CVE-2024-56638

netfilter: nft_inner: incorrect percpu area handling under softirq

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_inner: incorrect percpu area handling under softirq Softirq can interrupt ongoing packet from process context that is walking over the percpu area that contains inner header offsets. Disable bh and perform three checks before restoring the percpu inner header offsets to validate that the percpu area is valid for this skbuff: 1) If the NFT_PKTINFO_INNER_FULL flag is set on, then this skbuff has already been parsed before for inner header fetching to register. 2) Validate that the percpu area refers to this skbuff using the skbuff pointer as a cookie. If there is a cookie mismatch, then this skbuff needs to be parsed again. 3) Finally, validate if the percpu area refers to this tunnel type. Only after these three checks the percpu area is restored to a on-stack copy and bh is enabled again. After inner header fetching, the on-stack copy is stored back to the percpu area.

N/A
CVSS
Severity:
EPSS 0.04%
Affected: Linux Linux
Affected: Linux Linux
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2024-56638?
CVE-2024-56638 has not yet been assigned a CVSS score.
How to fix CVE-2024-56638?
To fix CVE-2024-56638, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2024-56638 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2024-56638 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2024-56638?
CVE-2024-56638 affects Linux Linux, Linux Linux.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.