CVE-2021-3491

 

Published at: - 04-06-2021 04:15

Last modified: - 26-10-2022 02:02

Total changes: - 5

Description

The io_uring subsystem in the Linux kernel allowed the MAX_RW_COUNT limit to be bypassed in the PROVIDE_BUFFERS operation, which led to negative values being usedin mem_rw when reading /proc/<PID>/mem. This could be used to create a heap overflow leading to arbitrary code execution in the kernel. It was addressed via commit d1f82808877b ("io_uring: truncate lengths larger than MAX_RW_COUNT on provide buffers") (v5.13-rc1) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced in ddf0322db79c ("io_uring: add IORING_OP_PROVIDE_BUFFERS") (v5.7-rc1).

Common Vulnerability Scoring System (CVSS)

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

 

Verification logic

 

Reference

• https://ubuntu.com/security/notices/USN-4949-1
• https://ubuntu.com/security/notices/USN-4950-1
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d1f82808877bb10d3deee7cf3374a4eb3fb582db
• https://www.zerodayinitiative.com/advisories/ZDI-21-589/
• [oss-security] CVE-2021-3491 - Linux kernel io_uring PROVIDE_BUFFERS MAX_RW_COUNT bypass-Mailing List, Patch, Third Party Advisory
• https://security.netapp.com/advisory/ntap-20210716-0004/

 

Keywords

NVD

 

CVE-2021-3491

 

CVE

 

Common vulnerabilities & exposures

 

CVSS

 

Common vulnerability scoring system

 

Security

 

Vulnerabilities

 

Exposures