Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932666Ab0GTVBq (ORCPT ); Tue, 20 Jul 2010 17:01:46 -0400 Received: from mail-iw0-f174.google.com ([209.85.214.174]:65077 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761626Ab0GTVA2 convert rfc822-to-8bit (ORCPT ); Tue, 20 Jul 2010 17:00:28 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=v5WaSM+dGC2bZLyQ87qoYglVt74gRK6Rt8R3aHXy/ScaamTfLdv97XOoAvDk/G61uN bh2fO7ZXVv5K9J5HnFQq0l5/oz/9tTdcuwkS75Ms+06rYkS5ET32Na81jBymbSzp5+Fr xKAg1VcmwkjWae1kZluxaJNp9dzzkUVTsw8rA= MIME-Version: 1.0 In-Reply-To: References: <20100720014251.46b91cdd@mad-cat.localdomain> Date: Tue, 20 Jul 2010 17:00:27 -0400 Message-ID: Subject: Re: drivers/gpu/drm/radeon/r600_blit.c: fix possible NULL pointer derefernce From: Alex Deucher To: "Alexander Y. Fomichev" Cc: Dave Airlie , Robert Noland , Matt Turner , Jerome Glisse , akpm@linux-foundation.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2364 Lines: 71 On Tue, Jul 20, 2010 at 4:13 PM, Alexander Y. Fomichev wrote: > On Tue, Jul 20, 2010 at 9:37 PM, Alex Deucher wrote: >> On Mon, Jul 19, 2010 at 5:42 PM, Alexander Y. Fomichev >> wrote: >>> This patch fix possible NULL pointer dereference when >>> r600_prepare_blit_copy tries to fill dev_priv->blit_vb->file_priv >>> without check of dev_priv->blit_vb. dev_priv->blit_vb should be >>> filled by r600_nomm_get_vb but latest can fail with EAGAIN. >>> Addresses: https://bugzilla.kernel.org/show_bug.cgi?id=16375 >>> >>> --- >>> ?drivers/gpu/drm/radeon/r600_blit.c | ? ?2 ++ >>> ?1 files changed, 2 insertions(+), 0 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/radeon/r600_blit.c b/drivers/gpu/drm/radeon/r600_blit.c >>> index f4fb88e..0df4a2b 100644 >>> --- a/drivers/gpu/drm/radeon/r600_blit.c >>> +++ b/drivers/gpu/drm/radeon/r600_blit.c >>> @@ -541,6 +541,8 @@ r600_prepare_blit_copy(struct drm_device *dev, struct drm_file *file_priv) >>> ? ? ? ?DRM_DEBUG("\n"); >>> >>> ? ? ? ?r600_nomm_get_vb(dev); >>> + ? ? ? if (!dev_priv->blit_vb) >>> + ? ? ? ? ? ? ? return; >> >> r600_prepare_blit_copy returns an int so something like this would be better: >> --- a/drivers/gpu/drm/radeon/r600_blit.c >> +++ b/drivers/gpu/drm/radeon/r600_blit.c >> @@ -539,8 +539,10 @@ r600_prepare_blit_copy(struct drm_device *dev, >> struct drm_file *file_priv) >> ?{ >> ? ? ? ?drm_radeon_private_t *dev_priv = dev->dev_private; >> ? ? ? ?DRM_DEBUG("\n"); >> + ? ? ? int ret = r600_nomm_get_vb(dev); >> >> - ? ? ? r600_nomm_get_vb(dev); >> + ? ? ? if (ret) >> + ? ? ? ? ? ? ? return ret; >> >> ? ? ? ?dev_priv->blit_vb->file_priv = file_priv; >> >> >> Alex >> >>> >>> ? ? ? ?dev_priv->blit_vb->file_priv = file_priv; >>> >>> -- >>> 1.7.1.1 >>> >> > > i haven't any preferneces, the only thing is - it would be logical > to have every check in common style, so other cases > (r600_blit_copy, r600_blit_swap) should be fixed, nop? Those are void functions so there's nothing to return. Alex > > -- > Best regards. > ? ? ?? Alexander Y. Fomichev > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/