CVE-2021-29155

medium

Description

An issue was discovered in the Linux kernel through 5.11.x. kernel/bpf/verifier.c performs undesirable out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory. Specifically, for sequences of pointer arithmetic operations, the pointer modification performed by the first operation is not correctly accounted for when restricting subsequent operations.

References

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=073815b756c51ba9d8384d924c5d1c03ca3d1ae4

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=24c109bb1537c12c02aeed2d51a347b4d6a9b76e

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=6f55b2f2a1178856c19bbce2f71449926e731914

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=7fedb63a8307dda0ec3b8969a3b233a1dd7ea8e0

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=9601148392520e2e134936e76788fc2a6371e7be

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=a6aaece00a57fa6f22575364b3903dfbccf5345d

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b658bbb844e28f1862867f37e8ca11a8e2aa94a3

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=f528819334881fd622fdadeddb3f7edaed8b7c9b

https://lists.debian.org/debian-lts-announce/2021/06/msg00019.html

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CUX2CA63453G34C6KYVBLJXJXEARZI2X/

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PAEQ3H6HKNO6KUCGRZVYSFSAGEUX23JL/

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XZASHZVCOFJ4VU2I3BN5W5EPHWJQ7QWX/

https://www.kernel.org

https://www.openwall.com/lists/oss-security/2021/04/18/4

Details

Source: Mitre, NVD

Published: 2021-04-20

Risk Information

CVSS v2

Base Score: 2.1

Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:N

Severity: Low

CVSS v3

Base Score: 5.5

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Severity: Medium