CVE-2023-53445

CVE-2023-53445 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

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.

Frequently asked questions

What is CVE-2023-53445?
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 severe is CVE-2023-53445?
CVE-2023-53445 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2023-53445 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-53445?
CVE-2023-53445 primarily affects Linux Linux Kernel. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-53445?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2023-53445 have an EU (EUVD) identifier?
Yes. CVE-2023-53445 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-29873.
When was CVE-2023-53445 published?
CVE-2023-53445 was published on 2025-09-18 and last updated on 2026-06-17.

References

Affected products (6)

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