{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64600", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.799Z", "datePublished": "2026-07-23T05:46:56.149Z", "dateUpdated": "2026-08-17T04:58:23.073Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:58:23.073Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfs: resample the data fork mapping after cycling ILOCK\n\nxfs_reflink_fill_{cow_hole,delalloc} are both presented with an inode,\na data fork mapping, and a cow fork mapping. Unfortunately, these two\nhelpers cycle the ILOCK to grab a transaction, which means that the\nmappings are stale as soon as we reacquire the ILOCK. Currently we\nrefresh the cow fork mapping by re-calling xfs_find_trim_cow_extent, but\nwe don't refresh the data fork mapping beforehand, which means that the\nxfs_bmap_trim_cow in that function queries the refcount btree about the\nwrong physical blocks and returns an inaccurate value in *shared.\n\nIf *shared is now false, the directio write proceeds with a stale data\nfork mapping. Fix this by querying the data fork mapping if the\nsequence counter changes across the ILOCK cycle." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - Exploitation uses local FICLONE and concurrent O_DIRECT write syscalls against an XFS filesystem.\nAC:L - The attacker controls both racing writers, can amplify the transaction-allocation window, and demonstrated exploitation typically succeeds within seconds.\nPR:L - A basic unprivileged local user needs only read access to the protected source and write access to a scratch file; no capabilities are required.\nUI:N - The attacker creates the reflink and triggers both sides of the race without any victim action.\nS:U - This is a standard local kernel-mediated privilege escalation affecting resources within the host operating system's existing security authority.\nC:H - Overwriting /etc/passwd or a readable SUID-root binary yields full root access and consequently unrestricted access to system-confidential data.\nI:H - The stale physical mapping provides attacker-controlled persistent writes into protected readable files while preserving their ownership and SUID metadata, enabling full root compromise.\nA:H - The attacker can persistently corrupt boot-critical binaries or configuration files and, after obtaining root, cause complete system unavailability." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/xfs/xfs_reflink.c" ], "versions": [ { "version": "3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5", "lessThan": "dc11be133efca5fe3a2fb02b016dee825cc12f18", "status": "affected", "versionType": "git" }, { "version": "3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5", "lessThan": "b8c9aa832b52680ee40d6cab0efb081f9a69df05", "status": "affected", "versionType": "git" }, { "version": "3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5", "lessThan": "50f0012da1040f69a4e788cd9aed587c9a04983f", "status": "affected", "versionType": "git" }, { "version": "3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5", "lessThan": "e705d81a7193dd19e69b8e2bad4696d78a4ea075", "status": "affected", "versionType": "git" }, { "version": "3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5", "lessThan": "206c09b04dc5469c7ff14d8aceff2d47c88078d9", "status": "affected", "versionType": "git" }, { "version": "3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5", "lessThan": "44f891bc088958399eec27f7604928694aa35581", "status": "affected", "versionType": "git" }, { "version": "3c68d44a2b49a0ac9165faa9c191e1e618c8a8d5", "lessThan": "2f4acd0fcd862e22eab45690ec2c08c80b6ef2e7", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/xfs/xfs_reflink.c" ], "versions": [ { "version": "4.11", "status": "affected" }, { "version": "0", "lessThan": "4.11", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.96", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.4", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "6.12.96" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "6.18.39" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "7.1.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/dc11be133efca5fe3a2fb02b016dee825cc12f18" }, { "url": "https://git.kernel.org/stable/c/b8c9aa832b52680ee40d6cab0efb081f9a69df05" }, { "url": "https://git.kernel.org/stable/c/50f0012da1040f69a4e788cd9aed587c9a04983f" }, { "url": "https://git.kernel.org/stable/c/e705d81a7193dd19e69b8e2bad4696d78a4ea075" }, { "url": "https://git.kernel.org/stable/c/206c09b04dc5469c7ff14d8aceff2d47c88078d9" }, { "url": "https://git.kernel.org/stable/c/44f891bc088958399eec27f7604928694aa35581" }, { "url": "https://git.kernel.org/stable/c/2f4acd0fcd862e22eab45690ec2c08c80b6ef2e7" }, { "url": "https://cdn2.qualys.com/advisory/2026/07/22/RefluXFS.txt" } ], "title": "xfs: resample the data fork mapping after cycling ILOCK", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "http://www.openwall.com/lists/oss-security/2026/07/22/14" }, { "url": "http://www.openwall.com/lists/oss-security/2026/07/22/18" }, { "url": "http://www.openwall.com/lists/oss-security/2026/07/22/19" }, { "url": "http://www.openwall.com/lists/oss-security/2026/07/31/3" }, { "url": "http://www.openwall.com/lists/oss-security/2026/08/03/4" }, { "url": "http://www.openwall.com/lists/oss-security/2026/08/03/8" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2026-08-03T20:31:20.507Z" } } ] } }