High 7.8Published Apr 24, 2026

CVE-2026-31666btrfs: fix incorrect return value after changing leaf in lookup_extent_data_ref()

Updated under an hour ago (Oct 28, 2026, 6:40 AM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix incorrect return value after changing leaf in lookup_extent_data_ref() After commit 1618aa3c2e01 ("btrfs: simplify return variables in lookup_extent_data_ref()"), the err and ret variables were merged into a single ret variable. However, when btrfs_next_leaf() returns 0 (success), ret is overwritten from -ENOENT to 0. If the first key in the next leaf does not match (different objectid or type), the function returns 0 instead of -ENOENT, making the caller believe the lookup succeeded when it did not. This can lead to operations on the wrong extent tree item, potentially causing extent tree corruption. Fix this by returning -ENOENT directly when the key does not match, instead of relying on the ret variable.

CVSS: 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-754
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 19, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 1618aa3c2e0163f5ac34d514ae89474521910536 before 4125a194db4a6cf91f619f38788272651cb97dce; 1618aa3c2e0163f5ac34d514ae89474521910536 builds before 450e6a685d0cad95b15f8af152057bd0bf79f50b; from 1618aa3c2e0163f5ac34d514ae89474521910536 before ab1e022379c3c811aa72da8eb0c7507859a1d0f5; 1618aa3c2e0163f5ac34d514ae89474521910536 builds before 316fb1b3169efb081d2db910cbbfef445afa03b9	CNA record
linux linux_kernel linux:linux_kernel	from 6.10.1 before 6.12.82; from 6.13 before 6.18.23; from 6.19 before 6.19.13; 6.10; 7.0; 7.0; 7.0; 7.0; and 3 more ranges	NVD

References

References

https://git.kernel.org/stable/c/4125a194db4a6cf91f619f38788272651cb97dce	patch
https://git.kernel.org/stable/c/450e6a685d0cad95b15f8af152057bd0bf79f50b	patch
https://git.kernel.org/stable/c/ab1e022379c3c811aa72da8eb0c7507859a1d0f5	patch
https://git.kernel.org/stable/c/316fb1b3169efb081d2db910cbbfef445afa03b9	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.