From: Matthias Hopf Date: Fri, 17 Oct 2008 21:18:05 +0000 (+1000) Subject: drm/i915: fix ioremap of a user address for non-root (CVE-2008-3831) X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=4b40893918203ee1a1f6a114316c2a19c072e9bd;p=deliverable%2Flinux.git drm/i915: fix ioremap of a user address for non-root (CVE-2008-3831) Olaf Kirch noticed that the i915_set_status_page() function of the i915 kernel driver calls ioremap with an address offset that is supplied by userspace via ioctl. The function zeroes the mapped memory via memset and tells the hardware about the address. Turns out that access to that ioctl is not restricted to root so users could probably exploit that to do nasty things. We haven't tried to write actual exploit code though. It only affects the Intel G33 series and newer. Signed-off-by: Dave Airlie --- diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index 9b967bf3aa6a..db34780edbb2 100644 --- a/drivers/gpu/drm/i915/i915_dma.c +++ b/drivers/gpu/drm/i915/i915_dma.c @@ -940,7 +940,7 @@ struct drm_ioctl_desc i915_ioctls[] = { DRM_IOCTL_DEF(DRM_I915_SET_VBLANK_PIPE, i915_vblank_pipe_set, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY ), DRM_IOCTL_DEF(DRM_I915_GET_VBLANK_PIPE, i915_vblank_pipe_get, DRM_AUTH ), DRM_IOCTL_DEF(DRM_I915_VBLANK_SWAP, i915_vblank_swap, DRM_AUTH), - DRM_IOCTL_DEF(DRM_I915_HWS_ADDR, i915_set_status_page, DRM_AUTH), + DRM_IOCTL_DEF(DRM_I915_HWS_ADDR, i915_set_status_page, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), DRM_IOCTL_DEF(DRM_I915_GEM_INIT, i915_gem_init_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), DRM_IOCTL_DEF(DRM_I915_GEM_EXECBUFFER, i915_gem_execbuffer, DRM_AUTH), DRM_IOCTL_DEF(DRM_I915_GEM_PIN, i915_gem_pin_ioctl, DRM_AUTH|DRM_ROOT_ONLY),