CVE-2022-49697
MediumIn the Linux kernel, the following vulnerability has been resolved: bpf: Fix request_sock leak in sk lookup helpers A customer reported a request_socket leak in a Calico cloud environment. We found that a BPF program was doing a socket lookup with takes a refcnt on the socket and that it was finding the request_socket but returning the parent LISTEN socket via sk_to_full_sk() without decrementing the child request socket 1st, resulting in request_sock slab object leak. This patch retains the existing behaviour of returning full socks to the caller but it also decrements the child request_socket if one is present before doing so to prevent the leak. Thanks to Curtis Taylor for all the help in diagnosing and testing this. And thanks to Antoine Tenart for the reproducer and patch input. v2 of this patch contains, refactor as per Daniel Borkmann's suggestions to validate RCU flags on the listen socket so that it balances with bpf_sk_release() and update comments as per Martin KaFai Lau's suggestion. One small change to Daniels suggestion, put "sk = sk2" under "if (sk2 != sk)" to avoid an extra instruction.
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-401CVE-2022-49697 is a Memory Leak vulnerability
What is Memory Leak?
The product does not release memory after use, causing gradual resource exhaustion. Learn more on MITRE CWE
Affected versions
Linux kernel versions
5.2
and later are affected. Fixed in
5.4.202,
5.10.127,
5.15.51,
5.18.8,
5.19
and their respective stable series.
References
The following references provide additional information about CVE-2022-49697 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/3046a827316c0e55fc563b4fb78c93b9ca5c7c37
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PatchKernel patch commithttps://git.kernel.org/stable/c/516760f1d2979903eaad5b437256913c5cd98416
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PatchKernel patch commithttps://git.kernel.org/stable/c/5a62b5ba4c0ce8315b6382cd4ace81b48cd121cd
Frequently asked questions
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What is CVE-2022-49697?
CVE-2022-49697 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a Memory Leak flaw (CWE-401) . It affects Linux kernel versions from 5.2 onward and has been patched in 5.4.202, 5.10.127, 5.15.51 and others. CVE-2022-49697 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2022-49697?
CVE-2022-49697 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2022-49697?
Yes — CVE-2022-49697 has been patched. Fixed versions include 5.4.202, 5.10.127, 5.15.51 and others. If you are running Linux kernel 5.2 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2022-49697 actively exploited?
No — CVE-2022-49697 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Memory Leak (CWE-401)?
The product does not release memory after use, causing gradual resource exhaustion. View CWE-401 on MITRE CWE →