CVE-2021-47111
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.24%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.24% probability · 14th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/107866a8eb0b664675a260f1ba0655010fac1e08Patch
- https://git.kernel.org/stable/c/6b53db8c4c14b4e7256f058d202908b54a7b85b4Patch
- https://git.kernel.org/stable/c/caec9bcaeb1a5f03f2d406305355c853af10c13ePatch
- https://git.kernel.org/stable/c/107866a8eb0b664675a260f1ba0655010fac1e08Patch
- https://git.kernel.org/stable/c/6b53db8c4c14b4e7256f058d202908b54a7b85b4Patch
- https://git.kernel.org/stable/c/caec9bcaeb1a5f03f2d406305355c853af10c13ePatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.