Merge tag 'io_uring-6.17-20250815' of git://git.kernel.dk/linux

Pull io_uring fixes from Jens Axboe:

 - Tweak for the fairly recent changes of minimizing io-wq worker
   creations when it's pointless to create them.

 - Fix for an issue with ring provided buffers, which could cause issues
   with reuse or corrupt application data.

* tag 'io_uring-6.17-20250815' of git://git.kernel.dk/linux:
  io_uring/io-wq: add check free worker before create new worker
  io_uring/net: commit partial buffers on retry

2 files changed, 23 insertions, 12 deletions

diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c
index be91edf34f01..17dfaa0395c4 100644
--- a/io_uring/io-wq.c
+++ b/io_uring/io-wq.c
@@ -357,6 +357,13 @@ static void create_worker_cb(struct callback_head *cb)
 	worker = container_of(cb, struct io_worker, create_work);
 	wq = worker->wq;
 	acct = worker->acct;
+
+	rcu_read_lock();
+	do_create = !io_acct_activate_free_worker(acct);
+	rcu_read_unlock();
+	if (!do_create)
+		goto no_need_create;
+
 	raw_spin_lock(&acct->workers_lock);
 
 	if (acct->nr_workers < acct->max_workers) {
@@ -367,6 +374,7 @@ static void create_worker_cb(struct callback_head *cb)
 	if (do_create) {
 		create_io_worker(wq, acct);
 	} else {
+no_need_create:
 		atomic_dec(&acct->nr_running);
 		io_worker_ref_put(wq);
 	}
diff --git a/io_uring/net.c b/io_uring/net.c
index dd96e355982f..d69f2afa4f7a 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -494,6 +494,15 @@ static int io_bundle_nbufs(struct io_async_msghdr *kmsg, int ret)
 	return nbufs;
 }
 
+static int io_net_kbuf_recyle(struct io_kiocb *req,
+			      struct io_async_msghdr *kmsg, int len)
+{
+	req->flags |= REQ_F_BL_NO_RECYCLE;
+	if (req->flags & REQ_F_BUFFERS_COMMIT)
+		io_kbuf_commit(req, req->buf_list, len, io_bundle_nbufs(kmsg, len));
+	return IOU_RETRY;
+}
+
 static inline bool io_send_finish(struct io_kiocb *req, int *ret,
 				  struct io_async_msghdr *kmsg,
 				  unsigned issue_flags)
@@ -562,8 +571,7 @@ int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
 			kmsg->msg.msg_controllen = 0;
 			kmsg->msg.msg_control = NULL;
 			sr->done_io += ret;
-			req->flags |= REQ_F_BL_NO_RECYCLE;
-			return -EAGAIN;
+			return io_net_kbuf_recyle(req, kmsg, ret);
 		}
 		if (ret == -ERESTARTSYS)
 			ret = -EINTR;
@@ -674,8 +682,7 @@ retry_bundle:
 			sr->len -= ret;
 			sr->buf += ret;
 			sr->done_io += ret;
-			req->flags |= REQ_F_BL_NO_RECYCLE;
-			return -EAGAIN;
+			return io_net_kbuf_recyle(req, kmsg, ret);
 		}
 		if (ret == -ERESTARTSYS)
 			ret = -EINTR;
@@ -1071,8 +1078,7 @@ retry_multishot:
 		}
 		if (ret > 0 && io_net_retry(sock, flags)) {
 			sr->done_io += ret;
-			req->flags |= REQ_F_BL_NO_RECYCLE;
-			return IOU_RETRY;
+			return io_net_kbuf_recyle(req, kmsg, ret);
 		}
 		if (ret == -ERESTARTSYS)
 			ret = -EINTR;
@@ -1218,8 +1224,7 @@ retry_multishot:
 			sr->len -= ret;
 			sr->buf += ret;
 			sr->done_io += ret;
-			req->flags |= REQ_F_BL_NO_RECYCLE;
-			return -EAGAIN;
+			return io_net_kbuf_recyle(req, kmsg, ret);
 		}
 		if (ret == -ERESTARTSYS)
 			ret = -EINTR;
@@ -1500,8 +1505,7 @@ int io_send_zc(struct io_kiocb *req, unsigned int issue_flags)
 			zc->len -= ret;
 			zc->buf += ret;
 			zc->done_io += ret;
-			req->flags |= REQ_F_BL_NO_RECYCLE;
-			return -EAGAIN;
+			return io_net_kbuf_recyle(req, kmsg, ret);
 		}
 		if (ret == -ERESTARTSYS)
 			ret = -EINTR;
@@ -1571,8 +1575,7 @@ int io_sendmsg_zc(struct io_kiocb *req, unsigned int issue_flags)
 
 		if (ret > 0 && io_net_retry(sock, flags)) {
 			sr->done_io += ret;
-			req->flags |= REQ_F_BL_NO_RECYCLE;
-			return -EAGAIN;
+			return io_net_kbuf_recyle(req, kmsg, ret);
 		}
 		if (ret == -ERESTARTSYS)
 			ret = -EINTR;