From 54e4b4720e7eda31b4e3c72a09d0bcda9dd3482c Mon Sep 17 00:00:00 2001 From: Matthias Hopf Date: Sat, 18 Oct 2008 07:18:05 +1000 Subject: [PATCH] drm/i915: fix ioremap of a user address for non-root (CVE-2008-3831) commit 4b40893918203ee1a1f6a114316c2a19c072e9bd upstream 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 Signed-off-by: Greg Kroah-Hartman --- drivers/char/drm/i915_dma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/drm/i915_dma.c b/drivers/char/drm/i915_dma.c index a043bb12301ac..ed2a83f9bcedc 100644 --- a/drivers/char/drm/i915_dma.c +++ b/drivers/char/drm/i915_dma.c @@ -836,7 +836,7 @@ 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), }; int i915_max_ioctl = DRM_ARRAY_SIZE(i915_ioctls); -- 2.47.2