Merge tag 'io_uring-6.19-20260122' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull io_uring fixes from Jens Axboe:

 - Fix for a potential leak of an iovec, if a specific cleanup path is
   used and the rw_cache is full at the time of the call

 - Fix for a regression added in this cycle, where waitid should be
   using prober release/acquire semantics for updating the wait queue
   head

 - Check for the cancelation bit being set for every work item processed
   by io-wq, not just at the start of the loop. Has no real practical
   implications other than to shut up syzbot doing crazy things that
   grossly overload a system, hence slowing down ring exit

 - A few selftest additions, updating the mini_liburing that selftests
   use

* tag 'io_uring-6.19-20260122' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  selftests/io_uring: support NO_SQARRAY in miniliburing
  selftests/io_uring: add io_uring_queue_init_params
  io_uring/io-wq: check IO_WQ_BIT_EXIT inside work run loop
  io_uring/waitid: fix KCSAN warning on io_waitid->head
  io_uring/rw: free potentially allocated iovec on cache put failure

Author: torvalds

io_uring/io-wq.c

@@ -598,9 +598,9 @@ static void io_worker_handle_work(struct io_wq_acct *acct,
 	__releases(&acct->lock)
 {
 	struct io_wq *wq = worker->wq;
-	bool do_kill = test_bit(IO_WQ_BIT_EXIT, &wq->state);
 
 	do {
+		bool do_kill = test_bit(IO_WQ_BIT_EXIT, &wq->state);
 		struct io_wq_work *work;
 
 		/*

io_uring/rw.c

@@ -144,19 +144,22 @@ static inline int io_import_rw_buffer(int rw, struct io_kiocb *req,
 	return 0;
 }
 
-static void io_rw_recycle(struct io_kiocb *req, unsigned int issue_flags)
+static bool io_rw_recycle(struct io_kiocb *req, unsigned int issue_flags)
 {
 	struct io_async_rw *rw = req->async_data;
 
 	if (unlikely(issue_flags & IO_URING_F_UNLOCKED))
-		return;
+		return false;
 
 	io_alloc_cache_vec_kasan(&rw->vec);
 	if (rw->vec.nr > IO_VEC_CACHE_SOFT_CAP)
 		io_vec_free(&rw->vec);
 
-	if (io_alloc_cache_put(&req->ctx->rw_cache, rw))
+	if (io_alloc_cache_put(&req->ctx->rw_cache, rw)) {
 		io_req_async_data_clear(req, 0);
+		return true;
+	}
+	return false;
 }
 
 static void io_req_rw_cleanup(struct io_kiocb *req, unsigned int issue_flags)
@@ -190,7 +193,11 @@ static void io_req_rw_cleanup(struct io_kiocb *req, unsigned int issue_flags)
 	 */
 	if (!(req->flags & (REQ_F_REISSUE | REQ_F_REFCOUNT))) {
 		req->flags &= ~REQ_F_NEED_CLEANUP;
-		io_rw_recycle(req, issue_flags);
+		if (!io_rw_recycle(req, issue_flags)) {
+			struct io_async_rw *rw = req->async_data;
+
+			io_vec_free(&rw->vec);
+		}
 	}
 }
 

io_uring/waitid.c

@@ -114,11 +114,11 @@ static void io_waitid_remove_wq(struct io_kiocb *req)
 	struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid);
 	struct wait_queue_head *head;
 
-	head = READ_ONCE(iw->head);
+	head = smp_load_acquire(&iw->head);
 	if (head) {
 		struct io_waitid_async *iwa = req->async_data;
 
-		iw->head = NULL;
+		smp_store_release(&iw->head, NULL);
 		spin_lock_irq(&head->lock);
 		list_del_init(&iwa->wo.child_wait.entry);
 		spin_unlock_irq(&head->lock);
@@ -246,7 +246,7 @@ static int io_waitid_wait(struct wait_queue_entry *wait, unsigned mode,
 		return 0;
 
 	list_del_init(&wait->entry);
-	iw->head = NULL;
+	smp_store_release(&iw->head, NULL);
 
 	/* cancel is in progress */
 	if (atomic_fetch_inc(&iw->refs) & IO_WAITID_REF_MASK)

tools/include/io_uring/mini_liburing.h

@@ -6,6 +6,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
+#include <sys/uio.h>
 
 struct io_sq_ring {
 	unsigned int *head;
@@ -55,6 +56,7 @@ struct io_uring {
 	struct io_uring_sq sq;
 	struct io_uring_cq cq;
 	int ring_fd;
+	unsigned flags;
 };
 
 #if defined(__x86_64) || defined(__i386__)
@@ -72,7 +74,14 @@ static inline int io_uring_mmap(int fd, struct io_uring_params *p,
 	void *ptr;
 	int ret;
 
-	sq->ring_sz = p->sq_off.array + p->sq_entries * sizeof(unsigned int);
+	if (p->flags & IORING_SETUP_NO_SQARRAY) {
+		sq->ring_sz = p->cq_off.cqes;
+		sq->ring_sz += p->cq_entries * sizeof(struct io_uring_cqe);
+	} else {
+		sq->ring_sz = p->sq_off.array;
+		sq->ring_sz += p->sq_entries * sizeof(unsigned int);
+	}
+
 	ptr = mmap(0, sq->ring_sz, PROT_READ | PROT_WRITE,
 		   MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_SQ_RING);
 	if (ptr == MAP_FAILED)
@@ -83,7 +92,8 @@ static inline int io_uring_mmap(int fd, struct io_uring_params *p,
 	sq->kring_entries = ptr + p->sq_off.ring_entries;
 	sq->kflags = ptr + p->sq_off.flags;
 	sq->kdropped = ptr + p->sq_off.dropped;
-	sq->array = ptr + p->sq_off.array;
+	if (!(p->flags & IORING_SETUP_NO_SQARRAY))
+		sq->array = ptr + p->sq_off.array;
 
 	size = p->sq_entries * sizeof(struct io_uring_sqe);
 	sq->sqes = mmap(0, size, PROT_READ | PROT_WRITE,
@@ -126,28 +136,39 @@ static inline int io_uring_enter(int fd, unsigned int to_submit,
 		       flags, sig, _NSIG / 8);
 }
 
-static inline int io_uring_queue_init(unsigned int entries,
-				      struct io_uring *ring,
-				      unsigned int flags)
+static inline int io_uring_queue_init_params(unsigned int entries,
+					     struct io_uring *ring,
+					     struct io_uring_params *p)
 {
-	struct io_uring_params p;
 	int fd, ret;
 
 	memset(ring, 0, sizeof(*ring));
-	memset(&p, 0, sizeof(p));
-	p.flags = flags;
 
-	fd = io_uring_setup(entries, &p);
+	fd = io_uring_setup(entries, p);
 	if (fd < 0)
 		return fd;
-	ret = io_uring_mmap(fd, &p, &ring->sq, &ring->cq);
-	if (!ret)
+	ret = io_uring_mmap(fd, p, &ring->sq, &ring->cq);
+	if (!ret) {
 		ring->ring_fd = fd;
-	else
+		ring->flags = p->flags;
+	} else {
 		close(fd);
+	}
 	return ret;
 }
 
+static inline int io_uring_queue_init(unsigned int entries,
+				      struct io_uring *ring,
+				      unsigned int flags)
+{
+	struct io_uring_params p;
+
+	memset(&p, 0, sizeof(p));
+	p.flags = flags;
+
+	return io_uring_queue_init_params(entries, ring, &p);
+}
+
 /* Get a sqe */
 static inline struct io_uring_sqe *io_uring_get_sqe(struct io_uring *ring)
 {
@@ -199,10 +220,18 @@ static inline int io_uring_submit(struct io_uring *ring)
 
 	ktail = *sq->ktail;
 	to_submit = sq->sqe_tail - sq->sqe_head;
-	for (submitted = 0; submitted < to_submit; submitted++) {
-		read_barrier();
-		sq->array[ktail++ & mask] = sq->sqe_head++ & mask;
+
+	if (!(ring->flags & IORING_SETUP_NO_SQARRAY)) {
+		for (submitted = 0; submitted < to_submit; submitted++) {
+			read_barrier();
+			sq->array[ktail++ & mask] = sq->sqe_head++ & mask;
+		}
+	} else {
+		ktail += to_submit;
+		sq->sqe_head += to_submit;
+		submitted = to_submit;
 	}
+
 	if (!submitted)
 		return 0;