This is a note to let you know that I've just added the patch titled
vduse: prevent uninitialized memory accesses
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
vduse-prevent-uninitialized-memory-accesses.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 46f8a29272e51b6df7393d58fc5cb8967397ef2b Mon Sep 17 00:00:00 2001
From: Maxime Coquelin <maxime.coquelin@xxxxxxxxxx>
Date: Wed, 31 Aug 2022 17:49:23 +0200
Subject: vduse: prevent uninitialized memory accesses
From: Maxime Coquelin <maxime.coquelin@xxxxxxxxxx>
commit 46f8a29272e51b6df7393d58fc5cb8967397ef2b upstream.
If the VDUSE application provides a smaller config space
than the driver expects, the driver may use uninitialized
memory from the stack.
This patch prevents it by initializing the buffer passed by
the driver to store the config value.
This fix addresses CVE-2022-2308.
Cc: stable@xxxxxxxxxxxxxxx # v5.15+
Fixes: c8a6153b6c59 ("vduse: Introduce VDUSE - vDPA Device in Userspace")
Reviewed-by: Xie Yongji <xieyongji@xxxxxxxxxxxxx>
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Signed-off-by: Maxime Coquelin <maxime.coquelin@xxxxxxxxxx>
Message-Id: <20220831154923.97809-1-maxime.coquelin@xxxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Reviewed-by: Chaitanya Kulkarni <kch@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/vdpa/vdpa_user/vduse_dev.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -655,10 +655,15 @@ static void vduse_vdpa_get_config(struct
{
struct vduse_dev *dev = vdpa_to_vduse(vdpa);
- if (offset > dev->config_size ||
- len > dev->config_size - offset)
+ /* Initialize the buffer in case of partial copy. */
+ memset(buf, 0, len);
+
+ if (offset > dev->config_size)
return;
+ if (len > dev->config_size - offset)
+ len = dev->config_size - offset;
+
memcpy(buf, dev->config + offset, len);
}
Patches currently in stable-queue which might be from maxime.coquelin@xxxxxxxxxx are
queue-5.15/vduse-prevent-uninitialized-memory-accesses.patch
