On Wed, Jul 21, 2010 at 1:00 AM, Alex Deucher <alexdeucher at gmail.com> wrote: > On Tue, Jul 20, 2010 at 4:13 PM, Alexander Y. Fomichev > <git.user at gmail.com> wrote: >> On Tue, Jul 20, 2010 at 9:37 PM, Alex Deucher <alexdeucher at gmail.com> >> wrote: >>> On Mon, Jul 19, 2010 at 5:42 PM, Alexander Y. Fomichev >>> <git.user at 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. > Alex > >> >> -- >> Best regards. >> ? ? ?? Alexander Y. Fomichev <git.user at gmail.com> >> > -- Best regards. ? ? ?? Alexander Y. Fomichev <git.user at gmail.com>
