Description
A flaw was found in the crypto subsystem of the Linux kernel before version kernel-4.15-rc4. The "null skcipher" was being dropped when each af_alg_ctx was freed instead of when the aead_tfm was freed. This can cause the null skcipher to be freed while it is still in use leading to a local user being able to crash the system or possibly escalate privileges.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| [UNKNOWN] | kernel | kernel-4.15-rc4 | — |
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 | 4.14.12-1 | — |
| Debian 13 | linux | 4.14.12-1 | — |
| Debian 12 | linux | 4.14.12-1 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | perf +14 | 4.14.0-115.el7a | RHSA-2018:2948 |
Advisories 1
- RHSA-2018:2948 Red Hat Security Advisory: kernel-alt security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jul 1, 2026