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NVD / CVE Program· CNA Linux

CVE-2025-38453: io_uring/msg_ring: ensure io_kiocb freeing is deferred for RCU

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.18% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 094ba14a471cc6c68078c7ad488539eaf32c2277, e5b3432f4a6b418b8bd8fc91f38efbf17a77167a, fc582cd26e888b0652bc1494f252329453fd3b23.
  • Severity is disputed: the assigning authority (CNA) scores it 7.8, NVD 5.5.

Low priority for now. Upgrade to Linux Linux 094ba14a471cc6c68078c7ad488539eaf32c2277, e5b3432f4a6b418b8bd8fc91f38efbf17a77167a, fc582cd26e888b0652bc1494f252329453fd3b23 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: io_uring/msg_ring: ensure io_kiocb freeing is deferred for RCU syzbot reports that defer/local task_work adding via msg_ring can hit a request that has been freed: CPU: 1 UID: 0 PID: 19356 Comm: iou-wrk-19354 Not tainted 6.16.0-rc4-syzkaller-00108-g17bbde2e1716 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 io_req_local_work_add io_uring/io_uring.c:1184 [inline] __io_req_task_work_add+0x589/0x950 io_uring/io_uring.c:1252 io_msg_remote_post io_uring/msg_ring.c:103 [inline] io_msg_data_remote io_uring/msg_ring.c:133 [inline] __io_msg_ring_data+0x820/0xaa0 io_uring/msg_ring.c:151 io_msg_ring_data io_uring/msg_ring.c:173 [inline] io_msg_ring+0x134/0xa00 io_uring/msg_ring.c:314 __io_issue_sqe+0x17e/0x4b0 io_uring/io_uring.c:1739 io_issue_sqe+0x165/0xfd0 io_uring/io_uring.c:1762 io_wq_submit_work+0x6e9/0xb90 io_uring/io_uring.c:1874 io_worker_handle_work+0x7cd/0x1180 io_uring/io-wq.c:642 io_wq_worker+0x42f/0xeb0 io_uring/io-wq.c:696 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> which is supposed to be safe with how requests are allocated. But msg ring requests alloc and free on their own, and hence must defer freeing to a sane time. Add an rcu_head and use kfree_rcu() in both spots where requests are freed. Only the one in io_msg_tw_complete() is strictly required as it has been visible on the other ring, but use it consistently in the other spot as well. This should not cause any other issues outside of KASAN rightfully complaining about it.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Jul 25, 2025
Updated
Aug 5, 2026
EPSS
0.1% · 8th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CNA vs NVD score

NVD
5.5
CNA · Linux
7.8
2.3 point gap

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel6.11 and later · before 6.12.46
  • linux linux kernel6.13 and later · before 6.15.7
  • linux linux kernel6.16

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 6.11affected
    • 0617bb500bfabf8447062f1e1edde92ed2b638f1 and later · before 094ba14a471cc6c68078c7ad488539eaf32c2277affected · git
    • 0617bb500bfabf8447062f1e1edde92ed2b638f1 and later · before e5b3432f4a6b418b8bd8fc91f38efbf17a77167aaffected · git
    • 0617bb500bfabf8447062f1e1edde92ed2b638f1 and later · before fc582cd26e888b0652bc1494f252329453fd3b23affected · git
    • before 6.11not affected · semver
    • 6.12.46 and later · up to and including 6.12.*not affected · semver
    • 6.15.7 and later · up to and including 6.15.*not affected · semver
    • 6.16 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-124.31.1.el10_16.12.0-124.31.1.el10_1
AlmaLinux:10kernel-docbefore 6.12.0-124.31.1.el10_16.12.0-124.31.1.el10_1
Debian:13linuxbefore 6.12.48-16.12.48-1
Debian:14linuxbefore 6.16.3-16.16.3-1
Red Hat:enterprise_linux_eus:10.0kernelbefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64kbefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-corebefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debugbefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debug-corebefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debug-debuginfobefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debug-develbefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debug-devel-matchedbefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debug-modulesbefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debug-modules-corebefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debug-modules-extrabefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-debuginfobefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-develbefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-devel-matchedbefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-modulesbefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-modules-corebefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-64k-modules-extrabefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-abi-stablelistsbefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-corebefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0
Red Hat:enterprise_linux_eus:10.0kernel-debugbefore 0:6.12.0-55.58.1.el10_00:6.12.0-55.58.1.el10_0

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2025-38451Jul 25, 2025 · md/md-bitmap: fix GPF in bitmap_get_stats()
    22Monitor
  • ← EarlierCVE-2025-38452Jul 25, 2025 · net: ethernet: rtsn: Fix a null pointer dereference in rtsn_probe()
    22Monitor
  • Later →CVE-2025-38454Jul 25, 2025 · ALSA: ad1816a: Fix potential NULL pointer deref in snd_card_ad1816a_pnp()
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux094ba14a471cc6c68078c7ad488539eaf32c2277Vendor (CNA)
Linux Linuxe5b3432f4a6b418b8bd8fc91f38efbf17a77167aVendor (CNA)
Linux Linuxfc582cd26e888b0652bc1494f252329453fd3b23Vendor (CNA)
almalinux:kernel-abi-stablelists6.12.0-124.31.1.el10_1 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-doc6.12.0-124.31.1.el10_1 · AlmaLinux:10Package registry (OSV)
debian:linux6.12.48-1 · Debian:13Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-64k-debug-devel0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-64k-debug-devel-matched0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-64k-debuginfo0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-64k-devel0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-64k-devel-matched0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-debug-debuginfo0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-debug-devel0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-debug-devel-matched0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-debuginfo0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-debuginfo-common-aarch640:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
red hat:kernel-debuginfo-common-ppc64le0:6.12.0-124.31.1.el10_1 · Red Hat:enterprise_linux:10.1Package registry (OSV)
rocky linux:kernel0:6.12.0-124.31.1.el10_1 · Rocky Linux:10Package registry (OSV)
suse:kernel-livepatch-SLE15-SP7_Update_07-150700.3.18.1 · SUSE:Linux Enterprise Live Patching 15 SP7Package registry (OSV)
suse:kernel-livepatch-SLE15-SP7_Update_17-150700.2.1 · SUSE:Linux Enterprise Live Patching 15 SP7Package registry (OSV)
suse:kernel-livepatch-SLE15-SP7_Update_27-150700.4.1 · SUSE:Linux Enterprise Live Patching 15 SP7Package registry (OSV)
suse:kernel-livepatch-SLE15-SP7-RT_Update_07-150700.5.1 · SUSE:Linux Enterprise Live Patching 15 SP7Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records