CVE-2021-47317
Linux Powerpc BPF Atomic Instruction Detection Vulnerability
Description
In 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.
INFO
Published Date :
May 21, 2024, 3:15 p.m.
Last Modified :
May 12, 2025, 7:59 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
1.4
Exploitability Score :
1.8
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-47317.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2021-47317 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47317 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
May. 12, 2025
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L Added CWE CWE-667 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.13 up to (excluding) 5.13.4 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.12 up to (excluding) 5.12.19 Added Reference Type CVE: https://git.kernel.org/stable/c/0d435b6d94b05dcfd836d758a63145aa566618e2 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/0d435b6d94b05dcfd836d758a63145aa566618e2 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/419ac821766cbdb9fd85872bb3f1a589df05c94c Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/419ac821766cbdb9fd85872bb3f1a589df05c94c Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/7284dab07e4d51d453cc42851fae9ec4fac6ef2f Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/7284dab07e4d51d453cc42851fae9ec4fac6ef2f Types: Patch -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/0d435b6d94b05dcfd836d758a63145aa566618e2 Added Reference https://git.kernel.org/stable/c/419ac821766cbdb9fd85872bb3f1a589df05c94c Added Reference https://git.kernel.org/stable/c/7284dab07e4d51d453cc42851fae9ec4fac6ef2f -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 28, 2024
Action Type Old Value New Value -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 21, 2024
Action Type Old Value New Value Added Description In 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. Added Reference kernel.org https://git.kernel.org/stable/c/7284dab07e4d51d453cc42851fae9ec4fac6ef2f [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/0d435b6d94b05dcfd836d758a63145aa566618e2 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/419ac821766cbdb9fd85872bb3f1a589df05c94c [No types assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-47317 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-47317
weaknesses.