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.
| Software | From | Fixed in |
|---|---|---|
| linux / linux_kernel | 4.15-rc1 | 4.15-rc1.x |
| linux / linux_kernel | 4.15-rc2 | 4.15-rc2.x |
| linux / linux_kernel | 4.15-rc3 | 4.15-rc3.x |
| linux / linux_kernel | 4.14 | 4.14.8 |