CVE-2020-29534: An issue was discovered in the Linux kernel before 5.9.3. io_uring takes a non-refcounted reference to the files_struct of the process that submitted a request causing execve() to incorrectly optimize unshare_fd() aka CID-0f2122045b94.

Overview

Severity

High (CVSS 7.8)

CVSS Vector

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

Exploit Status

Not Exploited

Patch Tuesday

2020-Dec

Released

2020-12-08

EPSS Score

0.04% (percentile: 12.2%)

FAQ

Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability? One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.

Affected Products (1)

Mariner

• cm1 kernel 5.4.91-1 on CBL Mariner 1.0

Revision History

• 2020-12-08: Information published.