lib: test_hmm: evict device pages on file close to avoid use-after-free
Patch series "Minor hmm_test fixes and cleanups".
Two bugfixes a cleanup for the HMM kernel selftests. These were mostly
reported by Zenghui Yu with special thanks to Lorenzo for analysing and
pointing out the problems.
This patch (of 3):
When dmirror_fops_release() is called it frees the dmirror struct but
doesn't migrate device private pages back to system memory first. This
leaves those pages with a dangling zone_device_data pointer to the freed
dmirror.
If a subsequent fault occurs on those pages (eg. during coredump) the
dmirror_devmem_fault() callback dereferences the stale pointer causing a
kernel panic. This was reported [1] when running mm/ksft_hmm.sh on arm64,
where a test failure triggered SIGABRT and the resulting coredump walked
the VMAs faulting in the stale device private pages.
Fix this by calling dmirror_device_evict_chunk() for each devmem chunk in
dmirror_fops_release() to migrate all device private pages back to system
memory before freeing the dmirror struct. The function is moved earlier
in the file to avoid a forward declaration.
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
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Fri, 19 Jun 2026 12:45:00 +0000
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Sun, 14 Jun 2026 05:45:00 +0000
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cvssV3_1
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cvssV3_1
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Tue, 09 Jun 2026 02:15:00 +0000
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| Weaknesses | CWE-476 |
Tue, 09 Jun 2026 00:15:00 +0000
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| Weaknesses | CWE-825 | |
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| Metrics |
threat_severity
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cvssV3_1
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Mon, 08 Jun 2026 19:30:00 +0000
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| Weaknesses | CWE-476 |
Mon, 08 Jun 2026 17:00:00 +0000
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| Description | In the Linux kernel, the following vulnerability has been resolved: lib: test_hmm: evict device pages on file close to avoid use-after-free Patch series "Minor hmm_test fixes and cleanups". Two bugfixes a cleanup for the HMM kernel selftests. These were mostly reported by Zenghui Yu with special thanks to Lorenzo for analysing and pointing out the problems. This patch (of 3): When dmirror_fops_release() is called it frees the dmirror struct but doesn't migrate device private pages back to system memory first. This leaves those pages with a dangling zone_device_data pointer to the freed dmirror. If a subsequent fault occurs on those pages (eg. during coredump) the dmirror_devmem_fault() callback dereferences the stale pointer causing a kernel panic. This was reported [1] when running mm/ksft_hmm.sh on arm64, where a test failure triggered SIGABRT and the resulting coredump walked the VMAs faulting in the stale device private pages. Fix this by calling dmirror_device_evict_chunk() for each devmem chunk in dmirror_fops_release() to migrate all device private pages back to system memory before freeing the dmirror struct. The function is moved earlier in the file to avoid a forward declaration. | |
| Title | lib: test_hmm: evict device pages on file close to avoid use-after-free | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-06-19T12:00:04.813Z
Reserved: 2026-05-13T15:03:33.110Z
Link: CVE-2026-46280
No data.
Status : Received
Published: 2026-06-08T17:16:45.683
Modified: 2026-06-14T06:16:23.060
Link: CVE-2026-46280
OpenCVE Enrichment
Updated: 2026-06-14T06:30:07Z