From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758951Ab3AQDRp (ORCPT ); Wed, 16 Jan 2013 22:17:45 -0500 Received: from ihemail1.lucent.com ([135.245.0.33]:57593 "EHLO ihemail1.lucent.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758366Ab3AQDRn (ORCPT ); Wed, 16 Jan 2013 22:17:43 -0500 X-Greylist: delayed 632 seconds by postgrey-1.27 at vger.kernel.org; Wed, 16 Jan 2013 22:17:43 EST Date: Wed, 16 Jan 2013 21:06:49 -0600 (CST) From: Ilija Hadzic X-X-Sender: ihadzic@umail To: Shuah Khan cc: airlied@linux.ie, deathsimple@vodafone.de, jglisse@redhat.com, airlied@redhat.com, "Deucher, Alexander" , Greg KH , LKML , dri-devel@lists.freedesktop.org, shuahkhan@gmail.com Subject: Re: [PATCH] drm/radeon: fix NULL pointer dereference in UMS mode in radeon_cs_parser_fini() In-Reply-To: <1358379788.7243.10.camel@lorien2> Message-ID: References: <1358379788.7243.10.camel@lorien2> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Actually, the code path affected by your patch is not executed in UMS mode at all. Notice that radeon_cs_parser_fini is only called from radeon_cs_ioctl which is a KMS-only ioctl (see radeon_kms.c). The equivalent of the fix you are trying to do is in a6b7e1a02b77ab8fe8775d20a88c53d8ba55482e (function patched by that one is the one used by legacy-CS ioctl), which you should go together with ff4bd0827764e10a428a9d39e6814c5478863f94 if you are backporting UMS fixes to 3.7. Both are needed to prevent kernel crashes in UMS mode. -- Ilija On Wed, 16 Jan 2013, Shuah Khan wrote: > Fix parser->rdev NULL pointer dereference in radeon_cs_parser_fini(). > While back-porting drm/radeon: fix NULL pointer dereference in UMS mode > patch (commit-id: ff4bd0827764e10a428a9d39e6814c5478863f94) to 3,7.y, noticed > another instance of NULL pointer dereference in radeon_cs_parser_fini() > function. > > Signed-off-by: Shuah Khan > CC: stable@vger.kernel.org 3.7 > --- > drivers/gpu/drm/radeon/radeon_cs.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c > index 469661f..d1c282c 100644 > --- a/drivers/gpu/drm/radeon/radeon_cs.c > +++ b/drivers/gpu/drm/radeon/radeon_cs.c > @@ -329,7 +329,7 @@ static void radeon_cs_parser_fini(struct radeon_cs_parser *parser, int error) > kfree(parser->relocs_ptr); > for (i = 0; i < parser->nchunks; i++) { > kfree(parser->chunks[i].kdata); > - if ((parser->rdev->flags & RADEON_IS_AGP)) { > + if (parser->rdev && (parser->rdev->flags & RADEON_IS_AGP)) { > kfree(parser->chunks[i].kpage[0]); > kfree(parser->chunks[i].kpage[1]); > } > -- > 1.7.9.5 > > > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel >