{"schema":"threatline.record/2","record":{"id":"CVE-2026-98975","aliases":[],"summary":"xfs: stop exchanging reflink flags when exchanging mappings","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfs: stop exchanging reflink flags when exchanging mappings\n\nWhen an exchange covers both files from offset 0 to i_disk_size,\nxmi_can_exchange_reflink_flags() assumes every mapping moved and hands\nthe reflink flag over to the other file.\n\nThat assumption is wrong.  A file can still own shared blocks past\ni_disk_size, e.g. after EXCHANGE_RANGE_TO_EOF sets a smaller size\nwithout unmapping anything.  The flag is cleared anyway, and the next\nwrite to such a block happens in place instead of CoW, corrupting the\nother file that shares it.\n\nCommit a23eca88448e (\"xfs: fix exchange-range reflink flag clearing\nissue with INO1_WRITTEN\") fixed one instance of this.  Rather than add\nanother special case, stop moving the flags.\nxfs_exchmaps_ensure_reflink() already sets the flag on both inodes\nbefore the exchange, so both just keep it.\n\nNothing sets CLEAR_INO{1,2}_REFLINK anymore.  Intents logged by older\nkernels may still carry them; recovery already masks them off, so they\nstay in the log format mask and are ignored.\n\nXFS_IOC_SWAPEXT has the same problem: it moves the reflink flag from\none inode to the other along with the extents.  Just removing that is\nnot enough here: the exchange path flags both inodes up front in\nxfs_exchmaps_ensure_reflink(), but swapext has no such step, so the\ninode receiving the shared extents would be left without the flag.\nSet it on both inodes instead, and make sure both have a CoW fork,\nsince an inode with the reflink flag is expected to have one.\n\nThe flag now stays until FALLOC_FL_UNSHARE_RANGE, xfs_scrub, or a\ntruncate to zero removes it.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98975","source_modified_at":"2026-10-24T14:09:45.210Z","fetched_at":"2026-10-24T14:26:37.433577Z","product":"Linux","vendor":"Linux","versions":[{"version":"f0bc4d134b46607967bda1205ce3226a1bd95f42","lessThan":"1fa2f3a7ef7ee0f2503a4b0afe24bc8c9d0820be","status":"affected","versionType":"git"},{"version":"f0bc4d134b46607967bda1205ce3226a1bd95f42","lessThan":"7d3b9b2c9dc57f93f36c716ab752548cb4db9900","status":"affected","versionType":"git"},{"version":"f0bc4d134b46607967bda1205ce3226a1bd95f42","lessThan":"4756c94260e69ce42612b8220c3614f02f7a11d5","status":"affected","versionType":"git"},{"version":"f0bc4d134b46607967bda1205ce3226a1bd95f42","lessThan":"d84d6c1a7f1e2de9e601703a326a4c1b7b421943","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98975","source_modified_at":"2026-10-24T14:09:45.210Z","fetched_at":"2026-10-24T14:26:37.433577Z","product":"Linux","vendor":"Linux","versions":[{"version":"4.9","status":"affected"},{"version":"0","lessThan":"4.9","status":"unaffected","versionType":"semver"},{"version":"6.12.114","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.57","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.11","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98975","source_modified_at":"2026-10-24T14:09:45.210Z","fetched_at":"2026-10-24T14:26:37.433577Z","package":{"name":"Linux","ecosystem":null},"version":"1fa2f3a7ef7ee0f2503a4b0afe24bc8c9d0820be","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98975","source_modified_at":"2026-10-24T14:09:45.210Z","fetched_at":"2026-10-24T14:26:37.433577Z","package":{"name":"Linux","ecosystem":null},"version":"7d3b9b2c9dc57f93f36c716ab752548cb4db9900","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98975","source_modified_at":"2026-10-24T14:09:45.210Z","fetched_at":"2026-10-24T14:26:37.433577Z","package":{"name":"Linux","ecosystem":null},"version":"4756c94260e69ce42612b8220c3614f02f7a11d5","basis":"first unaffected version stated in the CVE record"}],"cvss":7.8,"severity":"High","kev":{"listed":false},"epss":{"probability":null,"percentile":null,"score_date":null},"published_at":"2026-10-23T12:19:48.379Z","modified_at":"2026-10-24T14:09:45.210Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98975","fetched_at":"2026-10-24T14:26:37.433577Z","source_modified_at":"2026-10-24T14:09:45.210Z"}],"sources":["CVE List"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/1fa2f3a7ef7ee0f2503a4b0afe24bc8c9d0820be"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/7d3b9b2c9dc57f93f36c716ab752548cb4db9900"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/4756c94260e69ce42612b8220c3614f02f7a11d5"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/d84d6c1a7f1e2de9e601703a326a4c1b7b421943"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-24T14:09:45.210Z","content_hash":"d264f45946c432e961ea27b6ac07ec7166673ea2742cf74a0230624cb15f8ae8"}}