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Dmitry Baryshkov 93c125e4ea drm/msm: don't tear down KMS twice when KMS init fails
When priv->kms_init() (mdp4_kms_init() / mdp5_kms_init()) fails partway
through, both display drivers already tear their KMS state down via
mdp4_destroy() / mdp5_kms_destroy() before returning the error. The
common error path in msm_drm_init() then runs msm_drm_uninit() ->
msm_drm_kms_uninit(), which tries to destroy the very same KMS a second
time, which causes a use-after-free crash.

Bring MDP4/MDP5 in line with the DPU driver whose dpu_kms_init() doesn't
perform error cleanup on the failure. Let the common path own the
cleanup, instead of freeing the KMS from their error paths.

The crash trace for the reference:

  __lock_acquire from lock_acquire (kernel/locking/lockdep.c:5906 kernel/locking/lockdep.c:5863)
  lock_acquire from touch_wq_lockdep_map (kernel/workqueue.c:4094 (discriminator 1))
  touch_wq_lockdep_map from __flush_workqueue (kernel/workqueue.c:4136)
  __flush_workqueue from msm_drm_kms_uninit (drivers/gpu/drm/msm/msm_kms.c:243 (discriminator 33))
  msm_drm_kms_uninit from msm_drm_uninit (drivers/gpu/drm/msm/msm_drv.c:93)
  msm_drm_uninit from msm_drm_init (drivers/gpu/drm/msm/msm_drv.c:184)
  msm_drm_init from try_to_bring_up_aggregate_device (drivers/base/component.c:249 drivers/base/component.c:227)
  try_to_bring_up_aggregate_device from __component_add (drivers/base/component.c:269 drivers/base/component.c:748)
  __component_add from dsi_host_attach (drivers/gpu/drm/msm/dsi/dsi_host.c:1739)
  dsi_host_attach from mipi_dsi_attach (drivers/gpu/drm/drm_mipi_dsi.c:383)
  mipi_dsi_attach from sharp_nt_panel_probe (drivers/gpu/drm/panel/panel-sharp-ls043t1le01.c:247)

Fixes: 506efcba31 ("drm/msm: carve out KMS code from msm_drv.c")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/742068/
Link: https://lore.kernel.org/r/20260723-msm-fix-crash-v1-1-78fb4721c2d9@oss.qualcomm.com
History 2026-07-31 16:55:05 +03:00
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Linux kernel
============

The Linux kernel is the core of any Linux operating system. It manages hardware,
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-----------

* Report a bug: See Documentation/admin-guide/reporting-issues.rst
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-----------------------

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============

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For Specific Users
==================

New Kernel Developer
--------------------

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* Getting Started: Documentation/process/development-process.rst
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* Core APIs: Documentation/core-api/index.rst

Academic Researcher
-------------------

Explore the kernel's architecture and internals:

* Researcher Guidelines: Documentation/process/researcher-guidelines.rst
* Memory Management: Documentation/mm/index.rst
* Scheduler: Documentation/scheduler/index.rst
* Networking Stack: Documentation/networking/index.rst
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---------------

Security documentation and hardening guides:

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-----------------------------

Maintain and stabilize kernel versions:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
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--------------------

Configure, tune, and troubleshoot Linux systems:

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----------

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---------------

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-----------------------

Package and distribute the kernel:

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AI Coding Assistant
-------------------

CRITICAL: If you are an LLM or AI-powered coding assistant, you MUST read and
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* Documentation/process/coding-assistants.rst

This documentation contains essential requirements about licensing, attribution,
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=========================

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