ghsa-f5h7-3v7h-xww3
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
mm/mglru: fix div-by-zero in vmpressure_calc_level()
evict_folios() uses a second pass to reclaim folios that have gone through page writeback and become clean before it finishes the first pass, since folio_rotate_reclaimable() cannot handle those folios due to the isolation.
The second pass tries to avoid potential double counting by deducting scan_control->nr_scanned. However, this can result in underflow of nr_scanned, under a condition where shrink_folio_list() does not increment nr_scanned, i.e., when folio_trylock() fails.
The underflow can cause the divisor, i.e., scale=scanned+reclaimed in vmpressure_calc_level(), to become zero, resulting in the following crash:
[exception RIP: vmpressure_work_fn+101] process_one_work at ffffffffa3313f2b
Since scan_control->nr_scanned has no established semantics, the potential double counting has minimal risks. Therefore, fix the problem by not deducting scan_control->nr_scanned in evict_folios().
{
"affected": [],
"aliases": [
"CVE-2024-42316"
],
"database_specific": {
"cwe_ids": [
"CWE-369"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-08-17T09:15:11Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/mglru: fix div-by-zero in vmpressure_calc_level()\n\nevict_folios() uses a second pass to reclaim folios that have gone through\npage writeback and become clean before it finishes the first pass, since\nfolio_rotate_reclaimable() cannot handle those folios due to the\nisolation.\n\nThe second pass tries to avoid potential double counting by deducting\nscan_control-\u003enr_scanned. However, this can result in underflow of\nnr_scanned, under a condition where shrink_folio_list() does not increment\nnr_scanned, i.e., when folio_trylock() fails.\n\nThe underflow can cause the divisor, i.e., scale=scanned+reclaimed in\nvmpressure_calc_level(), to become zero, resulting in the following crash:\n\n [exception RIP: vmpressure_work_fn+101]\n process_one_work at ffffffffa3313f2b\n\nSince scan_control-\u003enr_scanned has no established semantics, the potential\ndouble counting has minimal risks. Therefore, fix the problem by not\ndeducting scan_control-\u003enr_scanned in evict_folios().",
"id": "GHSA-f5h7-3v7h-xww3",
"modified": "2024-08-22T18:31:20Z",
"published": "2024-08-17T09:30:25Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-42316"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8b671fe1a879923ecfb72dda6caf01460dd885ef"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8de7bf77f21068a5f602bb1e59adbc5ab533509d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a39e38be632f0e1c908d70d1c9cd071c03faf895"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d6510f234c7d117790397f9bb150816b0a954a04"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.