On Tue, Feb 26, 2019 at 09:01:29PM +0000, Chris Wilson wrote: > Quoting Eric Biggers (2019-02-26 20:47:26) > > From: Eric Biggers <ebigg...@google.com> > > > > If drm_gem_handle_create() fails in vgem_gem_create(), then the > > drm_vgem_gem_object is freed twice: once when the reference is dropped > > by drm_gem_object_put_unlocked(), and again by __vgem_gem_destroy(). > > > > This was hit by syzkaller using fault injection. > > > > Fix it by skipping the second free. > > > > Reported-by: syzbot+e73f2fb5ed5a5df36...@syzkaller.appspotmail.com > > Fixes: 5ba6c9ff961a ("drm/vgem: Fix mmaping") > > That's the wrong fixes line, it's > Fixes: af33a9190d02 ("drm/vgem: Enable dmabuf import interfaces") > Cc: Chris Wilson <ch...@chris-wilson.co.uk> > Cc: Laura Abbott <labb...@redhat.com> > Cc: Daniel Vetter <daniel.vet...@ffwll.ch> > > Sadly I reviewed it so I'm still culpable, but the fix is correct as the > put purposely frees it on error. >
You're right; I misread the code at that commit. I'll resend with the correct tags. > > Cc: sta...@vger.kernel.org > > Signed-off-by: Eric Biggers <ebigg...@google.com> > > > --- > > drivers/gpu/drm/vgem/vgem_drv.c | 8 +++----- > > 1 file changed, 3 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/gpu/drm/vgem/vgem_drv.c > > b/drivers/gpu/drm/vgem/vgem_drv.c > > index 5930facd6d2d8..70646d9da1596 100644 > > --- a/drivers/gpu/drm/vgem/vgem_drv.c > > +++ b/drivers/gpu/drm/vgem/vgem_drv.c > > @@ -189,15 +189,13 @@ static struct drm_gem_object *vgem_gem_create(struct > > drm_device *dev, > > return ERR_CAST(obj); > > > > ret = drm_gem_handle_create(file, &obj->base, handle); > > + > > drm_gem_object_put_unlocked(&obj->base); > > + > > The pattern in the other GEM drivers is not to have these extra > newlines. > > Reviewed-by: Chris Wilson <ch...@chris-wilson.co.uk> > > > if (ret) > > - goto err; > > + return ERR_PTR(ret); > > > > return &obj->base; > > - > > -err: > > - __vgem_gem_destroy(obj); > > - return ERR_PTR(ret); > > } > > > > static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device > > *dev, > > -- > > 2.21.0.rc2.261.ga7da99ff1b-goog > > _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel