On Thu, Apr 04, 2024 at 11:33:25PM +0300, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrj...@linux.intel.com>
>
> The modes[] array contains pointers to modes on the connectors'
> mode lists, which are protected by dev->mode_config.mutex.
> Thus we need to extend modes[] the same protection or by the
> time we use it the elements may already be pointing to
> freed/reused memory.
>
> Cc: sta...@vger.kernel.org
> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/10583
> Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com>
Reviewed-by: Dmitry Baryshkov <dmitry.barysh...@linaro.org>
I tried looking for the proper Fixes tag, but it looks like it might be
something like 386516744ba4 ("drm/fb: fix fbdev object model + cleanup
properly.")
> ---
> drivers/gpu/drm/drm_client_modeset.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_client_modeset.c
> b/drivers/gpu/drm/drm_client_modeset.c
> index 871e4e2129d6..0683a129b362 100644
> --- a/drivers/gpu/drm/drm_client_modeset.c
> +++ b/drivers/gpu/drm/drm_client_modeset.c
> @@ -777,6 +777,7 @@ int drm_client_modeset_probe(struct drm_client_dev
> *client, unsigned int width,
> unsigned int total_modes_count = 0;
> struct drm_client_offset *offsets;
> unsigned int connector_count = 0;
> + /* points to modes protected by mode_config.mutex */
> struct drm_display_mode **modes;
> struct drm_crtc **crtcs;
> int i, ret = 0;
> @@ -845,7 +846,6 @@ int drm_client_modeset_probe(struct drm_client_dev
> *client, unsigned int width,
> drm_client_pick_crtcs(client, connectors, connector_count,
> crtcs, modes, 0, width, height);
> }
> - mutex_unlock(&dev->mode_config.mutex);
>
> drm_client_modeset_release(client);
>
> @@ -875,6 +875,7 @@ int drm_client_modeset_probe(struct drm_client_dev
> *client, unsigned int width,
> modeset->y = offset->y;
> }
> }
> + mutex_unlock(&dev->mode_config.mutex);
>
> mutex_unlock(&client->modeset_mutex);
> out:
> --
> 2.43.2
>
--
With best wishes
Dmitry
