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The atmel_hlcdc_plane_atomic_duplicate_state() callback was copying the atmel_hlcdc_plane state structure without properly duplicating the drm_plane_state. In particular, state->commit remained set to the old state commit, which can lead to a use-after-free in the next drm_atomic_commit() call. Fix this by calling __drm_atomic_helper_duplicate_plane_state(), which correctly clones the base drm_plane_state (including the ->commit pointer). It has been seen when closing and re-opening the device node while another DRM client (e.g. fbdev) is still attached: ============================================================================= BUG kmalloc-64 (Not tainted): Poison overwritten ----------------------------------------------------------------------------- 0xc611b344-0xc611b344 @offset=836. First byte 0x6a instead of 0x6b FIX kmalloc-64: Restoring Poison 0xc611b344-0xc611b344=0x6b Allocated in drm_atomic_helper_setup_commit+0x1e8/0x7bc age=178 cpu=0 pid=29 drm_atomic_helper_setup_commit+0x1e8/0x7bc drm_atomic_helper_commit+0x3c/0x15c drm_atomic_commit+0xc0/0xf4 drm_framebuffer_remove+0x4cc/0x5a8 drm_mode_rmfb_work_fn+0x6c/0x80 process_one_work+0x12c/0x2cc worker_thread+0x2a8/0x400 kthread+0xc0/0xdc ret_from_fork+0x14/0x28 Freed in drm_atomic_helper_commit_hw_done+0x100/0x150 age=8 cpu=0 pid=169 drm_atomic_helper_commit_hw_done+0x100/0x150 drm_atomic_helper_commit_tail+0x64/0x8c commit_tail+0x168/0x18c drm_atomic_helper_commit+0x138/0x15c drm_atomic_commit+0xc0/0xf4 drm_atomic_helper_set_config+0x84/0xb8 drm_mode_setcrtc+0x32c/0x810 drm_ioctl+0x20c/0x488 sys_ioctl+0x14c/0xc20 ret_fast_syscall+0x0/0x54 Slab 0xef8bc360 objects=21 used=16 fp=0xc611b7c0 flags=0x200(workingset|zone=0) Object 0xc611b340 @offset=832 fp=0xc611b7c0 Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com> Reviewed-by: Manikandan Muralidharan <manikandan.m@microchip.com> Link: https://patch.msgid.link/20251024-lcd_fixes_mainlining-v1-2-79b615130dc3@microchip.com Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
Linux kernel ============ The Linux kernel is the core of any Linux operating system. It manages hardware, system resources, and provides the fundamental services for all other software. Quick Start ----------- * Report a bug: See Documentation/admin-guide/reporting-issues.rst * Get the latest kernel: https://kernel.org * Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst * Join the community: https://lore.kernel.org/ Essential Documentation ----------------------- All users should be familiar with: * Building requirements: Documentation/process/changes.rst * Code of Conduct: Documentation/process/code-of-conduct.rst * License: See COPYING Documentation can be built with make htmldocs or viewed online at: https://www.kernel.org/doc/html/latest/ Who Are You? ============ Find your role below: * New Kernel Developer - Getting started with kernel development * Academic Researcher - Studying kernel internals and architecture * Security Expert - Hardening and vulnerability analysis * Backport/Maintenance Engineer - Maintaining stable kernels * System Administrator - Configuring and troubleshooting * Maintainer - Leading subsystems and reviewing patches * Hardware Vendor - Writing drivers for new hardware * Distribution Maintainer - Packaging kernels for distros For Specific Users ================== New Kernel Developer -------------------- Welcome! Start your kernel development journey here: * Getting Started: Documentation/process/development-process.rst * Your First Patch: Documentation/process/submitting-patches.rst * Coding Style: Documentation/process/coding-style.rst * Build System: Documentation/kbuild/index.rst * Development Tools: Documentation/dev-tools/index.rst * Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst * 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 * Filesystems: Documentation/filesystems/index.rst * RCU (Read-Copy Update): Documentation/RCU/index.rst * Locking Primitives: Documentation/locking/index.rst * Power Management: Documentation/power/index.rst Security Expert --------------- Security documentation and hardening guides: * Security Documentation: Documentation/security/index.rst * LSM Development: Documentation/security/lsm-development.rst * Self Protection: Documentation/security/self-protection.rst * Reporting Vulnerabilities: Documentation/process/security-bugs.rst * CVE Procedures: Documentation/process/cve.rst * Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst * Security Features: Documentation/userspace-api/seccomp_filter.rst Backport/Maintenance Engineer ----------------------------- Maintain and stabilize kernel versions: * Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst * Backporting Guide: Documentation/process/backporting.rst * Applying Patches: Documentation/process/applying-patches.rst * Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst * Git for Maintainers: Documentation/maintainer/configure-git.rst System Administrator -------------------- Configure, tune, and troubleshoot Linux systems: * Admin Guide: Documentation/admin-guide/index.rst * Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst * Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst * Tracing/Debugging: Documentation/trace/index.rst * Performance Security: Documentation/admin-guide/perf-security.rst * Hardware Monitoring: Documentation/hwmon/index.rst Maintainer ---------- Lead kernel subsystems and manage contributions: * Maintainer Handbook: Documentation/maintainer/index.rst * Pull Requests: Documentation/maintainer/pull-requests.rst * Managing Patches: Documentation/maintainer/modifying-patches.rst * Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst * Development Process: Documentation/process/maintainer-handbooks.rst * Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst * Git Configuration: Documentation/maintainer/configure-git.rst Hardware Vendor --------------- Write drivers and support new hardware: * Driver API Guide: Documentation/driver-api/index.rst * Driver Model: Documentation/driver-api/driver-model/driver.rst * Device Drivers: Documentation/driver-api/infrastructure.rst * Bus Types: Documentation/driver-api/driver-model/bus.rst * Device Tree Bindings: Documentation/devicetree/bindings/ * Power Management: Documentation/driver-api/pm/index.rst * DMA API: Documentation/core-api/dma-api.rst Distribution Maintainer ----------------------- Package and distribute the kernel: * Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst * ABI Documentation: Documentation/ABI/README * Kernel Configuration: Documentation/kbuild/kconfig.rst * Module Signing: Documentation/admin-guide/module-signing.rst * Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst * Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst Communication and Support ========================= * Mailing Lists: https://lore.kernel.org/ * IRC: #kernelnewbies on irc.oftc.net * Bugzilla: https://bugzilla.kernel.org/ * MAINTAINERS file: Lists subsystem maintainers and mailing lists * Email Clients: Documentation/process/email-clients.rst