Merge tag 'io_uring-6.12-20241004' of git://git.kernel.dk/linux

Pull io_uring fixes from Jens Axboe:

 - Fix an error path memory leak, if one part fails to allocate.
   Obviously not something that'll generally hit without error
   injection.

 - Fix an io_req_flags_t cast to make sparse happier.

 - Improve the recv multishot termination. Not a bug now, but could be
   one in the future. This makes it do the same thing that recvmsg does
   in terms of when to terminate a request or not.

* tag 'io_uring-6.12-20241004' of git://git.kernel.dk/linux:
  io_uring/net: harden multishot termination case for recv
  io_uring: fix casts to io_req_flags_t
  io_uring: fix memory leak when cache init fail

Author: torvalds

io_uring/io_uring.c

@@ -321,7 +321,7 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
 			    sizeof(struct io_kiocb));
 	ret |= io_futex_cache_init(ctx);
 	if (ret)
-		goto err;
+		goto free_ref;
 	init_completion(&ctx->ref_comp);
 	xa_init_flags(&ctx->personalities, XA_FLAGS_ALLOC1);
 	mutex_init(&ctx->uring_lock);
@@ -349,6 +349,9 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
 	io_napi_init(ctx);
 
 	return ctx;
+
+free_ref:
+	percpu_ref_exit(&ctx->refs);
 err:
 	io_alloc_cache_free(&ctx->rsrc_node_cache, kfree);
 	io_alloc_cache_free(&ctx->apoll_cache, kfree);
@@ -2038,7 +2041,7 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
 	req->opcode = opcode = READ_ONCE(sqe->opcode);
 	/* same numerical values with corresponding REQ_F_*, safe to copy */
 	sqe_flags = READ_ONCE(sqe->flags);
-	req->flags = (io_req_flags_t) sqe_flags;
+	req->flags = (__force io_req_flags_t) sqe_flags;
 	req->cqe.user_data = READ_ONCE(sqe->user_data);
 	req->file = NULL;
 	req->rsrc_node = NULL;

io_uring/net.c

@@ -1133,6 +1133,7 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags)
 	int ret, min_ret = 0;
 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
 	size_t len = sr->len;
+	bool mshot_finished;
 
 	if (!(req->flags & REQ_F_POLLED) &&
 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
@@ -1187,14 +1188,15 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags)
 		req_set_fail(req);
 	}
 
+	mshot_finished = ret <= 0;
 	if (ret > 0)
 		ret += sr->done_io;
 	else if (sr->done_io)
 		ret = sr->done_io;
 	else
 		io_kbuf_recycle(req, issue_flags);
 
-	if (!io_recv_finish(req, &ret, kmsg, ret <= 0, issue_flags))
+	if (!io_recv_finish(req, &ret, kmsg, mshot_finished, issue_flags))
 		goto retry_multishot;
 
 	return ret;