{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-74481", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-74481", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-08-15T12:27:14.441Z", "updatedAt": "2026-10-16T19:05:48.983Z", "importedAt": "2026-10-24T01:58:30.346Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "mm/page_reporting: use system_freezable_wq to fix UAF during suspend", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/page_reporting: use system_freezable_wq to fix UAF during suspend\n\nDuring PM freeze (e.g. S3 suspend or S4 hibernation), device drivers like\nvirtio_balloon reset their underlying virtio devices and delete their\nvirtqueues via vdev->config->del_vqs().\n\nHowever, page reporting work (page_reporting_process) was scheduled on the\nglobal system_wq. Because system_wq lacks the WQ_FREEZABLE flag, the PM\nfreezer skips it, leaving page_reporting_process active during suspend.\n\nIf pages are freed into the buddy allocator while suspending (for example,\nwhen core MM invokes the balloon shrinker during S4 hibernation image\nsaving), page reporting triggers virtballoon_free_page_report() on deleted\nvirtqueues, resulting in a Use-After-Free / General Protection Fault:\n\n [ 196.795226] general protection fault, probably for non-canonical address 0xaa1436fe70dae6df: 0000 [#1] SMP NOPTI\n [ 196.825967] Workqueue: events page_reporting_process\n [ 196.831038] RIP: 0010:virtqueue_add_split+0x233/0x4c0 [virtio_ring]\n [ 196.927073] virtballoon_free_page_report+0x3a/0xe0 [virtio_balloon]\n [ 196.946943] page_reporting_process+0x370/0x4f0\n\nFix this by switching page reporting work to system_freezable_wq. This\nensures that the PM freezer pauses page_reporting_process before device\ndrivers destroy their reporting virtqueues. Because the reporting worker\nis frozen, memory reclamation/freeing (e.g. via shrinker execution) can\nsafely return pages to MM during freeze without triggering unfrozen\nreporting work on deleted virtqueues.\n\nThis aligns with the driver's existing design. The comment in\nvirtballoon_freeze() states:\n /*\n * The workqueue is already frozen by the PM core before this\n * function is called.\n */\n\nTesting:\nI have verified these fixes using Google’s virtualization infrastructure\nby running continuous suspend/resume iterations (40+ cycles) while\nchurning memory using stress-ng (`stress-ng --vm 4 --vm-bytes 60%\n--timeout 1`) to constantly create free pages for the buddy allocator. We\nalso set the `page_reporting_order` parameter to 0 to make the page\nreporting worker highly sensitive, forcing it to pick up any 4K free\npages. This confirmed that the UAF crashes are no longer reproducible.", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "36e66c554b5c6a9d17a229faca7a61693527b0bd", "status": "affected", "versionType": "git", "lessThan": "a4c60046052777ca1dcc83fe3ece2a5136b301f1" }, { "version": "36e66c554b5c6a9d17a229faca7a61693527b0bd", "status": "affected", "versionType": "git", "lessThan": "b2c094e98f8bb823b3ae475f7169fe2091c40c6d" }, { "version": "36e66c554b5c6a9d17a229faca7a61693527b0bd", "status": "affected", "versionType": "git", "lessThan": "992f270fd808338fbae1f498a5e325e7e2e20368" }, { "version": "36e66c554b5c6a9d17a229faca7a61693527b0bd", "status": "affected", "versionType": "git", "lessThan": "f978048326570047e8216e81a67f9c71ef2bb1b1" }, { "version": "36e66c554b5c6a9d17a229faca7a61693527b0bd", "status": "affected", "versionType": "git", "lessThan": "450f35f4d5a682a0796757e52295df58ddb63bc9" }, { "version": "36e66c554b5c6a9d17a229faca7a61693527b0bd", "status": "affected", "versionType": "git", "lessThan": "b11907c905fa08eda925395f0724b7a409870f65" }, { "version": "36e66c554b5c6a9d17a229faca7a61693527b0bd", "status": "affected", "versionType": "git", "lessThan": "faf439b5fa7b231120eac4f7a617e0bfd4f6f5c7" }, { "version": "36e66c554b5c6a9d17a229faca7a61693527b0bd", "status": "affected", "versionType": "git", "lessThan": "0b45f6927a14914ff685fe0e6f9d11232a1e03df" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "5.7", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "5.7" }, { "version": "5.10.265", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.216", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.183", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.151", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.103", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.44", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.1.8", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.1.*" }, { "version": "7.2", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }