vduse: check that offset is within bounds in get_config()

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commit dc1db0060c upstream.

This condition checks "len" but it does not check "offset" and that
could result in an out of bounds read if "offset > dev->config_size".
The problem is that since both variables are unsigned the
"dev->config_size - offset" subtraction would result in a very high
unsigned value.

I think these checks might not be necessary because "len" and "offset"
are supposed to already have been validated using the
vhost_vdpa_config_validate() function.  But I do not know the code
perfectly, and I like to be safe.

Fixes: c8a6153b6c ("vduse: Introduce VDUSE - vDPA Device in Userspace")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20211208150956.GA29160@kili
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

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Dan Carpenter 2021-12-08 18:09:56 +03:00 • committed by Greg Kroah-Hartman

parent e6c67560b4

commit ebbbc5fea3

1 changed files with 2 additions and 1 deletions

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drivers/vdpa/vdpa_user/vduse_dev.c

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