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/ab580a75-91c8-d68a-3455-40361be1bfa8@linux.alibaba.com/T/#t
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 02 Oct 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low


Wed, 01 Oct 2025 12:00:00 +0000

Type Values Removed Values Added
Description 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/ab580a75-91c8-d68a-3455-40361be1bfa8@linux.alibaba.com/T/#t
Title io_uring: fix fget leak when fs don't support nowait buffered read
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-10-01T11:46:00.185Z

Reserved: 2025-10-01T11:39:39.406Z

Link: CVE-2023-53511

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-10-01T12:15:55.030

Modified: 2025-10-01T12:15:55.030

Link: CVE-2023-53511

cve-icon Redhat

Severity : Low

Publid Date: 2025-10-01T00:00:00Z

Links: CVE-2023-53511 - Bugzilla

cve-icon OpenCVE Enrichment

No data.