From 95d1c8e5f801e959a89181a2548a3efa60a1a6ce Mon Sep 17 00:00:00 2001
From: Jiufei Xue <jiufei.xue@linux.alibaba.com>
Date: Wed, 2 Sep 2020 17:59:39 +0800
Subject: [PATCH] io_uring: set table->files[i] to NULL when
io_sqe_file_register failed
While io_sqe_file_register() failed in __io_sqe_files_update(),
table->files[i] still point to the original file which may freed
soon, and that will trigger use-after-free problems.
Cc: stable@vger.kernel.org
Fixes: f3bd9dae3708 ("io_uring: fix memleak in __io_sqe_files_update()")
Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/io_uring.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index a06b56289039..b1ccd7072d93 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7353,6 +7353,7 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
table->files[index] = file;
err = io_sqe_file_register(ctx, file, i);
if (err) {
+ table->files[index] = NULL;
fput(file);
break;
}