Date: Mon, 31 Aug 2009 10:31:36 GMT From: Patroklos Argyroudis <argp@census-labs.com> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/138383: NULL pointer dereference in mach64_dma_vertex() in file sys/dev/drm/mach64_state.c Message-ID: <200908311031.n7VAVaHj076047@www.freebsd.org> Resent-Message-ID: <200908311040.n7VAe4hU041026@freefall.freebsd.org>
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>Number: 138383
>Category: kern
>Synopsis: NULL pointer dereference in mach64_dma_vertex() in file sys/dev/drm/mach64_state.c
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Mon Aug 31 10:40:03 UTC 2009
>Closed-Date:
>Last-Modified:
>Originator: Patroklos Argyroudis
>Release: 8.0-CURRENT
>Organization:
census, inc
>Environment:
N/A
>Description:
There is a NULL pointer dereference in mach64_dma_vertex() line 829 in file sys/dev/drm/mach64_state.c. The check against NULL in line 834 should happen before the dereference of dev_priv.
>How-To-Repeat:
N/A
>Fix:
Patch attached.
Patch attached with submission follows:
--- ./sys/dev/drm/mach64_state.c.orig 2009-08-28 15:42:13.000000000 +0300
+++ ./sys/dev/drm/mach64_state.c 2009-08-28 15:55:17.000000000 +0300
@@ -826,7 +826,7 @@
struct drm_file *file_priv)
{
drm_mach64_private_t *dev_priv = dev->dev_private;
- drm_mach64_sarea_t *sarea_priv = dev_priv->sarea_priv;
+ drm_mach64_sarea_t *sarea_priv;
drm_mach64_vertex_t *vertex = data;
LOCK_TEST_WITH_RETURN(dev, file_priv);
@@ -836,6 +836,8 @@
return -EINVAL;
}
+ sarea_priv = dev_priv->sarea_priv;
+
DRM_DEBUG("pid=%d buf=%p used=%lu discard=%d\n",
DRM_CURRENTPID,
vertex->buf, vertex->used, vertex->discard);
>Release-Note:
>Audit-Trail:
>Unformatted:
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