From: Christoph Hellwig <hch@lst.de>
Date: Wed, 18 May 2022 08:40:05 +0000 (+0200)
Subject: io_uring: use rcu_dereference in io_close
X-Git-Tag: baikal/aarch64/sdk6.1~4026^2~4
X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=11711f4167c7423e559fe1710f6df126462d8285;p=kernel.git

io_uring: use rcu_dereference in io_close

Accessing the file table needs a rcu_dereference_protected().

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220518084005.3255380-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/fs/io_uring.c b/fs/io_uring.c
index e24eb20f7e307..7b27afdab0e65 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -5372,7 +5372,8 @@ static int io_close(struct io_kiocb *req, unsigned int issue_flags)
 		spin_unlock(&files->file_lock);
 		goto err;
 	}
-	file = fdt->fd[close->fd];
+	file = rcu_dereference_protected(fdt->fd[close->fd],
+			lockdep_is_held(&files->file_lock));
 	if (!file || file->f_op == &io_uring_fops) {
 		spin_unlock(&files->file_lock);
 		file = NULL;