drivers/gpu/drm/radeon/r600_blit.c: fix possible NULL pointer derefernce
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From: Alexander Y. Fomichev on 21 Jul 2010 03:10 On Wed, Jul 21, 2010 at 1:29 AM, Alex Deucher <alexdeucher(a)gmail.com> wrote: > On Tue, Jul 20, 2010 at 5:07 PM, Alexander Y. Fomichev > <git.user(a)gmail.com> wrote: >> On Wed, Jul 21, 2010 at 1:00 AM, Alex Deucher <alexdeucher(a)gmail.com> wrote: >>> On Tue, Jul 20, 2010 at 4:13 PM, Alexander Y. Fomichev >>> <git.user(a)gmail.com> wrote: >>>> On Tue, Jul 20, 2010 at 9:37 PM, Alex Deucher <alexdeucher(a)gmail.com> wrote: >>>>> On Mon, Jul 19, 2010 at 5:42 PM, Alexander Y. Fomichev >>>>> <git.user(a)gmail.com> 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. >> >> i mean both of them call r600_nomm_get_vb and both of them >> check if (!dev_priv->blit_vb), not return �value.I mean would be >> logical to check it the same way everytime r600_nomm_get_vb >> gets called. > > yeah, either way. �You just need to return an error in r600_prepare_blit_copy. uh-huh, i've missed > Alex > >> >>> Alex >>> >>>> >>>> -- >>>> Best regards. >>>> � � �� Alexander Y. Fomichev <git.user(a)gmail.com> >>>> >>> >> >> >> >> -- >> Best regards. >> � � �� Alexander Y. Fomichev <git.user(a)gmail.com> >> > -- Best regards. � � �� Alexander Y. Fomichev <git.user(a)gmail.com> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |