Commit c09cc2c3 authored Jun 10, 2020 by Dan Carpenter Committed by Michael S. Tsirkin Jun 22, 2020

vhost_vdpa: Fix potential underflow in vhost_vdpa_mmap()



The "vma->vm_pgoff" variable is an unsigned long so if it's larger than
INT_MAX then "index" can be negative leading to an underflow.  Fix this
by changing the type of "index" to "unsigned long".

Fixes: ddd89d0a ("vhost_vdpa: support doorbell mapping via mmap")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20200610085852.GB5439@mwanda


Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

parent 24eae8eb

drivers/vhost/vdpa.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -818,7 +818,7 @@ static int vhost_vdpa_mmap(struct file file, struct vm_area_struct vma)
		struct vdpa_device *vdpa = v->vdpa;
		const struct vdpa_config_ops *ops = vdpa->config;
		struct vdpa_notification_area notify;
		int index = vma->vm_pgoff;
		unsigned long index = vma->vm_pgoff;

		if (vma->vm_end - vma->vm_start != PAGE_SIZE)
		return -EINVAL;

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