Description
The block subsystem in the Linux kernel before 5.2 has a use-after-free that can lead to arbitrary code execution in the kernel context and privilege escalation, aka CID-c3e2219216c9. This is related to blk_mq_free_rqs and blk_cleanup_queue.
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.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | linux-riscv +1 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +13 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
References
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.2
- https://sites.google.com/view/syzscope/kasan-use-after-free-read-in-blk_mq_free_rqs
- https://syzkaller.appspot.com/bug?id=36fe241584203cf394d44560a42e3430434f1213
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c3e2219216c92919a6bd1711f340f5faa98695e6
- https://security.netapp.com/advisory/ntap-20210629-0006/