CVE-2025-38520 Details
Description
In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Don't call mmput from MMU notifier callback If the process is exiting, the mmput inside mmu notifier callback from compactd or fork or numa balancing could release the last reference of mm struct to call exit_mmap and free_pgtable, this triggers deadlock with below backtrace. The deadlock will leak kfd process as mmu notifier release is not called and cause VRAM leaking. The fix is to take mm reference mmget_non_zero when adding prange to the deferred list to pair with mmput in deferred list work. If prange split and add into pchild list, the pchild work_item.mm is not used, so remove the mm parameter from svm_range_unmap_split and svm_range_add_child. The backtrace of hung task: INFO: task python:348105 blocked for more than 64512 seconds. Call Trace: __schedule+0x1c3/0x550 schedule+0x46/0xb0 rwsem_down_write_slowpath+0x24b/0x4c0 unlink_anon_vmas+0xb1/0x1c0 free_pgtables+0xa9/0x130 exit_mmap+0xbc/0x1a0 mmput+0x5a/0x140 svm_range_cpu_invalidate_pagetables+0x2b/0x40 [amdgpu] mn_itree_invalidate+0x72/0xc0 __mmu_notifier_invalidate_range_start+0x48/0x60 try_to_unmap_one+0x10fa/0x1400 rmap_walk_anon+0x196/0x460 try_to_unmap+0xbb/0x210 migrate_page_unmap+0x54d/0x7e0 migrate_pages_batch+0x1c3/0xae0 migrate_pages_sync+0x98/0x240 migrate_pages+0x25c/0x520 compact_zone+0x29d/0x590 compact_zone_order+0xb6/0xf0 try_to_compact_pages+0xbe/0x220 __alloc_pages_direct_compact+0x96/0x1a0 __alloc_pages_slowpath+0x410/0x930 __alloc_pages_nodemask+0x3a9/0x3e0 do_huge_pmd_anonymous_page+0xd7/0x3e0 __handle_mm_fault+0x5e3/0x5f0 handle_mm_fault+0xf7/0x2e0 hmm_vma_fault.isra.0+0x4d/0xa0 walk_pmd_range.isra.0+0xa8/0x310 walk_pud_range+0x167/0x240 walk_pgd_range+0x55/0x100 __walk_page_range+0x87/0x90 walk_page_range+0xf6/0x160 hmm_range_fault+0x4f/0x90 amdgpu_hmm_range_get_pages+0x123/0x230 [amdgpu] amdgpu_ttm_tt_get_user_pages+0xb1/0x150 [amdgpu] init_user_pages+0xb1/0x2a0 [amdgpu] amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu+0x543/0x7d0 [amdgpu] kfd_ioctl_alloc_memory_of_gpu+0x24c/0x4e0 [amdgpu] kfd_ioctl+0x29d/0x500 [amdgpu] (cherry picked from commit a29e067bd38946f752b0ef855f3dfff87e77bec7)
A vulnerability in the Linux kernel's handling of AMD GPU memory can lead to a deadlock and a memory leak in the Video RAM (VRAM). This issue arises when the 'mmput' function is called from the Memory Management Unit (MMU) notifier callback during process termination or memory balancing operations. The premature release of the last memory reference can cause a deadlock, as the process fails to properly clean up, leaving the kernel's graphics processing unit (GPU) memory management in disarray. The deadlock can be observed in a task that becomes unresponsive for an extended period, blocked by the improper handling of memory references. As a result, the kernel's GPU virtual memory management leaks processes, exacerbating the VRAM waste.
The vulnerability has been addressed in the Linux kernel. Users should upgrade to the latest version where this issue has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/145a56bd68f4bff098d59fbc7c263d20dfef4fc4 | kernel.org | Patch |
| https://git.kernel.org/stable/c/a7eb0a25010a674c8fdfbece38353ef7be8c5834 | kernel.org | Patch |
| https://git.kernel.org/stable/c/c1bde9d48e09933c361521720f77a8072083c83a | kernel.org | Patch |
| https://git.kernel.org/stable/c/cf234231fcbc7d391e2135b9518613218cc5347f | kernel.org | Patch |
| https://git.kernel.org/stable/c/e90ee15ce28c61f6d83a0511c3e02e2662478350 | kernel.org | Patch |
| https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html | CVE | Mailing ListThird Party Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-667 | Improper Locking | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 5.15.49, < 5.16 >= 5.18.6, < 5.19 >= 5.19.1, < 6.1.148 >= 6.2, < 6.6.101 >= 6.7, < 6.12.39 >= 6.13, < 6.15.7 5.19 - 5.19 rc2 5.19 rc3 5.19 rc4 5.19 rc5 5.19 rc6 5.19 rc7 5.19 rc8 6.16 rc1 6.16 rc2 6.16 rc3 6.16 rc4 |
CPE
Remediation
| |
| debian debian linux | 11.0 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | kernel.org |
| Jan 7, 2026 | Initial Analysis | [email protected] |
| Nov 3, 2025 | CVE Modified | CVE |
| Aug 16, 2025 | New CVE Received | kernel.org |