CVE-2021-3444

Summary

The bpf verifier in the Linux kernel did not properly handle mod32 destination register truncation when the source register was known to be 0. A local attacker with the ability to load bpf programs could use this gain out-of-bounds reads in kernel memory leading to information disclosure (kernel memory), and possibly out-of-bounds writes that could potentially lead to code execution. This issue was addressed in the upstream kernel in commit 9b00f1b78809 ("bpf: Fix truncation handling for mod32 dst reg wrt zero") and in Linux stable kernels 5.11.2, 5.10.19, and 5.4.101.

Affected Software

VendorProductVersion RangeStatus
Linuxkerneltrunk < 5.12-rc1affected
Linuxkernel5.11 < 5.11.2affected
Linuxkernel5.10 < 5.10.19affected
Linuxkernel5.4 < 5.4.101affected

Weaknesses

  • CWE-681: CWE-681: Incorrect Conversion between Numeric Types

ADP Enrichment

CVE Program Container

Additional References

References