This is a note to let you know that I've just added the patch titled vduse: check that offset is within bounds in get_config() 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-check-that-offset-is-within-bounds-in-get_config.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 dc1db0060c02d119fd4196924eff2d1129e9a442 Mon Sep 17 00:00:00 2001 From: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Date: Wed, 8 Dec 2021 18:09:56 +0300 Subject: vduse: check that offset is within bounds in get_config() From: Dan Carpenter <dan.carpenter@xxxxxxxxxx> commit dc1db0060c02d119fd4196924eff2d1129e9a442 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: c8a6153b6c59 ("vduse: Introduce VDUSE - vDPA Device in Userspace") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Link: https://lore.kernel.org/r/20211208150956.GA29160@kili Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/vdpa/vdpa_user/vduse_dev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/vdpa/vdpa_user/vduse_dev.c +++ b/drivers/vdpa/vdpa_user/vduse_dev.c @@ -655,7 +655,8 @@ static void vduse_vdpa_get_config(struct { struct vduse_dev *dev = vdpa_to_vduse(vdpa); - if (len > dev->config_size - offset) + if (offset > dev->config_size || + len > dev->config_size - offset) return; memcpy(buf, dev->config + offset, len); Patches currently in stable-queue which might be from dan.carpenter@xxxxxxxxxx are queue-5.15/vduse-fix-memory-corruption-in-vduse_dev_ioctl.patch queue-5.15/vduse-check-that-offset-is-within-bounds-in-get_config.patch queue-5.15/vdpa-check-that-offsets-are-within-bounds.patch