{ "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-2026-74482", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-74482", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-08-15T12:27:15.083Z", "updatedAt": "2026-10-16T19:05:49.129Z", "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/huge_memory: unlock i_mmap_rwsem before releasing after-split folios", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/huge_memory: unlock i_mmap_rwsem before releasing after-split folios\n\n__folio_split() keeps dereferencing the mapping after the split:\nshmem_uncharge(mapping->host) and remap_page() while the folios are still\nfrozen/locked, and i_mmap_unlock_read(mapping) at the very end, after the\nafter-split folios have been unlocked and freed.\n\nNothing holds an inode reference across that. The split relies on @folio\n-- which the beyond-EOF drop loop never removes, as it starts at\nfolio_next(folio) -- staying locked and in the page cache to hold off\neviction. But the unlock loop unlocks @folio before i_mmap_unlock_read()\nruns. If the caller's @lock_at is a tail beyond EOF, as memory_failure()\npasses when splitting a poisoned tail of a shmem THP that reaches past\ni_size during truncation, it too is gone from the page cache; so once\n@folio is unlocked no locked, in-cache folio pins the inode, and a\nconcurrent final iput() can evict and RCU-free it before\ni_mmap_unlock_read() touches i_mmap_rwsem:\n\n BUG: KASAN: slab-use-after-free in __up_read+0x634/0x790\n i_mmap_unlock_read include/linux/fs.h:537 [inline]\n __folio_split+0x732/0x1640 mm/huge_memory.c:4100\n try_to_split_thp_page+0xab/0x390 mm/memory-failure.c:1675\n memory_failure+0x1394/0x26e0 mm/memory-failure.c:2470\n\n Freed by task 4601:\n shmem_free_in_core_inode+0x54/0xb0 mm/shmem.c:5177\n evict+0x57f/0xac0 fs/inode.c:870\n\nDo every mapping dereference while @folio still pins the inode: drop\ni_mmap_rwsem right after remap_page(), before the loop that unlocks and\nfrees the after-split folios, and clear @mapping so the exit path does not\nunlock it again. shmem_uncharge() and remap_page() already run before\nthat point, so after this nothing past the unlock loop touches the inode\nor the mapping.\n\nThis is now a rule the split depends on, alongside keeping @folio frozen\nuntil the page cache is updated: no inode or mapping dereference once the\nafter-split folios start being unlocked.", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "status": "affected", "versionType": "git", "lessThan": "bc2f5eabaaf60ec18da70b619a8fba1bfb7dea3a" }, { "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "status": "affected", "versionType": "git", "lessThan": "f87c08060818ebb19bafed37c38244538da25097" }, { "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "status": "affected", "versionType": "git", "lessThan": "6f5c272d71845a669e4c8ee5c72b376e29a0e6e5" }, { "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "status": "affected", "versionType": "git", "lessThan": "be106f7855f03d3128ed0ce70ba74b484a90b473" }, { "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "status": "affected", "versionType": "git", "lessThan": "e3dd774dbfd0b5bc2dbd0995221751b1234f8205" }, { "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "status": "affected", "versionType": "git", "lessThan": "10065fb891651d9541e7a5a2db84c1e656ece4f9" }, { "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "status": "affected", "versionType": "git", "lessThan": "d640efe94d86d3be893d4c19220362546a637e90" }, { "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "status": "affected", "versionType": "git", "lessThan": "e923bd21058ea02fd0dcd3549d151d143fd036e5" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "4.8", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "4.8" }, { "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": "*" } ] } ] } } }