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Vulnerability · Published May 21, 2024 · Assigned by Linux

CVE-2021-47317powerpc/bpf: Fix detecting BPF atomic instructions

High 7.8

In plain English

A high-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities).

Severity (CVSS 3.1)7.8High
Exploit odds (30 days)0.2%top 91.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2021-47317
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2021-47317

Affected products (as reported)

VendorProductVersions
Linux Linux 91c960b0056672e74627776655c926388350fa30 – before 7284dab07e4d51d453cc42851fae9ec4fac6ef2f91c960b0056672e74627776655c926388350fa30 – before 0d435b6d94b05dcfd836d758a63145aa566618e291c960b0056672e74627776655c926388350fa30 – before 419ac821766cbdb9fd85872bb3f1a589df05c94c
Linux Linux 5.12

References