[PATCH] io_uring: set table->files[i] to NULL when io_sqe_file_register failed

[Jiufei Xue <jiufei.xue@xxxxxxxxxxxxxxxxx>]

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.

Signed-off-by: Jiufei Xue <jiufei.xue@xxxxxxxxxxxxxxxxx>
---
 fs/io_uring.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index ce69bd9..0092418 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;
 			}
-- 
1.8.3.1