This is a note to let you know that I've just added the patch titled
vduse: Validate vq_num in vduse_validate_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-validate-vq_num-in-vduse_validate_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.
commit 139b1ac76679309d5ac1fbb05c175b1b9e11ec20
Author: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx>
Date: Mon Nov 28 07:57:15 2022 -0800
vduse: Validate vq_num in vduse_validate_config()
[ Upstream commit 937c783aa3d8d77963ec91918d3298edb45b9161 ]
Add a limit to 'config->vq_num' which is user controlled data which
comes from an vduse_ioctl to prevent large memory allocations.
Micheal says - This limit is somewhat arbitrary.
However, currently virtio pci and ccw are limited to a 16 bit vq number.
While MMIO isn't it is also isn't used with lots of VQs due to
current lack of support for per-vq interrupts.
Thus, the 0xffff limit on number of VQs corresponding
to a 16-bit VQ number seems sufficient for now.
This is found using static analysis with smatch.
Suggested-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx>
Message-Id: <20221128155717.2579992-1-harshit.m.mogalapalli@xxxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index e7d2d5b7e125..3467c75f310a 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -1251,6 +1251,9 @@ static bool vduse_validate_config(struct vduse_dev_config *config)
if (config->config_size > PAGE_SIZE)
return false;
+ if (config->vq_num > 0xffff)
+ return false;
+
if (!device_is_allowed(config->device_id))
return false;
