Skip to content
CVE PROGRAM SOURCE RECORD7.8 High

CVE-2026-46280

lib: test_hmm: evict device pages on file close to avoid use-after-free

Read JSON ↗CVE.org ↗
Status
Published
Published
Updated
Assigning organization
Linux

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • b2ef9f5a5cb37643ca5def3516c546457074b882 to < 234071b4318feaeb27cd2e4e1b16ef6b055adf89affected
  • b2ef9f5a5cb37643ca5def3516c546457074b882 to < bf477abd448c76bb8ea51c9b4f63a3a17c4b6239affected
  • b2ef9f5a5cb37643ca5def3516c546457074b882 to < 5846715b6382dd4c6a69b35a56ca6115d33bc2a0affected
  • b2ef9f5a5cb37643ca5def3516c546457074b882 to < 38f113f81d3f0adc658a4475dd3ecaec985e21d3affected
  • b2ef9f5a5cb37643ca5def3516c546457074b882 to < 9de1eb0aac2862d6144b8db0ec1388e79f8bc3e1affected
  • b2ef9f5a5cb37643ca5def3516c546457074b882 to < 744dd97752ef1076a8d8672bb0d8aa2c7abc1144affected

Linux Linux

Default version status: affected

  • 5.8affected
  • 0 to < 5.8unaffected
  • 6.1.176 to ≤ 6.1.*unaffected
  • 6.6.140 to ≤ 6.6.*unaffected
  • 6.12.86 to ≤ 6.12.*unaffected
  • 6.18.27 to ≤ 6.18.*unaffected
  • 7.0.4 to ≤ 7.0.*unaffected
  • 7.1 to ≤ *unaffected

References