CVE-2023-1583: A NULL pointer dereference was found in io_file_bitmap_get in io_uring/filetable.c in the io_uring sub-component in the Linux Kernel. When fixed files...

Description

A NULL pointer dereference was found in io_file_bitmap_get in io_uring/filetable.c in the io_uring sub-component in the Linux Kernel. When fixed files are unregistered, some context information (file_alloc_{start,end} and alloc_hint) is not cleared. A subsequent request that has auto index selection enabled via IORING_FILE_INDEX_ALLOC can cause a NULL pointer dereference. An unprivileged user can use the flaw to cause a system crash.

Metrics

CVSS 3.1

5.5/10

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

EPSS Probability

0.21%

11.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	>= 5.19, < 6.1.22
Linux	Linux Kernel	>= 6.2.0, < 6.2.9

References

Timeline

Published: Mar 24, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-1583?

A NULL pointer dereference was found in io_file_bitmap_get in io_uring/filetable.c in the io_uring sub-component in the Linux Kernel. When fixed files are unregistered, some context information (file_alloc_{start,end} and alloc_hint) is not cleared. A subsequent request that has auto index selection enabled via IORING_FILE_INDEX_ALLOC can cause a NULL pointer dereference. An unprivileged user can use the flaw to cause a system crash.

How severe is CVE-2023-1583?

CVE-2023-1583 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.

How do I fix CVE-2023-1583?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.