CVE-2023-53545 in Linux
Summary
by MITRE • 10/04/2025
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: unmap and remove csa_va properly
Root PD BO should be reserved before unmap and remove a bo_va from VM otherwise lockdep will complain.
v2: check fpriv->csa_va is not NULL instead of amdgpu_mcbp (christian)
[14616.936827] WARNING: CPU: 6 PID: 1711 at drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1762 amdgpu_vm_bo_del+0x399/0x3f0 [amdgpu]
[14616.937096] Call Trace:
[14616.937097] <TASK>
[14616.937102] amdgpu_driver_postclose_kms+0x249/0x2f0 [amdgpu]
[14616.937187] drm_file_free+0x1d6/0x300 [drm]
[14616.937207] drm_close_helper.isra.0+0x62/0x70 [drm]
[14616.937220] drm_release+0x5e/0x100 [drm]
[14616.937234] __fput+0x9f/0x280
[14616.937239] ____fput+0xe/0x20
[14616.937241] task_work_run+0x61/0x90
[14616.937246] exit_to_user_mode_prepare+0x215/0x220
[14616.937251] syscall_exit_to_user_mode+0x2a/0x60
[14616.937254] do_syscall_64+0x48/0x90
[14616.937257] entry_SYSCALL_64_after_hwframe+0x63/0xcd
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Analysis
by VulDB Data Team • 05/03/2026
The vulnerability identified as CVE-2023-53545 affects the Linux kernel's AMD GPU driver component, specifically within the direct rendering manager framework. This issue manifests during the cleanup process of GPU memory management operations, where improper handling of virtual memory mappings leads to kernel lockdep warnings and potential system instability. The problem occurs when the driver attempts to unmap and remove a constant shader area virtual address (csa_va) from the virtual memory management system without properly reserving the root page directory backing object first. This sequence violation triggers kernel subsystem warnings that can escalate into system crashes or denial of service conditions.
The technical flaw resides in the amdgpu_vm_bo_del function located in the amdgpu_vm.c source file at line 1762. The vulnerability stems from a missing prerequisite check that should ensure the root page directory backing object is reserved before attempting to remove a bo_va (buffer object virtual address) from the virtual memory space. This improper ordering creates a race condition scenario where lockdep - the kernel's lock dependency validator - detects an invalid locking sequence that could lead to deadlocks or lock corruption. The warning message indicates that the issue occurs during driver post-close operations when the GPU file descriptor is being freed, specifically within the drm_file_free function call chain that eventually leads to amdgpu_driver_postclose_kms.
The operational impact of this vulnerability extends beyond simple kernel warnings, potentially affecting system stability and GPU functionality. When the kernel's lockdep subsystem detects the improper locking sequence, it generates warnings that can flood system logs and indicate deeper memory management issues. In production environments using AMD GPU hardware for graphics rendering, compute workloads, or display operations, this vulnerability could cause application crashes, GPU driver failures, or complete system hangs during GPU resource cleanup operations. The vulnerability particularly affects systems running Linux kernels with AMD GPU support where multiple processes interact with the GPU through DRM interfaces, as the improper cleanup sequence can accumulate and eventually cause system instability.
Mitigation strategies for CVE-2023-53545 involve applying the kernel patch that properly checks for NULL values in fpriv->csa_va before attempting memory management operations, as indicated in the v2 fix approach. System administrators should prioritize updating to kernel versions that include this fix, particularly those containing the drm/amdgpu driver modifications that enforce proper ordering of memory reservation and cleanup operations. The fix implements a more robust NULL pointer check instead of relying on amdgpu_mcbp validation, which aligns with best practices for memory management in kernel space operations. Additionally, monitoring systems should be configured to alert on lockdep warnings related to GPU memory management, as these can serve as early indicators of potential issues. Organizations should also consider implementing proper GPU resource lifecycle management in their applications to minimize the exposure of this vulnerability during normal operation, though the primary mitigation remains kernel-level patching. This vulnerability aligns with CWE-691, which addresses insufficient control flow management in kernel code, and represents a specific instance of improper locking sequence that can lead to system instability.