Riskcovery

CVE-2021-47111

xen-netback: take a reference to the RX task thread

State
Published
Severity
8.8 High
Published
Mar 15, 2024
Updated
Aug 5, 2026
Reserved
Mar 4, 2024

Read the record on cve.org

Description

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.

Scores

CVSSScoreVectorSource
3.18.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HLinux

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • 2ac061ce97f413bfbbdd768f7d2e0fda2e8170df to before 6b53db8c4c14b4e7256f058d202908b54a7b85b4Affected
  • 2ac061ce97f413bfbbdd768f7d2e0fda2e8170df to before caec9bcaeb1a5f03f2d406305355c853af10c13eAffected
  • 2ac061ce97f413bfbbdd768f7d2e0fda2e8170df to before 107866a8eb0b664675a260f1ba0655010fac1e08Affected
LinuxLinux
  • 5.5Affected
  • before 5.5Not affected
  • 5.10.43 through 5.10.*Not affected
  • 5.12.10 through 5.12.*Not affected
  • 5.13 and laterNot affected

References

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