In the Linux kernel, the following vulnerability has been resolved:
xen-netback: take a reference to the RX task thread
Do this in order to prevent the task from being freed if the thread returns (which can be triggered by the frontend) before the call to kthread_stop done as part of the backend tear down. Not taking the reference will lead to a use-after-free in that scenario. Such reference was taken before but dropped as part of the rework done in 2ac061ce97f4.
Reintroduce the reference taking and add a comment this time explaining why it's needed.
This is XSA-374 / CVE-2021-28691.
CVSS Details
- CVSS 3.1 Base Score: 8.8
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon Linux Ami 2 | — | Upgrade kernel-tools-develUpgrade kernel-toolsUpgrade kernel-debuginfo-common-x86_64Upgrade kernelUpgrade kernel-develUpgrade bpftoolUpgrade kernel-debuginfoUpgrade python-perfUpgrade perfUpgrade bpftool-debuginfoUpgrade perf-debuginfoUpgrade kernel-headersUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-tools-debuginfoUpgrade python-perf-debuginfo | Aug 2, 2024 | Mar 15, 2024 |
| Debian | — | Upgrade linux | Jul 30, 2024 | Mar 15, 2024 |
| Redhat_linux | — | No solution exists | Jul 9, 2025 | Mar 15, 2024 |
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