Description
get_gate_page in mm/gup.c in the Linux kernel 5.7.x and 5.8.x before 5.8.7 allows privilege escalation because of incorrect reference counting (caused by gate page mishandling) of the struct page that backs the vsyscall page. The result is a refcount underflow. This can be triggered by any 64-bit process that can use ptrace() or process_vm_readv(), aka CID-9fa2dd946743.
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 | 5.8.7-1 | — |
| Debian 13 | linux | 5.8.7-1 | — |
| Debian 12 | linux | 5.8.7-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | linux-raspi2 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +10 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 14.04 LTS | linux +3 | No fix yet | — |
References
- https://www.openwall.com/lists/oss-security/2020/09/08/4
- https://git.kernel.org/linus/9fa2dd946743ae6f30dc4830da19147bf100a7f2
- https://git.kernel.org/linus/8891adc61dce2a8a41fc0c23262b681c3ec4b73a
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.8.7
- [oss-security] 20200910 Re: CVE Request: Linux kernel vsyscall page refcounting error mailing-list
- https://security.netapp.com/advisory/ntap-20201001-0003/