Vulnerability · Published Apr 20, 2021 · Assigned by mitre
CVE-2021-29155
Medium 5.5
In plain English
A medium-severity security flaw in the kernel-tools-libs-devel package (AlmaLinux). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.1% (higher than 65% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | kernel-tools-libs-devel | 4.18.0-348.el8 | ALSA-2021:4356 |
| Debian:12 | linux | 5.10.38-1 | DEBIAN-CVE-2021-29155 |
| Debian:13 | linux | 5.10.38-1 | DEBIAN-CVE-2021-29155 |
| Debian:14 | linux | 5.10.38-1 | DEBIAN-CVE-2021-29155 |
| Ubuntu:22.04:LTS | linux-intel-iot-realtime | no fix listed | UBUNTU-CVE-2021-29155 |
| Ubuntu:24.04:LTS | linux-raspi-realtime | no fix listed | UBUNTU-CVE-2021-29155 |
| Ubuntu:22.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2021-29155 |
Affected products (as reported)
References
- https://www.kernel.org
- https://www.openwall.com/lists/oss-security/2021/04/18/4
- FEDORA-2021-8cd093f639 vendor-advisory
- FEDORA-2021-e6b4847979 vendor-advisory
- FEDORA-2021-a963f04012 vendor-advisory
- [debian-lts-announce] 20210623 [SECURITY] [DLA 2690-1] linux-4.19 security update mailing-list
- 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=6f55b2f2a1178856c19bbce2f71449926e731914
- 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=b658bbb844e28f1862867f37e8ca11a8e2aa94a3
- 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=073815b756c51ba9d8384d924c5d1c03ca3d1ae4
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=f528819334881fd622fdadeddb3f7edaed8b7c9b
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=7fedb63a8307dda0ec3b8969a3b233a1dd7ea8e0