From: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx> [ 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> --- drivers/vdpa/vdpa_user/vduse_dev.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c index 35dceee3ed56..31017ebc4d7c 100644 --- a/drivers/vdpa/vdpa_user/vduse_dev.c +++ b/drivers/vdpa/vdpa_user/vduse_dev.c @@ -1440,6 +1440,9 @@ 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; -- 2.35.1
