CVE-2020-27171

An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c has an off-by-one error (with a resultant integer underflow) affecting out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory, aka CID-10d2bb2e6b1d.

Weakness

A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value.

Affected Software

Potential Mitigations

References

• http://packetstormsecurity.com/files/162117/Kernel-Live-Patch-Security-Notice-LSN-0075-1.html
• http://www.openwall.com/lists/oss-security/2021/03/24/5
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.8
• https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/patch/?id=10d2bb2e6b1d8c4576c56a748f697dbeb8388899
• https://lists.debian.org/debian-lts-announce/2021/03/msg00035.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FB6LUXPEIRLZH32YXWZVEZAD4ZL6SDK2/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QRTPQE73ANG7D6M4L4PK5ZQDPO4Y2FVD/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T2S3I4SLRNRUQDOFYUS6IUAZMQNMPNLG/
• https://www.openwall.com/lists/oss-security/2021/03/19/3