{"id":"CVE-2026-31666","title":"btrfs: fix incorrect return value after changing leaf in lookup_extent_data_ref()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix incorrect return value after changing leaf in lookup_extent_data_ref()\n\nAfter commit 1618aa3c2e01 (\"btrfs: simplify return variables in\nlookup_extent_data_re…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 1618aa3c2e0163f5ac34d514ae89474521910536 < 4125a194db4a6cf91f619f38788272651cb97dce","Linux >= 1618aa3c2e0163f5ac34d514ae89474521910536 < 450e6a685d0cad95b15f8af152057bd0bf79f50b","Linux >= 1618aa3c2e0163f5ac34d514ae89474521910536 < ab1e022379c3c811aa72da8eb0c7507859a1d0f5","Linux >= 1618aa3c2e0163f5ac34d514ae89474521910536 < 316fb1b3169efb081d2db910cbbfef445afa03b9","Linux 6.10"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T15:11:52.641665Z"},"published":"2026-04-24","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:20:21.898Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-31666","references":[{"url":"https://git.kernel.org/stable/c/4125a194db4a6cf91f619f38788272651cb97dce"},{"url":"https://git.kernel.org/stable/c/450e6a685d0cad95b15f8af152057bd0bf79f50b"},{"url":"https://git.kernel.org/stable/c/ab1e022379c3c811aa72da8eb0c7507859a1d0f5"},{"url":"https://git.kernel.org/stable/c/316fb1b3169efb081d2db910cbbfef445afa03b9"}],"tags":["cve.org"],"epss":0.00175,"epssPercentile":0.06541,"ingestedAt":"2026-10-16T17:24:46.668Z","slug":"CVE-2026-31666","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix incorrect return value after changing leaf in lookup_extent_data_ref()\n\nAfter commit 1618aa3c2e01 (\"btrfs: simplify return variables in\nlookup_extent_data_ref()\"), the err and ret variables were merged into\na single ret variable. However, when btrfs_next_leaf() returns 0\n(success), ret is overwritten from -ENOENT to 0. If the first key in\nthe next leaf does not match (different objectid or type), the function\nreturns 0 instead of -ENOENT, making the caller believe the lookup\nsucceeded when it did not. This can lead to operations on the wrong\nextent tree item, potentially causing extent tree corruption.\n\nFix this by returning -ENOENT directly when the key does not match,\ninstead of relying on the ret variable.\n\n## Affected\n\n- `Linux >= 1618aa3c2e0163f5ac34d514ae89474521910536 < 4125a194db4a6cf91f619f38788272651cb97dce`\n- `Linux >= 1618aa3c2e0163f5ac34d514ae89474521910536 < 450e6a685d0cad95b15f8af152057bd0bf79f50b`\n- `Linux >= 1618aa3c2e0163f5ac34d514ae89474521910536 < ab1e022379c3c811aa72da8eb0c7507859a1d0f5`\n- `Linux >= 1618aa3c2e0163f5ac34d514ae89474521910536 < 316fb1b3169efb081d2db910cbbfef445afa03b9`\n- `Linux 6.10`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}