From d8a3ba9c143bf89c032deced8a686ffa53b46098 Mon Sep 17 00:00:00 2001
From: Dylan Yudaken <dylany@fb.com>
Date: Tue, 12 Apr 2022 09:30:40 -0700
Subject: [PATCH] io_uring: verify that resv2 is 0 in io_uring_rsrc_update2
Git-commit: d8a3ba9c143bf89c032deced8a686ffa53b46098
Patch-mainline: v5.18-rc3
References: bsc#1205205

Verify that the user does not pass in anything but 0 for this field.

Fixes: 992da01aa932 ("io_uring: change registration/upd/rsrc tagging ABI")
Signed-off-by: Dylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/20220412163042.2788062-3-dylany@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
---
 fs/io_uring.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 58bfa71fe3b6..e899192ffb77 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6839,6 +6839,7 @@ static int io_files_update(struct io_kiocb *req, unsigned int issue_flags)
 	up.nr = 0;
 	up.tags = 0;
 	up.resv = 0;
+	up.resv2 = 0;
 
 	io_ring_submit_lock(ctx, needs_lock);
 	ret = __io_register_rsrc_update(ctx, IORING_RSRC_FILE,
@@ -11423,7 +11424,7 @@ static int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg,
 	memset(&up, 0, sizeof(up));
 	if (copy_from_user(&up, arg, sizeof(struct io_uring_rsrc_update)))
 		return -EFAULT;
-	if (up.resv)
+	if (up.resv || up.resv2)
 		return -EINVAL;
 	return __io_register_rsrc_update(ctx, IORING_RSRC_FILE, &up, nr_args);
 }
@@ -11437,7 +11438,7 @@ static int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
 		return -EINVAL;
 	if (copy_from_user(&up, arg, sizeof(up)))
 		return -EFAULT;
-	if (!up.nr || up.resv)
+	if (!up.nr || up.resv || up.resv2)
 		return -EINVAL;
 	return __io_register_rsrc_update(ctx, type, &up, up.nr);
 }
-- 
2.35.3