PT-2024-8916 · Linux+4 · Linux Kernel+4
Eric Biggers
+1
·
Published
2024-05-24
·
Updated
2025-01-21
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CVE-2021-47505
CVSS v3.1
7.8
High
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Name of the Vulnerable Software and Affected Versions:
Linux kernel versions prior to 4.18
Description:
The vulnerability is related to a use-after-free error in the Linux kernel's aio component. This error occurs when the
aio poll wake() function is called and the POLLFREE notification is not handled properly, allowing a use-after-free to occur if a signalfd or binder fd is polled with aio poll and the waitqueue gets freed. The issue is caused by the fact that aio poll does not handle POLLFREE notifications, unlike eventpoll. To fix this, a patch was applied to make aio poll handle POLLFREE in a deadlock-free way, taking advantage of the fact that freeing of the waitqueue is RCU-delayed.Recommendations:
To resolve the issue, update the Linux kernel to a version that includes the fix for the use-after-free error in the aio component. Specifically, update to a version later than 4.18.
Note: The provided input descriptions do not mention specific fixed versions or patchdays, so the recommendation is based on the information that the vulnerability was introduced in kernel v4.18.
Fix
Use After Free
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Weakness Enumeration
Related Identifiers
Affected Products
Astra Linux
Linux Kernel
Red Hat
Red Os
Suse