Description
The eBPF RINGBUF bpf_ringbuf_reserve() function in the Linux kernel did not check that the allocated size was smaller than the ringbuf size, allowing an attacker to perform out-of-bounds writes within the kernel and therefore, arbitrary code execution. This issue was fixed via commit 4b81ccebaeee ("bpf, ringbuf: Deny reserve of buffers larger than ringbuf") (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced via 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") (v5.8-rc1).
CVSS breakdown
CVSS 3.1
Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
Affected products
- Linux / Linux kerneltrunk – v5.13-rc4
- Linux / Linux kernellinux-5.12.y – v5.12.4
- Linux / Linux kernellinux-5.11.y – v5.11.21
- Linux / Linux kernellinux-5.10.y – v5.10.37
- Linux / Linux kernelv5.8 – 5.8*
References
- MAILING_LISThttps://www.openwall.com/lists/oss-security/2021/05/11/10
- MISChttps://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=4b81ccebaeee885ab1aa1438133f2991e3a2b6ea
- VENDOR_ADVISORYhttps://www.zerodayinitiative.com/advisories/ZDI-21-590/
- VENDOR_ADVISORYhttps://ubuntu.com/security/notices/USN-4950-1
- VENDOR_ADVISORYhttps://ubuntu.com/security/notices/USN-4949-1
- MISChttps://security.netapp.com/advisory/ntap-20210716-0004/