>From b04cf18255722339e4d1f51389bd842991322b73 Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@gmail.com>
Date: Mon, 13 Sep 2021 09:35:35 -0600
Subject: [PATCH 1/5] io_uring: limit fixed table size by RLIMIT_NOFILE

Limit the number of files in io_uring fixed tables by RLIMIT_NOFILE,
that's the first and the simpliest restriction that we should impose.

Cc: stable@vger.kernel.org
Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b2756c340aed7d6c0b302c26dab50c6c5907f4ce.1629451684.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/io_uring.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 2009d1cda606..0db463599b00 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7579,6 +7579,8 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 		return -EINVAL;
 	if (nr_args > IORING_MAX_FIXED_FILES)
 		return -EMFILE;
+	if (nr_args > rlimit(RLIMIT_NOFILE))
+		return -EMFILE;
 
 	file_data = kzalloc(sizeof(*ctx->file_data), GFP_KERNEL);
 	if (!file_data)
-- 
2.33.0

