Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

1 files changed, 374 insertions, 0 deletions

diff --git a/security/keys/gc.c b/security/keys/gc.c
new file mode 100644
index 000000000..748e83818
--- /dev/null
+++ b/security/keys/gc.c
@@ -0,0 +1,374 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Key garbage collector
+ *
+ * Copyright (C) 2009-2011 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/slab.h>
+#include <linux/security.h>
+#include <keys/keyring-type.h>
+#include "internal.h"
+
+/*
+ * Delay between key revocation/expiry in seconds
+ */
+unsigned key_gc_delay = 5 * 60;
+
+/*
+ * Reaper for unused keys.
+ */
+static void key_garbage_collector(struct work_struct *work);
+DECLARE_WORK(key_gc_work, key_garbage_collector);
+
+/*
+ * Reaper for links from keyrings to dead keys.
+ */
+static void key_gc_timer_func(struct timer_list *);
+static DEFINE_TIMER(key_gc_timer, key_gc_timer_func);
+
+static time64_t key_gc_next_run = TIME64_MAX;
+static struct key_type *key_gc_dead_keytype;
+
+static unsigned long key_gc_flags;
+#define KEY_GC_KEY_EXPIRED	0	/* A key expired and needs unlinking */
+#define KEY_GC_REAP_KEYTYPE	1	/* A keytype is being unregistered */
+#define KEY_GC_REAPING_KEYTYPE	2	/* Cleared when keytype reaped */
+
+
+/*
+ * Any key whose type gets unregistered will be re-typed to this if it can't be
+ * immediately unlinked.
+ */
+struct key_type key_type_dead = {
+	.name = ".dead",
+};
+
+/*
+ * Schedule a garbage collection run.
+ * - time precision isn't particularly important
+ */
+void key_schedule_gc(time64_t gc_at)
+{
+	unsigned long expires;
+	time64_t now = ktime_get_real_seconds();
+
+	kenter("%lld", gc_at - now);
+
+	if (gc_at <= now || test_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags)) {
+		kdebug("IMMEDIATE");
+		schedule_work(&key_gc_work);
+	} else if (gc_at < key_gc_next_run) {
+		kdebug("DEFERRED");
+		key_gc_next_run = gc_at;
+		expires = jiffies + (gc_at - now) * HZ;
+		mod_timer(&key_gc_timer, expires);
+	}
+}
+
+/*
+ * Set the expiration time on a key.
+ */
+void key_set_expiry(struct key *key, time64_t expiry)
+{
+	key->expiry = expiry;
+	if (expiry != TIME64_MAX) {
+		if (!(key->type->flags & KEY_TYPE_INSTANT_REAP))
+			expiry += key_gc_delay;
+		key_schedule_gc(expiry);
+	}
+}
+
+/*
+ * Schedule a dead links collection run.
+ */
+void key_schedule_gc_links(void)
+{
+	set_bit(KEY_GC_KEY_EXPIRED, &key_gc_flags);
+	schedule_work(&key_gc_work);
+}
+
+/*
+ * Some key's cleanup time was met after it expired, so we need to get the
+ * reaper to go through a cycle finding expired keys.
+ */
+static void key_gc_timer_func(struct timer_list *unused)
+{
+	kenter("");
+	key_gc_next_run = TIME64_MAX;
+	key_schedule_gc_links();
+}
+
+/*
+ * Reap keys of dead type.
+ *
+ * We use three flags to make sure we see three complete cycles of the garbage
+ * collector: the first to mark keys of that type as being dead, the second to
+ * collect dead links and the third to clean up the dead keys.  We have to be
+ * careful as there may already be a cycle in progress.
+ *
+ * The caller must be holding key_types_sem.
+ */
+void key_gc_keytype(struct key_type *ktype)
+{
+	kenter("%s", ktype->name);
+
+	key_gc_dead_keytype = ktype;
+	set_bit(KEY_GC_REAPING_KEYTYPE, &key_gc_flags);
+	smp_mb();
+	set_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags);
+
+	kdebug("schedule");
+	schedule_work(&key_gc_work);
+
+	kdebug("sleep");
+	wait_on_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE,
+		    TASK_UNINTERRUPTIBLE);
+
+	key_gc_dead_keytype = NULL;
+	kleave("");
+}
+
+/*
+ * Garbage collect a list of unreferenced, detached keys
+ */
+static noinline void key_gc_unused_keys(struct list_head *keys)
+{
+	while (!list_empty(keys)) {
+		struct key *key =
+			list_entry(keys->next, struct key, graveyard_link);
+		short state = key->state;
+
+		list_del(&key->graveyard_link);
+
+		kdebug("- %u", key->serial);
+		key_check(key);
+
+#ifdef CONFIG_KEY_NOTIFICATIONS
+		remove_watch_list(key->watchers, key->serial);
+		key->watchers = NULL;
+#endif
+
+		/* Throw away the key data if the key is instantiated */
+		if (state == KEY_IS_POSITIVE && key->type->destroy)
+			key->type->destroy(key);
+
+		security_key_free(key);
+
+		atomic_dec(&key->user->nkeys);
+		if (state != KEY_IS_UNINSTANTIATED)
+			atomic_dec(&key->user->nikeys);
+
+		key_user_put(key->user);
+		key_put_tag(key->domain_tag);
+		kfree(key->description);
+
+		memzero_explicit(key, sizeof(*key));
+		kmem_cache_free(key_jar, key);
+	}
+}
+
+/*
+ * Garbage collector for unused keys.
+ *
+ * This is done in process context so that we don't have to disable interrupts
+ * all over the place.  key_put() schedules this rather than trying to do the
+ * cleanup itself, which means key_put() doesn't have to sleep.
+ */
+static void key_garbage_collector(struct work_struct *work)
+{
+	static LIST_HEAD(graveyard);
+	static u8 gc_state;		/* Internal persistent state */
+#define KEY_GC_REAP_AGAIN	0x01	/* - Need another cycle */
+#define KEY_GC_REAPING_LINKS	0x02	/* - We need to reap links */
+#define KEY_GC_REAPING_DEAD_1	0x10	/* - We need to mark dead keys */
+#define KEY_GC_REAPING_DEAD_2	0x20	/* - We need to reap dead key links */
+#define KEY_GC_REAPING_DEAD_3	0x40	/* - We need to reap dead keys */
+#define KEY_GC_FOUND_DEAD_KEY	0x80	/* - We found at least one dead key */
+
+	struct rb_node *cursor;
+	struct key *key;
+	time64_t new_timer, limit, expiry;
+
+	kenter("[%lx,%x]", key_gc_flags, gc_state);
+
+	limit = ktime_get_real_seconds();
+
+	/* Work out what we're going to be doing in this pass */
+	gc_state &= KEY_GC_REAPING_DEAD_1 | KEY_GC_REAPING_DEAD_2;
+	gc_state <<= 1;
+	if (test_and_clear_bit(KEY_GC_KEY_EXPIRED, &key_gc_flags))
+		gc_state |= KEY_GC_REAPING_LINKS;
+
+	if (test_and_clear_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags))
+		gc_state |= KEY_GC_REAPING_DEAD_1;
+	kdebug("new pass %x", gc_state);
+
+	new_timer = TIME64_MAX;
+
+	/* As only this function is permitted to remove things from the key
+	 * serial tree, if cursor is non-NULL then it will always point to a
+	 * valid node in the tree - even if lock got dropped.
+	 */
+	spin_lock(&key_serial_lock);
+	cursor = rb_first(&key_serial_tree);
+
+continue_scanning:
+	while (cursor) {
+		key = rb_entry(cursor, struct key, serial_node);
+		cursor = rb_next(cursor);
+
+		if (!test_bit_acquire(KEY_FLAG_USER_ALIVE, &key->flags)) {
+			/* Clobber key->user after final put seen. */
+			goto found_unreferenced_key;
+		}
+
+		if (unlikely(gc_state & KEY_GC_REAPING_DEAD_1)) {
+			if (key->type == key_gc_dead_keytype) {
+				gc_state |= KEY_GC_FOUND_DEAD_KEY;
+				set_bit(KEY_FLAG_DEAD, &key->flags);
+				key->perm = 0;
+				goto skip_dead_key;
+			} else if (key->type == &key_type_keyring &&
+				   key->restrict_link) {
+				goto found_restricted_keyring;
+			}
+		}
+
+		expiry = key->expiry;
+		if (expiry != TIME64_MAX) {
+			if (!(key->type->flags & KEY_TYPE_INSTANT_REAP))
+				expiry += key_gc_delay;
+			if (expiry > limit && expiry < new_timer) {
+				kdebug("will expire %x in %lld",
+				       key_serial(key), key->expiry - limit);
+				new_timer = key->expiry;
+			}
+		}
+
+		if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2))
+			if (key->type == key_gc_dead_keytype)
+				gc_state |= KEY_GC_FOUND_DEAD_KEY;
+
+		if ((gc_state & KEY_GC_REAPING_LINKS) ||
+		    unlikely(gc_state & KEY_GC_REAPING_DEAD_2)) {
+			if (key->type == &key_type_keyring)
+				goto found_keyring;
+		}
+
+		if (unlikely(gc_state & KEY_GC_REAPING_DEAD_3))
+			if (key->type == key_gc_dead_keytype)
+				goto destroy_dead_key;
+
+	skip_dead_key:
+		if (spin_is_contended(&key_serial_lock) || need_resched())
+			goto contended;
+	}
+
+contended:
+	spin_unlock(&key_serial_lock);
+
+maybe_resched:
+	if (cursor) {
+		cond_resched();
+		spin_lock(&key_serial_lock);
+		goto continue_scanning;
+	}
+
+	/* We've completed the pass.  Set the timer if we need to and queue a
+	 * new cycle if necessary.  We keep executing cycles until we find one
+	 * where we didn't reap any keys.
+	 */
+	kdebug("pass complete");
+
+	if (new_timer != TIME64_MAX) {
+		new_timer += key_gc_delay;
+		key_schedule_gc(new_timer);
+	}
+
+	if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2) ||
+	    !list_empty(&graveyard)) {
+		/* Make sure that all pending keyring payload destructions are
+		 * fulfilled and that people aren't now looking at dead or
+		 * dying keys that they don't have a reference upon or a link
+		 * to.
+		 */
+		kdebug("gc sync");
+		synchronize_rcu();
+	}
+
+	if (!list_empty(&graveyard)) {
+		kdebug("gc keys");
+		key_gc_unused_keys(&graveyard);
+	}
+
+	if (unlikely(gc_state & (KEY_GC_REAPING_DEAD_1 |
+				 KEY_GC_REAPING_DEAD_2))) {
+		if (!(gc_state & KEY_GC_FOUND_DEAD_KEY)) {
+			/* No remaining dead keys: short circuit the remaining
+			 * keytype reap cycles.
+			 */
+			kdebug("dead short");
+			gc_state &= ~(KEY_GC_REAPING_DEAD_1 | KEY_GC_REAPING_DEAD_2);
+			gc_state |= KEY_GC_REAPING_DEAD_3;
+		} else {
+			gc_state |= KEY_GC_REAP_AGAIN;
+		}
+	}
+
+	if (unlikely(gc_state & KEY_GC_REAPING_DEAD_3)) {
+		kdebug("dead wake");
+		smp_mb();
+		clear_bit(KEY_GC_REAPING_KEYTYPE, &key_gc_flags);
+		wake_up_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE);
+	}
+
+	if (gc_state & KEY_GC_REAP_AGAIN)
+		schedule_work(&key_gc_work);
+	kleave(" [end %x]", gc_state);
+	return;
+
+	/* We found an unreferenced key - once we've removed it from the tree,
+	 * we can safely drop the lock.
+	 */
+found_unreferenced_key:
+	kdebug("unrefd key %d", key->serial);
+	rb_erase(&key->serial_node, &key_serial_tree);
+	spin_unlock(&key_serial_lock);
+
+	list_add_tail(&key->graveyard_link, &graveyard);
+	gc_state |= KEY_GC_REAP_AGAIN;
+	goto maybe_resched;
+
+	/* We found a restricted keyring and need to update the restriction if
+	 * it is associated with the dead key type.
+	 */
+found_restricted_keyring:
+	spin_unlock(&key_serial_lock);
+	keyring_restriction_gc(key, key_gc_dead_keytype);
+	goto maybe_resched;
+
+	/* We found a keyring and we need to check the payload for links to
+	 * dead or expired keys.  We don't flag another reap immediately as we
+	 * have to wait for the old payload to be destroyed by RCU before we
+	 * can reap the keys to which it refers.
+	 */
+found_keyring:
+	spin_unlock(&key_serial_lock);
+	keyring_gc(key, limit);
+	goto maybe_resched;
+
+	/* We found a dead key that is still referenced.  Reset its type and
+	 * destroy its payload with its semaphore held.
+	 */
+destroy_dead_key:
+	spin_unlock(&key_serial_lock);
+	kdebug("destroy key %d", key->serial);
+	down_write(&key->sem);
+	key->type = &key_type_dead;
+	if (key_gc_dead_keytype->destroy)
+		key_gc_dead_keytype->destroy(key);
+	memset(&key->payload, KEY_DESTROY, sizeof(key->payload));
+	up_write(&key->sem);
+	goto maybe_resched;
+}