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drm/vc4: crtc: Switch to drmm_kzalloc
authorMaxime Ripard <maxime@cerno.tech>
Mon, 11 Jul 2022 17:38:51 +0000 (19:38 +0200)
committerMaxime Ripard <maxime@cerno.tech>
Wed, 13 Jul 2022 08:46:07 +0000 (10:46 +0200)
commit7cc4214c27cf8d664358db402a179bf6ab2db862
tree866d2f3bbc1e1c9b3721e28f241c858a0868205e
parent6bad4774157c9df64e1b04a8d893e282e16a9c23
drm/vc4: crtc: Switch to drmm_kzalloc

Our internal structure that stores the DRM entities structure is allocated
through a device-managed kzalloc.

This means that this will eventually be freed whenever the device is
removed. In our case, the most likely source of removal is that the main
device is going to be unbound, and component_unbind_all() is being run.

However, it occurs while the DRM device is still registered, which will
create dangling pointers, eventually resulting in use-after-free.

Switch to a DRM-managed allocation to keep our structure until the DRM
driver doesn't need it anymore.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220711173939.1132294-22-maxime@cerno.tech
drivers/gpu/drm/vc4/vc4_crtc.c