| Name | CVE-2021-28691 |
| Description | Guest triggered use-after-free in Linux xen-netback A malicious or buggy network PV frontend can force Linux netback to disable the interface and terminate the receive kernel thread associated with queue 0 in response to the frontend sending a malformed packet. Such kernel thread termination will lead to a use-after-free in Linux netback when the backend is destroyed, as the kernel thread associated with queue 0 will have already exited and thus the call to kthread_stop will be performed against a stale pointer. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| linux (PTS) | jessie, jessie (lts) | 3.16.84-1 | vulnerable |
| stretch (security) | 4.9.320-2 | fixed |
| stretch (lts), stretch | 4.9.320-3 | fixed |
| buster | 4.19.249-2 | fixed |
| buster (security) | 4.19.304-1 | fixed |
| bullseye | 5.10.209-2 | fixed |
| bullseye (security) | 5.10.205-2 | fixed |
| bookworm | 6.1.76-1 | fixed |
| bookworm (security) | 6.1.85-1 | fixed |
| trixie | 6.6.15-2 | fixed |
| sid | 6.7.9-2 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| linux | source | jessie | (unfixed) | end-of-life | | |
| linux | source | stretch | (not affected) | | | |
| linux | source | buster | (not affected) | | | |
| linux | source | (unstable) | 5.10.46-1 | | | |
Notes
[buster] - linux <not-affected> (Vulnerable code introduced later)
[stretch] - linux <not-affected> (Vulnerable code introduced later)
https://xenbits.xen.org/xsa/advisory-374.html