CVE-2023-53511

Medium

In the Linux kernel, the following vulnerability has been resolved: io_uring: fix fget leak when fs don't support nowait buffered read Heming reported a BUG when using io_uring doing link-cp on ocfs2. [1] Do the following steps can reproduce this BUG: mount -t ocfs2 /dev/vdc /mnt/ocfs2 cp testfile /mnt/ocfs2/ ./link-cp /mnt/ocfs2/testfile /mnt/ocfs2/testfile.1 umount /mnt/ocfs2 Then umount will fail, and it outputs: umount: /mnt/ocfs2: target is busy. While tracing umount, it blames mnt_get_count() not return as expected. Do a deep investigation for fget()/fput() on related code flow, I've finally found that fget() leaks since ocfs2 doesn't support nowait buffered read. io_issue_sqe |-io_assign_file // do fget() first |-io_read |-io_iter_do_read |-ocfs2_file_read_iter // return -EOPNOTSUPP |-kiocb_done |-io_rw_done |-__io_complete_rw_common // set REQ_F_REISSUE |-io_resubmit_prep |-io_req_prep_async // override req->file, leak happens This was introduced by commit a196c78b5443 in v5.18. Fix it by don't re-assign req->file if it has already been assigned. [1] https://lore.kernel.org/ocfs2-devel/[email protected]/T/#t

Package Linux Kernel
Published 2025-10-01
Last modified 2026-04-06
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-401

CVE-2023-53511 is a Memory Leak vulnerability

What is Memory Leak?

The product does not release memory after use, causing gradual resource exhaustion. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.17.9, 5.18 and later are affected. Fixed in 6.1.16, 6.2.3, 6.3 and their respective stable series.

Affected from
≥ 5.17.9 ≥ 5.18
Fixed in
✓ 6.1.16 6.1.x ✓ 6.2.3 6.2.x ✓ 6.3

References

The following references provide additional information about CVE-2023-53511 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2023-53511?

    CVE-2023-53511 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a Memory Leak flaw (CWE-401) . It affects Linux kernel versions from 5.17.9 onward and has been patched in 6.1.16, 6.2.3 and 6.3. CVE-2023-53511 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2023-53511?

    CVE-2023-53511 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2023-53511?

    Yes — CVE-2023-53511 has been patched. Fixed versions include 6.1.16, 6.2.3 and 6.3. If you are running Linux kernel 5.17.9 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2023-53511 actively exploited?

    No — CVE-2023-53511 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Memory Leak (CWE-401)?

    The product does not release memory after use, causing gradual resource exhaustion. View CWE-401 on MITRE CWE →

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