Description
An issue was discovered in the Linux kernel 5.5 through 5.7.9, as used in Xen through 4.13.x for x86 PV guests. An attacker may be granted the I/O port permissions of an unrelated task. This occurs because tss_invalidate_io_bitmap mishandling causes a loss of synchronization between the I/O bitmaps of TSS and Xen, aka CID-cadfad870154.
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 | 5.7.10-1 | — |
| Debian 13 | linux | 5.7.10-1 | — |
| Debian 12 | linux | 5.7.10-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | linux-oem-5.6 | 5.6.0-1023.23 | — |
| Ubuntu 20.04 LTS | linux-raspi2 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +8 | 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
- http://xenbits.xen.org/xsa/advisory-329.html
- https://github.com/torvalds/linux/commit/cadfad870154e14f745ec845708bc17d166065f2
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=cadfad870154e14f745ec845708bc17d166065f2
- [oss-security] 20200721 Xen Security Advisory 329 v3 (CVE-2020-15852) - Linux ioperm bitmap context switching issues mailing-list
- https://security.netapp.com/advisory/ntap-20200810-0001/