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Date: Tue, 27 Feb 2024 18:21:46 +0300
From: Dan Carpenter <dan.carpenter@linaro.org>
To: Cindy Lu <lulu@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>, Jason Wang <jasowang@redhat.com>,
	Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
	Xie Yongji <xieyongji@bytedance.com>,
	Maxime Coquelin <maxime.coquelin@redhat.com>,
	Christian Brauner <brauner@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	virtualization@lists.linux.dev, linux-kernel@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: [PATCH] vduse: Fix off by one in vduse_dev_mmap()
Message-ID: <e26476e0-68ae-412d-a5d9-4996bc30d038@moroto.mountain>
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The dev->vqs[] array has "dev->vq_num" elements.  It's allocated in
vduse_dev_init_vqs().  Thus, this > comparison needs to be >= to avoid
reading one element beyond the end of the array.

Fixes: 316ecd1346b0 ("vduse: Add file operation for mmap")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/vdpa/vdpa_user/vduse_dev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index b7a1fb88c506..9150c8281953 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -1532,7 +1532,7 @@ static int vduse_dev_mmap(struct file *file, struct vm_area_struct *vma)
 	if ((vma->vm_flags & VM_SHARED) == 0)
 		return -EINVAL;
 
-	if (index > dev->vq_num)
+	if (index >= dev->vq_num)
 		return -EINVAL;
 
 	vq = dev->vqs[index];
-- 
2.43.0