73
-rw-r--r--security/keys/process_keys.c20
3 files changed, 44 insertions, 51 deletions
diff --git a/security/keys/internal.h b/security/keys/internal.h
index f711b094ed4..3dcbf86b0d3 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -14,6 +14,7 @@
#include <linux/sched.h>
#include <linux/key-type.h>
+#include <linux/task_work.h>
#ifdef __KDEBUG
#define kenter(FMT, ...) \
@@ -148,6 +149,7 @@ extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
#define KEY_LOOKUP_FOR_UNLINK 0x04
extern long join_session_keyring(const char *name);
+extern void key_change_session_keyring(struct task_work *twork);
extern struct work_struct key_gc_work;
extern unsigned key_gc_delay;
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 21907ea35b1..0f5b3f02729 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1454,50 +1454,57 @@ long keyctl_get_security(key_serial_t keyid,
*/
long keyctl_session_to_parent(void)
{
-#ifdef TIF_NOTIFY_RESUME
struct task_struct *me, *parent;
const struct cred *mycred, *pcred;
- struct cred *cred, *oldcred;
+ struct task_work *newwork, *oldwork;
key_ref_t keyring_r;
+ struct cred *cred;
int ret;
keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_LINK);
if (IS_ERR(keyring_r))
return PTR_ERR(keyring_r);
+ ret = -ENOMEM;
+ newwork = kmalloc(sizeof(struct task_work), GFP_KERNEL);
+ if (!newwork)
+ goto error_keyring;
+
/* our parent is going to need a new cred struct, a new tgcred struct
* and new security data, so we allocate them here to prevent ENOMEM in
* our parent */
- ret = -ENOMEM;
cred = cred_alloc_blank();
if (!cred)
- goto error_keyring;
+ goto error_newwork;
cred->tgcred->session_keyring = key_ref_to_ptr(keyring_r);
- keyring_r = NULL;
+ init_task_work(newwork, key_change_session_keyring, cred);
me = current;
rcu_read_lock();
write_lock_irq(&tasklist_lock);
- parent = me->real_parent;
ret = -EPERM;
+ oldwork = NULL;
+ parent = me->real_parent;
/* the parent mustn't be init and mustn't be a kernel thread */
if (parent->pid <= 1 || !parent->mm)
- goto not_permitted;
+ goto unlock;
/* the parent must be single threaded */
if (!thread_group_empty(parent))
- goto not_permitted;
+ goto unlock;
/* the parent and the child must have different session keyrings or
* there's no point */
mycred = current_cred();
pcred = __task_cred(parent);
if (mycred == pcred ||
- mycred->tgcred->session_keyring == pcred->tgcred->session_keyring)
- goto already_same;
+ mycred->tgcred->session_keyring == pcred->tgcred->session_keyring) {
+ ret = 0;
+ goto unlock;
+ }
/* the parent must have the same effective ownership and mustn't be
* SUID/SGID */
@@ -1507,50 +1514,40 @@ long keyctl_session_to_parent(void)
pcred->gid != mycred->egid ||
pcred->egid != mycred->egid ||
pcred->sgid != mycred->egid)
- goto not_permitted;
+ goto unlock;
/* the keyrings must have the same UID */
if ((pcred->tgcred->session_keyring &&
pcred->tgcred->session_keyring->uid != mycred->euid) ||
mycred->tgcred->session_keyring->uid != mycred->euid)
- goto not_permitted;
+ goto unlock;
- /* if there's an already pending keyring replacement, then we replace
- * that */
- oldcred = parent->replacement_session_keyring;
+ /* cancel an already pending keyring replacement */
+ oldwork = task_work_cancel(parent, key_change_session_keyring);
/* the replacement session keyring is applied just prior to userspace
* restarting */
- parent->replacement_session_keyring = cred;
- cred = NULL;
- set_ti_thread_flag(task_thread_info(parent), TIF_NOTIFY_RESUME);
-
+ ret = task_work_add(parent, newwork, true);
+ if (!ret)
+ newwork = NULL;
+unlock:
write_unlock_irq(&tasklist_lock);
rcu_read_unlock();
- if (oldcred)
- put_cred(oldcred);
- return 0;
-
-already_same:
- ret = 0;
-not_permitted:
- write_unlock_irq(&tasklist_lock);
- rcu_read_unlock();
- put_cred(cred);
+ if (oldwork) {
+ put_cred(oldwork->data);
+ kfree(oldwork);
+ }
+ if (newwork) {
+ put_cred(newwork->data);
+ kfree(newwork);
+ }
return ret;
+error_newwork:
+ kfree(newwork);
error_keyring:
key_ref_put(keyring_r);
return ret;
-
-#else /* !TIF_NOTIFY_RESUME */
- /*
- * To be removed when TIF_NOTIFY_RESUME has been implemented on
- * m68k/xtensa
- */
-#warning TIF_NOTIFY_RESUME not implemented
- return -EOPNOTSUPP;
-#endif /* !TIF_NOTIFY_RESUME */
}
/*
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index d71056db7b6..4ad54eea1ea 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -834,23 +834,17 @@ error:
* Replace a process's session keyring on behalf of one of its children when
* the target process is about to resume userspace execution.
*/
-void key_replace_session_keyring(void)
+void key_change_session_keyring(struct task_work *twork)
{
- const struct cred *old;
- struct cred *new;
-
- if (!current->replacement_session_keyring)
- return;
+ const struct cred *old = current_cred();
+ struct cred *new = twork->data;
- write_lock_irq(&tasklist_lock);
- new = current->replacement_session_keyring;
- current->replacement_session_keyring = NULL;
- write_unlock_irq(&tasklist_lock);
-
- if (!new)
+ kfree(twork);
+ if (unlikely(current->flags & PF_EXITING)) {
+ put_cred(new);
return;
+ }
- old = current_cred();
new-> uid = old-> uid;
new-> euid = old-> euid;
new-> suid = old-> suid;