Merge tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linuxgrafted

Pull io_uring fixes from Jens Axboe:

 - Fix a task_work add use-after-free with SQPOLL.

   The sqpoll thread could pop and complete the last request while
   io_req_normal_work_add() was still looking at them after the mpscq
   push.

   Use the same approach as DEFER_TASKRUN to protect from that, holding
   an RCU read lock across the add, and have exit wait for an RCU grace
   period for SQPOLL rings as well.

 - CQE32 ring fixes: correct the free entry check for 32b CQEs, zero the
   big_cqe for aux CQEs, and only post the dummy skip CQE on CQE_MIXED
   rings

 - Mark the source filter table as COW when cloning bpf filters, so
   registering another filter on the source doesn't modify the shared
   table in place

 - Initialize the task context before running the BPF loop

 - Requeue zcrx multishot receives stopped by a local resource

 - End a TX_TIMESTAMP multishot cmd when the CQ is full (lollipopkit)

* tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring: fix task_work add use-after-free with SQPOLL
  io_uring/cmd_net: end TX_TIMESTAMP multishot when the CQ is full
  io_uring/zcrx: requeue multishot receives stopped by a local resource
  io_uring: initialize task context before running the BPF loop
  io_uring: zero big_cqe for aux CQEs on CQE32 rings
  io_uring: fix free entry check for 32b CQEs on CQE32 rings
  io_uring: only post the dummy skip CQE on CQE_MIXED rings
  io_uring/bpf_filter: mark source as COW when cloning filters

1 files changed, 91 insertions, 0 deletions

diff --git a/security/landlock/object.h b/security/landlock/object.h
new file mode 100644
index 000000000..5f28c35e8
--- /dev/null
+++ b/security/landlock/object.h
@@ -0,0 +1,91 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Landlock LSM - Object management
+ *
+ * Copyright © 2016-2020 Mickaël Salaün <mic@digikod.net>
+ * Copyright © 2018-2020 ANSSI
+ */
+
+#ifndef _SECURITY_LANDLOCK_OBJECT_H
+#define _SECURITY_LANDLOCK_OBJECT_H
+
+#include <linux/compiler_types.h>
+#include <linux/refcount.h>
+#include <linux/spinlock.h>
+
+struct landlock_object;
+
+/**
+ * struct landlock_object_underops - Operations on an underlying object
+ */
+struct landlock_object_underops {
+	/**
+	 * @release: Releases the underlying object (e.g. iput() for an inode).
+	 */
+	void (*release)(struct landlock_object *const object)
+		__releases(object->lock);
+};
+
+/**
+ * struct landlock_object - Security blob tied to a kernel object
+ *
+ * The goal of this structure is to enable to tie a set of ephemeral access
+ * rights (pertaining to different domains) to a kernel object (e.g an inode)
+ * in a safe way.  This implies to handle concurrent use and modification.
+ *
+ * The lifetime of a &struct landlock_object depends on the rules referring to
+ * it.
+ */
+struct landlock_object {
+	/**
+	 * @usage: This counter is used to tie an object to the rules matching
+	 * it or to keep it alive while adding a new rule.  If this counter
+	 * reaches zero, this struct must not be modified, but this counter can
+	 * still be read from within an RCU read-side critical section.  When
+	 * adding a new rule to an object with a usage counter of zero, we must
+	 * wait until the pointer to this object is set to NULL (or recycled).
+	 */
+	refcount_t usage;
+	/**
+	 * @lock: Protects against concurrent modifications.  This lock must be
+	 * held from the time @usage drops to zero until any weak references
+	 * from @underobj to this object have been cleaned up.
+	 *
+	 * Lock ordering: inode->i_lock nests inside this.
+	 */
+	spinlock_t lock;
+	/**
+	 * @underobj: Used when cleaning up an object and to mark an object as
+	 * tied to its underlying kernel structure.  This pointer is protected
+	 * by @lock.  Cf. landlock_release_inodes() and release_inode().
+	 */
+	void *underobj;
+	union {
+		/**
+		 * @rcu_free: Enables lockless use of @usage, @lock and
+		 * @underobj from within an RCU read-side critical section.
+		 * @rcu_free and @underops are only used by
+		 * landlock_put_object().
+		 */
+		struct rcu_head rcu_free;
+		/**
+		 * @underops: Enables landlock_put_object() to release the
+		 * underlying object (e.g. inode).
+		 */
+		const struct landlock_object_underops *underops;
+	};
+};
+
+struct landlock_object *
+landlock_create_object(const struct landlock_object_underops *const underops,
+		       void *const underobj);
+
+void landlock_put_object(struct landlock_object *const object);
+
+static inline void landlock_get_object(struct landlock_object *const object)
+{
+	if (object)
+		refcount_inc(&object->usage);
+}
+
+#endif /* _SECURITY_LANDLOCK_OBJECT_H */