Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761486Ab0GTUNp (ORCPT ); Tue, 20 Jul 2010 16:13:45 -0400 Received: from mail-bw0-f46.google.com ([209.85.214.46]:51568 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758581Ab0GTUNo convert rfc822-to-8bit (ORCPT ); Tue, 20 Jul 2010 16:13:44 -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=EMnkEuWn4/9Myvi5sKlx2mmSgL48NS+NNYjzEBh6ULOMD0pkGwrF+mK2V9aMGoP5Ak BYMFBKDOeU/CIXwP6cLAWk0a8xBSpNa/txYZRGXs2WMYjJl3WDC1ijsB3gNXrmT1HiM5 aahI9REmTB/Gvy1Nbs82eVkXycC4Zqag6Ue0I= MIME-Version: 1.0 In-Reply-To: References: <20100720014251.46b91cdd@mad-cat.localdomain> Date: Wed, 21 Jul 2010 00:13:42 +0400 Message-ID: Subject: Re: drivers/gpu/drm/radeon/r600_blit.c: fix possible NULL pointer derefernce From: "Alexander Y. Fomichev" To: Alex Deucher 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: 2152 Lines: 63 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? -- 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/