Description
The ext4_xattr_check_entries function in fs/ext4/xattr.c in the Linux kernel through 4.15.15 does not properly validate xattr sizes, which causes misinterpretation of a size as an error code, and consequently allows attackers to cause a denial of service (get_acl NULL pointer dereference and system crash) via a crafted ext4 image.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | Linux kernel through version 4.15 | Linux kernel through version 4.15 | — |
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 | 4.16.5-1 | — |
| Debian 13 | linux | 4.16.5-1 | — |
| Debian 12 | linux | 4.16.5-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | linux | 4.15.0-24.26 | USN-3695-1 |
| Ubuntu 18.04 LTS | linux-aws | 4.15.0-1011.11 | USN-3695-1 |
| Ubuntu 18.04 LTS | linux-azure | 4.15.0-1014.14 | USN-3695-1 |
| Ubuntu 18.04 LTS | linux-gcp | 4.15.0-1010.10 | USN-3695-1 |
| Ubuntu 18.04 LTS | linux-kvm | 4.15.0-1012.12 | USN-3695-1 |
| Ubuntu 18.04 LTS | linux-oem | 4.15.0-1009.12 | USN-3695-1 |
| Ubuntu 18.04 LTS | linux-raspi2 | 4.15.0-1013.14 | USN-3695-1 |
| Ubuntu 16.04 LTS | linux-gcp +1 | 4.15.0-1014.14~16.04.1 | USN-3695-2 |
| Ubuntu 16.04 LTS | linux-hwe | 4.15.0-24.26~16.04.1 | USN-3695-2 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | perf +14 | 4.14.0-115.el7a | RHSA-2018:2948 |
Advisories 3
- RHSA-2018:2948 Red Hat Security Advisory: kernel-alt security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jul 1, 2026
- USN-3695-1 linux, linux-aws, linux-azure, linux-gcp, linux-kvm, linux-oem, linux-raspi2 vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-3695-2 linux-hwe, linux-azure vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
References
- https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git/commit/?id=ce3fd194fcc6fbdc00ce095a852f22df97baa401
- http://openwall.com/lists/oss-security/2018/03/29/1
- USN-3695-1 vendor-advisory
- USN-3695-2 vendor-advisory
- RHSA-2018:2948 vendor-advisory
- https://bugzilla.kernel.org/show_bug.cgi?id=199185
- https://bugzilla.redhat.com/show_bug.cgi?id=1560793