Merge tag 'io_uring-6.16-20250619' of git://git.kernel.dk/linux

Pull io_uring fixes from Jens Axboe:

 - Two fixes for error injection failures. One fixes a task leak issue
   introduced in this merge window, the other an older issue with
   handling allocation of a mapped buffer.

 - Fix for a syzbot issue that triggers a kmalloc warning on attempting
   an allocation that's too large

 - Fix for an error injection failure causing a double put of a task,
   introduced in this merge window

* tag 'io_uring-6.16-20250619' of git://git.kernel.dk/linux:
  io_uring: fix potential page leak in io_sqe_buffer_register()
  io_uring/sqpoll: don't put task_struct on tctx setup failure
  io_uring: remove duplicate io_uring_alloc_task_context() definition
  io_uring: fix task leak issue in io_wq_create()
  io_uring/rsrc: validate buffer count with offset for cloning

Author: torvalds

io_uring/io-wq.c

@@ -1259,8 +1259,10 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
 	atomic_set(&wq->worker_refs, 1);
 	init_completion(&wq->worker_done);
 	ret = cpuhp_state_add_instance_nocalls(io_wq_online, &wq->cpuhp_node);
-	if (ret)
+	if (ret) {
+		put_task_struct(wq->task);
 		goto err;
+	}
 
 	return wq;
 err:

io_uring/io_uring.h

@@ -98,8 +98,6 @@ struct llist_node *io_handle_tw_list(struct llist_node *node, unsigned int *coun
 struct llist_node *tctx_task_work_run(struct io_uring_task *tctx, unsigned int max_entries, unsigned int *count);
 void tctx_task_work(struct callback_head *cb);
 __cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd);
-int io_uring_alloc_task_context(struct task_struct *task,
-				struct io_ring_ctx *ctx);
 
 int io_ring_add_registered_file(struct io_uring_task *tctx, struct file *file,
 				     int start, int end);

io_uring/rsrc.c

@@ -809,10 +809,8 @@ static struct io_rsrc_node *io_sqe_buffer_register(struct io_ring_ctx *ctx,
 
 	imu->nr_bvecs = nr_pages;
 	ret = io_buffer_account_pin(ctx, pages, nr_pages, imu, last_hpage);
-	if (ret) {
-		unpin_user_pages(pages, nr_pages);
+	if (ret)
 		goto done;
-	}
 
 	size = iov->iov_len;
 	/* store original address for later verification */
@@ -842,6 +840,8 @@ static struct io_rsrc_node *io_sqe_buffer_register(struct io_ring_ctx *ctx,
 	if (ret) {
 		if (imu)
 			io_free_imu(ctx, imu);
+		if (pages)
+			unpin_user_pages(pages, nr_pages);
 		io_cache_free(&ctx->node_cache, node);
 		node = ERR_PTR(ret);
 	}
@@ -1177,6 +1177,8 @@ static int io_clone_buffers(struct io_ring_ctx *ctx, struct io_ring_ctx *src_ctx
 		return -EINVAL;
 	if (check_add_overflow(arg->nr, arg->dst_off, &nbufs))
 		return -EOVERFLOW;
+	if (nbufs > IORING_MAX_REG_BUFFERS)
+		return -EINVAL;
 
 	ret = io_rsrc_data_alloc(&data, max(nbufs, ctx->buf_table.nr));
 	if (ret)

io_uring/sqpoll.c

@@ -16,6 +16,7 @@
 #include <uapi/linux/io_uring.h>
 
 #include "io_uring.h"
+#include "tctx.h"
 #include "napi.h"
 #include "sqpoll.h"
 
@@ -419,7 +420,6 @@ void io_sqpoll_wait_sq(struct io_ring_ctx *ctx)
 __cold int io_sq_offload_create(struct io_ring_ctx *ctx,
 				struct io_uring_params *p)
 {
-	struct task_struct *task_to_put = NULL;
 	int ret;
 
 	/* Retain compatibility with failing for an invalid attach attempt */
@@ -498,7 +498,7 @@ __cold int io_sq_offload_create(struct io_ring_ctx *ctx,
 		rcu_assign_pointer(sqd->thread, tsk);
 		mutex_unlock(&sqd->lock);
 
-		task_to_put = get_task_struct(tsk);
+		get_task_struct(tsk);
 		ret = io_uring_alloc_task_context(tsk, ctx);
 		wake_up_new_task(tsk);
 		if (ret)
@@ -513,8 +513,6 @@ __cold int io_sq_offload_create(struct io_ring_ctx *ctx,
 	complete(&ctx->sq_data->exited);
 err:
 	io_sq_thread_finish(ctx);
-	if (task_to_put)
-		put_task_struct(task_to_put);
 	return ret;
 }