Description
The Btrfs implementation in the Linux kernel before 3.19 does not ensure that the visible xattr state is consistent with a requested replacement, which allows local users to bypass intended ACL settings and gain privileges via standard filesystem operations (1) during an xattr-replacement time window, related to a race condition, or (2) after an xattr-replacement attempt that fails because the data does not fit.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 3.16.7-ckt9-1 | — |
| Debian 13 | linux | 3.16.7-ckt9-1 | — |
| Debian 12 | linux | 3.16.7-ckt9-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-riscv +6 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +2 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +4 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +3 | No fix yet | — |
| Ubuntu 14.04 LTS | linux | 3.13.0-57.95 | USN-2663-1 |
| Ubuntu 14.04 LTS | linux-lts-utopic | 3.16.0-38.52~14.04.1 | USN-2615-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | linux-azure-fde-5.15 | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 11 SP4 | kernel-ec2 +6 | 3.0.101-108.95.2 | SUSE-SU-2019:14089-1 |
| SLES 11 SP4 | kernel-syms +1 | 3.0.101-108.95.1 | SUSE-SU-2019:14089-1 |
| SLES 11 SP3 | kernel-xen +4 | 3.0.101-0.63.TDC.1 | SUSE-SU-2015:1224-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Live Patching 12 | kgraft-patch-SLE12_Update_1 | 3-2.1 | SUSE-SU-2015:1489-1 |
Advisories 5
- USN-2663-1 linux vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-2615-1 linux-lts-utopic vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2019:14089-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2015:1489-1 Live patch for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2015:1224-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
References
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=5f5bc6b1e2d5a6f827bc860ef2dc5b6f365d1339
- SUSE-SU-2015:1489 vendor-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1205079
- 1032418 vdb-entry
- [oss-security] 20150324 CVE request Linux kernel: fs: btrfs: non-atomic xattr replace operation mailing-list
- SUSE-SU-2015:1224 vendor-advisory
- https://github.com/torvalds/linux/commit/5f5bc6b1e2d5a6f827bc860ef2dc5b6f365d1339