CVE-2021-47317
Assigner: Linux
Published: 2024-05-21T14:35:33.212Z
State: PUBLISHED
descriptions: value: 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: product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions: version: 91c960b00566
lessThan: 7284dab07e4d
status: affected
versionType: git
version: 91c960b00566
lessThan: 0d435b6d94b0
status: affected
versionType: git
version: 91c960b00566
lessThan: 419ac821766c
status: affected
versionType: git
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions: version: 5.12
status: affected
version: 0
lessThan: 5.12
status: unaffected
versionType: custom
version: 5.12.19
lessThanOrEqual: 5.12.*
status: unaffected
versionType: custom
version: 5.13.4
lessThanOrEqual: 5.13.*
status: unaffected
versionType: custom
version: 5.14
lessThanOrEqual: *
status: unaffected
versionType: original_commit_for_fix
title: powerpc/bpf: Fix detecting BPF atomic instructions
x_generator: engine: bippy-d175d3acf727