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From: Boris Brezillon <boris.brezillon@collabora.com>
To: Steven Price <steven.price@arm.com>,
	Liviu Dudau <liviu.dudau@arm.com>,
	 Boris Brezillon <boris.brezillon@collabora.com>,
	 Dmitry Osipenko <dmitry.osipenko@collabora.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	 Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	 David Airlie <airlied@gmail.com>,
	Simona Vetter <simona@ffwll.ch>,  Akash Goel <akash.goel@arm.com>,
	Chia-I Wu <olvaffe@gmail.com>,
	 Rob Clark <robin.clark@oss.qualcomm.com>,
	 Dmitry Baryshkov <lumag@kernel.org>,
	 Abhinav Kumar <abhinav.kumar@linux.dev>,
	 Jessica Zhang <jesszhan0024@gmail.com>,
	Sean Paul <sean@poorly.run>,
	 Marijn Suijten <marijn.suijten@somainline.org>,
	 linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org,
	 dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: [PATCH 0/3] drm/panthor: Fix a race in the shrinker logic
Date: Wed, 06 May 2026 14:16:25 +0200	[thread overview]
Message-ID: <20260506-panthor-shrinker-fixes-v1-0-e7721526de96@collabora.com> (raw)

As reported by Chia-I [1], a race exists between drm_gem_lru_remove()
and drm_gem_lru_scan(), causing a UAF on a stack-allocated object.

This first patch fixes the problem at the panthor level by making
sure we never use drm_gem_lru_remove(). The second one fixes an
undetected race between drm_gem_lru_scan() and
drm_gem_object_release(), and the last one kills drm_gem_lru_remove()
so no one else relying on the drm_gem_lru infra gets bitten by this
race again.

Adding the MSM maintainers to the loop, since it's the only other
driver relying on drm_gem_lru.

[1]https://gitlab.freedesktop.org/panfrost/linux/-/work_items/86

---
Boris Brezillon (3):
      drm/panthor: Don't use the racy drm_gem_lru_remove() helper
      drm/gem: Fix a race between drm_gem_lru_scan() and drm_gem_object_release()
      drm/gem: Stop exposing the racy/unsafe drm_gem_lru_remove() helper

 drivers/gpu/drm/drm_gem.c                | 63 ++++++++++++++------------------
 drivers/gpu/drm/panthor/panthor_device.h | 10 +++++
 drivers/gpu/drm/panthor/panthor_gem.c    |  5 ++-
 include/drm/drm_gem.h                    |  1 -
 4 files changed, 41 insertions(+), 38 deletions(-)
---
base-commit: 57f68ed1f08cd10f51a9091645fd5dfcc369a885
change-id: 20260506-panthor-shrinker-fixes-58c1f45cfc41

Best regards,
-- 
Boris Brezillon <boris.brezillon@collabora.com>


             reply	other threads:[~2026-05-06 12:16 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-06 12:16 Boris Brezillon [this message]
2026-05-06 12:16 ` [PATCH 1/3] drm/panthor: Don't use the racy drm_gem_lru_remove() helper Boris Brezillon
2026-05-06 15:40   ` Steven Price
2026-05-06 16:25     ` Boris Brezillon
2026-05-06 12:16 ` [PATCH 2/3] drm/gem: Fix a race between drm_gem_lru_scan() and drm_gem_object_release() Boris Brezillon
2026-05-06 13:21   ` Rob Clark
2026-05-06 14:33     ` Boris Brezillon
2026-05-06 12:16 ` [PATCH 3/3] drm/gem: Stop exposing the racy/unsafe drm_gem_lru_remove() helper Boris Brezillon
2026-05-06 15:40   ` Steven Price

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