Description (CNA)
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 (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected b2ef9f5a5cb37643ca5def3516c546457074b882 before 234071b4318feaeb27cd2e4e1b16ef6b055adf89; affected b2ef9f5a5cb37643ca5def3516c546457074b882 before bf477abd448c76bb8ea51c9b4f63a3a17c4b6239; affected b2ef9f5a5cb37643ca5def3516c546457074b882 before 5846715b6382dd4c6a69b35a56ca6115d33bc2a0; affected b2ef9f5a5cb37643ca5def3516c546457074b882 before 38f113f81d3f0adc658a4475dd3ecaec985e21d3; affected b2ef9f5a5cb37643ca5def3516c546457074b882 before 9de1eb0aac2862d6144b8db0ec1388e79f8bc3e1; affected b2ef9f5a5cb37643ca5def3516c546457074b882 before 744dd97752ef1076a8d8672bb0d8aa2c7abc1144 |
| Linux / Linux | affected 5.8; unaffected 0 before 5.8; unaffected 6.1.176 through 6.1.*; unaffected 6.6.140 through 6.6.*; unaffected 6.12.86 through 6.12.*; unaffected 6.18.27 through 6.18.*; unaffected 7.0.4 through 7.0.*; unaffected 7.1 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/234071b4318feaeb27cd2e4e1b16ef6b055adf89
- https://git.kernel.org/stable/c/bf477abd448c76bb8ea51c9b4f63a3a17c4b6239
- https://git.kernel.org/stable/c/5846715b6382dd4c6a69b35a56ca6115d33bc2a0
- https://git.kernel.org/stable/c/38f113f81d3f0adc658a4475dd3ecaec985e21d3
- https://git.kernel.org/stable/c/9de1eb0aac2862d6144b8db0ec1388e79f8bc3e1
- https://git.kernel.org/stable/c/744dd97752ef1076a8d8672bb0d8aa2c7abc1144
ADP enrichment
No English description supplied.
No references supplied.