Messages in this thread | | | Date | Wed, 2 Nov 2022 10:15:56 +0100 | Subject | Re: [PATCH v2 2/2] drm/client: Prevent NULL dereference in drm_client_buffer_delete() | From | Christian König <> |
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Am 30.10.22 um 16:44 schrieb Dmitry Osipenko: > The drm_gem_vunmap() will crash with a NULL dereference if the passed > object pointer is NULL. It wasn't a problem before we added the locking > support to drm_gem_vunmap function because the mapping argument was always > NULL together with the object. Make drm_client_buffer_delete() to check > whether GEM is NULL before trying to unmap the GEM, it will happen on > framebuffer creation error. > > Reported-by: Dan Carpenter <dan.carpenter@oracle.com> > Link: https://lore.kernel.org/dri-devel/Y1kFEGxT8MVlf32V@kili/ > Fixes: 79e2cf2e7a19 ("drm/gem: Take reservation lock for vmap/vunmap operations") > Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
> --- > drivers/gpu/drm/drm_client.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c > index 38e1be991caa..fd67efe37c63 100644 > --- a/drivers/gpu/drm/drm_client.c > +++ b/drivers/gpu/drm/drm_client.c > @@ -235,10 +235,10 @@ static void drm_client_buffer_delete(struct drm_client_buffer *buffer) > { > struct drm_device *dev = buffer->client->dev; > > - drm_gem_vunmap_unlocked(buffer->gem, &buffer->map); > - > - if (buffer->gem) > + if (buffer->gem) { > + drm_gem_vunmap_unlocked(buffer->gem, &buffer->map); > drm_gem_object_put(buffer->gem); > + } > > if (buffer->handle) > drm_mode_destroy_dumb(dev, buffer->handle, buffer->client->file);
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