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🛡️ CVE-2023-53445 — kernel

🟠 CVSS 7.8 — High ✅ No Known Exploit NVD
7.8
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

net: qrtr: Fix a refcount bug in qrtr_recvmsg()

In the Linux kernel, the following vulnerability has been resolved:

net: qrtr: Fix a refcount bug in qrtr_recvmsg()

Syzbot reported a bug as following:

refcount_t: addition on 0; use-after-free.

...

RIP: 0010:refcount_warn_saturate+0x17c/0x1f0 lib/refcount.c:25

...

Call Trace:

<TASK>

__refcount_add include/linux/refcount.h:199 [inline]

__refcount_inc include/linux/refcount.h:250 [inline]

refcount_inc include/linux/refcount.h:267 [inline]

kref_get include/linux/kref.h:45 [inline]

qrtr_node_acquire net/qrtr/af_qrtr.c:202 [inline]

qrtr_node_lookup net/qrtr/af_qrtr.c:398 [inline]

qrtr_send_resume_tx net/qrtr/af_qrtr.c:1003 [inline]

qrtr_recvmsg+0x85f/0x990 net/qrtr/af_qrtr.c:1070

sock_recvmsg_nosec net/socket.c:1017 [inline]

sock_recvmsg+0xe2/0x160 net/socket.c:1038

qrtr_ns_worker+0x170/0x1700 net/qrtr/ns.c:688

process_one_work+0x991/0x15c0 kernel/workqueue.c:2390

worker_thread+0x669/0x1090 kernel/workqueue.c:2537

It occurs in the concurrent scenario of qrtr_recvmsg() and

qrtr_endpoint_unregister() as following:

cpu0 cpu1

qrtr_recvmsg qrtr_endpoint_unregister

qrtr_send_resume_tx qrtr_node_release

qrtr_node_lookup mutex_lock(&qrtr_node_lock)

spin_lock_irqsave(&qrtr_nodes_lock, ) refcount_dec_and_test(&node->ref) [node->ref == 0]

radix_tree_lookup [node != NULL] __qrtr_node_release

qrtr_node_acquire spin_lock_irqsave(&qrtr_nodes_lock, )

kref_get(&node->ref) [WARNING] ...

mutex_unlock(&qrtr_node_lock)

Use qrtr_node_lock to protect qrtr_node_lookup() implementation, this

is actually improving the protection of node reference.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Local — a local account, shell or session on the host is needed.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: Low — an ordinary user account is enough.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: High — total loss, or loss the attacker controls.
  • Availability impact: High — total loss, or loss the attacker controls.

Affected software

CVE-2023-53445 is recorded against 2 packages.

  • kernel (from 6.2.0 up to 6.2.11)
  • linux-kernel

Timeline and source

Published on 18 September 2025 and last revised on 12 August 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
github.com (Advisory)
nvd.nist.gov (Advisory)
git.kernel.org (Package)

Other advisories for this package

kernel has other advisories on record. If you are patching this one, these are worth checking on the same host:

CVE-2023-53445 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity High
CVSS Score 7.8
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE N/A
Public Exploit ✅ No
Source NVD
Published 2025-09-18
Updated 2026-08-20
Modified 2026-08-12

Affected Packages

Software From version Fixed in
kernel 6.2.0 6.2.11
linux-kernel — —

Similar Threats

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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