CVE-2024-40909: bpf: Fix a potential use-after-free in bpf_link_free()
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix a potential use-after-free in bpflinkfree()
After commit 1a80dbcb2dba, bpflink can be freed by link->ops->deallocdeferred, but the code still tests and uses link->ops->dealloc afterward, which leads to a use-after-free as reported by syzbot. Actually, one of them should be sufficient, so just call one of them instead of both. Also add a WARNON() in case of any problematic implementation.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 5.10.223-1Fixed in 5.10.234-1Fixed in 6.1.129-1Fixed in 6.1.135-1Fixed in 6.12.25-1 - Upgrade
Upgrade
Linux kernel (bpf)to a version that resolves this vulnerability.Patch bpf: Fix a potential use-after-free in bpf_link_free()
Event History
Frequently Asked Questions
What is the severity of CVE-2024-40909?
CVE-2024-40909 has a moderate severity rating due to the potential for use-after-free vulnerabilities in the Linux kernel.
How do I fix CVE-2024-40909?
To remediate CVE-2024-40909, update the Linux kernel to a version that includes the fix, specifically above version 6.6.35 or 6.9.6.
Which versions of the Linux kernel are affected by CVE-2024-40909?
CVE-2024-40909 affects Linux kernel versions between 6.6.26 and 6.6.35, and versions around 6.9.0 to 6.9.6, including 6.10-rc1 and 6.10-rc2.
Is CVE-2024-40909 being actively exploited?
There is no current public information indicating that CVE-2024-40909 is actively being exploited.
Where can I find more information about CVE-2024-40909?
For detailed information on CVE-2024-40909, refer to the Linux kernel changelogs and security advisory documentation.