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. Alex > > -- > Best regards. > ? ? ?? Alexander Y. Fomichev <git.user at gmail.com> >
