CVE-2021-47505
kernel: aio: fix use-after-free due to missing POLLFREE handling
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · May 24, 2024
Updated · October 21, 2026
Description
A flaw was found in the Linux kernel AIO poll path. It does not handle POLLFREE, so a file can be released while AIO still uses it. A local user can trigger a use-after-free and crash the kernel.
Statement
Following issue marked as moderate with "not affected" for Red Hat Enterprise Linux, as it is not vulnerable to this CVE. This is because the CVE does not impact the versions or configurations of the Linux kernel used in Red Hat's distributions. Additionally, some RHEL versions may be marked as "will not fix" due to the minimal impact of the issue, and no fix will be provided.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 6.6CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H
CWE-416 · Use After Free