{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-98975", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.383Z", "datePublished": "2026-10-23T12:19:48.379Z", "dateUpdated": "2026-10-24T14:09:45.210Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-24T14:09:45.210Z"}, "descriptions": [{"lang": "en", "value": "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."}], "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 - `ioctl(2)` runs `do_vfs_ioctl()`/`vfs_ioctl()` \u2192 `xfs_file_ioctl()` \u2192 `xfs_ioc_exchange_range()` \u2192 `xfs_exchange_mappings()` \u2192 patched `xfs_exchmaps_init_intent()`; all causal file descriptors, offsets, and flags are supplied locally.\nAC:L - On a reflink/exchange-range XFS, the attacker can clone a target block, use chosen `TO_EOF` offsets to strand it past `i_disk_size`, perform a full-range exchange so `xmi_can_exchange_reflink_flags()` clears the flag, and `pwrite` the shared block; no race or external event is required.\nPR:L - `xfs_exchange_range()` requires only read-write scratch-file descriptors and `remap_verify_area(..., true)`, with no `capable()` check; FICLONE requires only read access to the protected source and write access to an attacker-owned destination.\nUI:N - The attacker personally performs FICLONERANGE, the crafted `XFS_IOC_EXCHANGE_RANGE` operations, and the final `pwrite`; no victim must mount media, open a file, or take another action.\nS:U - `xfs_exchmaps_clear_reflink()` breaks CoW isolation between inodes on the same XFS host; using the resulting protected-file overwrite for root access is a standard local privilege escalation, not a VM, IOMMU, or other security-authority escape.\nC:H - The attacker can clone a readable SUID-root binary, then make the faulty non-CoW write alter its physical block without modifying its inode or clearing SUID metadata; executing the corrupted binary can yield root and unrestricted access to host-confidential data.\nI:H - After `xfs_exchmaps_clear_reflink()` removes the flag, `xfs_is_cow_inode()` is false and the iomap write path updates the still-shared block in place, permitting persistent attacker-controlled modification of readable protected files without write permission.\nA:H - The same in-place primitive can corrupt readable boot-critical executables, and overwriting a SUID-root binary can provide root control capable of stopping the host, supporting complete availability loss."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/xfs/libxfs/xfs_exchmaps.c", "fs/xfs/libxfs/xfs_log_format.h", "fs/xfs/xfs_bmap_util.c"], "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"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/xfs/libxfs/xfs_exchmaps.c", "fs/xfs/libxfs/xfs_log_format.h", "fs/xfs/xfs_bmap_util.c"], "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"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.12.114"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.18.57"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "7.2.11"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/1fa2f3a7ef7ee0f2503a4b0afe24bc8c9d0820be"}, {"url": "https://git.kernel.org/stable/c/7d3b9b2c9dc57f93f36c716ab752548cb4db9900"}, {"url": "https://git.kernel.org/stable/c/4756c94260e69ce42612b8220c3614f02f7a11d5"}, {"url": "https://git.kernel.org/stable/c/d84d6c1a7f1e2de9e601703a326a4c1b7b421943"}], "title": "xfs: stop exchanging reflink flags when exchanging mappings", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/xfs/libxfs/xfs_exchmaps.c", "fs/xfs/libxfs/xfs_log_format.h", "fs/xfs/xfs_bmap_util.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "1fa2f3a7ef7ee0f2503a4b0afe24bc8c9d0820be", "status": "affected", "version": "f0bc4d134b46607967bda1205ce3226a1bd95f42", "versionType": "git"}, {"lessThan": "7d3b9b2c9dc57f93f36c716ab752548cb4db9900", "status": "affected", "version": "f0bc4d134b46607967bda1205ce3226a1bd95f42", "versionType": "git"}, {"lessThan": "4756c94260e69ce42612b8220c3614f02f7a11d5", "status": "affected", "version": "f0bc4d134b46607967bda1205ce3226a1bd95f42", "versionType": "git"}, {"lessThan": "d84d6c1a7f1e2de9e601703a326a4c1b7b421943", "status": "affected", "version": "f0bc4d134b46607967bda1205ce3226a1bd95f42", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/xfs/libxfs/xfs_exchmaps.c", "fs/xfs/libxfs/xfs_log_format.h", "fs/xfs/xfs_bmap_util.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "4.9"}, {"lessThan": "4.9", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.114", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.57", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.11", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-98975", "lastModified": "2026-10-24T14:16:50.093", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-10-23T13:17:19.157", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1fa2f3a7ef7ee0f2503a4b0afe24bc8c9d0820be"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4756c94260e69ce42612b8220c3614f02f7a11d5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/7d3b9b2c9dc57f93f36c716ab752548cb4db9900"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d84d6c1a7f1e2de9e601703a326a4c1b7b421943"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}