Bjoern A. Zeeb
2008-Oct-25 22:05 UTC
CVE-2008-3831 / svn commit: r184263 - head/sys/dev/drm (fwd)
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, the commit referenced below fixes a problem arosen from an insufficient (missing) privilege check. If you are running a HEAD kernel from Aug 23 2008 (r182080) or later with drm/i915drm you want to update your kernel. The problem is only present in HEAD thus there will be no security advisory. Regards, Bjoern A. Zeeb FreeBSD Security Team - -- Bjoern A. Zeeb Stop bit received. Insert coin for new game. - ---------- Forwarded message ---------- Date: Sat, 25 Oct 2008 16:29:28 +0000 (UTC) From: Robert Noland <rnoland@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r184263 - head/sys/dev/drm Author: rnoland Date: Sat Oct 25 16:29:28 2008 New Revision: 184263 URL: http://svn.freebsd.org/changeset/base/184263 Log: 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. Approved by: bz (secteam) Obtained from: Intel drm repo Security: CVE-2008-3831 Modified: head/sys/dev/drm/i915_dma.c Modified: head/sys/dev/drm/i915_dma.c =============================================================================- --- head/sys/dev/drm/i915_dma.c Sat Oct 25 14:01:29 2008 (r184262) +++ head/sys/dev/drm/i915_dma.c Sat Oct 25 16:29:28 2008 (r184263) @@ -1228,7 +1228,7 @@ struct drm_ioctl_desc i915_ioctls[] = { 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_MMIO, i915_mmio, 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), #ifdef I915_HAVE_BUFFER DRM_IOCTL_DEF(DRM_I915_EXECBUFFER, i915_execbuffer, DRM_AUTH), #endif -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.2 (FreeBSD) iD8DBQFJA5MKK1i4+DzPGEIRAp0NAJ9cGyIwyTLp4hYvbwYMll7cROkmKQCghNvb sy2LhCFWcEzfad7oEP1qU4M=RXrx -----END PGP SIGNATURE-----