CVE-2021-47317
LowIn the Linux kernel, the following vulnerability has been resolved: powerpc/bpf: Fix detecting BPF atomic instructions Commit 91c960b0056672 ("bpf: Rename BPF_XADD and prepare to encode other atomics in .imm") converted BPF_XADD to BPF_ATOMIC and added a way to distinguish instructions based on the immediate field. Existing JIT implementations were updated to check for the immediate field and to reject programs utilizing anything more than BPF_ADD (such as BPF_FETCH) in the immediate field. However, the check added to powerpc64 JIT did not look at the correct BPF instruction. Due to this, such programs would be accepted and incorrectly JIT'ed resulting in soft lockups, as seen with the atomic bounds test. Fix this by looking at the correct immediate value.
CVSS 3.1 score
3.3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Weakness type
CWE-667CVE-2021-47317 is a Improper Locking vulnerability
What is Improper Locking?
The product does not properly acquire or release a lock, which can lead to unexpected behaviour. Learn more on MITRE CWE
References
The following references provide additional information about CVE-2021-47317 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/0d435b6d94b05dcfd836d758a63145aa566618e2
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PatchKernel patch commithttps://git.kernel.org/stable/c/419ac821766cbdb9fd85872bb3f1a589df05c94c
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PatchKernel patch commithttps://git.kernel.org/stable/c/7284dab07e4d51d453cc42851fae9ec4fac6ef2f
Frequently asked questions
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What is CVE-2021-47317?
CVE-2021-47317 is a Low severity Linux kernel vulnerability with a CVSS score of 3.3 out of 10 , classified as an Improper Locking flaw (CWE-667) . CVE-2021-47317 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-2021-47317?
CVE-2021-47317 has a CVSS score of 3.3 out of 10, rated Low 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:L. -
Is there a patch available for CVE-2021-47317?
No patch is currently available for CVE-2021-47317. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
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Is CVE-2021-47317 actively exploited?
No — CVE-2021-47317 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 Improper Locking (CWE-667)?
The product does not properly acquire or release a lock, which can lead to unexpected behaviour. View CWE-667 on MITRE CWE →