CVE-2023-53445
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-09-18

Last updated on: 2025-12-12

Assigner: kernel.org

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.
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Meta Information
Published
2025-09-18
Last Modified
2025-12-12
Generated
2026-06-16
AI Q&A
2025-09-18
EPSS Evaluated
2026-06-14
NVD
CVE-2023-53445
Affected Vendors & Products
Showing 9 associated CPEs
Vendor Product Version / Range
linux linux_kernel From 5.6 (inc) to 5.10.178 (exc)
linux linux_kernel From 5.11 (inc) to 5.15.107 (exc)
linux linux_kernel From 5.16 (inc) to 6.1.24 (exc)
linux linux_kernel From 6.2 (inc) to 6.2.11 (exc)
linux linux_kernel 6.3
linux linux_kernel 6.3
linux linux_kernel 6.3
linux linux_kernel 6.3
linux linux_kernel 6.3
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Executive Summary

This vulnerability is a reference count bug in the Linux kernel's qrtr_recvmsg() function. It involves a use-after-free condition caused by improper handling of reference counts in concurrent scenarios between qrtr_recvmsg() and qrtr_endpoint_unregister(). Specifically, the bug occurs when the reference count is incremented or decremented incorrectly, leading to potential access to freed memory.

Impact Analysis

The impact of this vulnerability could include system instability or crashes due to use-after-free errors in the kernel. This may lead to denial of service or potentially allow an attacker to execute arbitrary code or escalate privileges by exploiting the memory corruption.

Mitigation Strategies

The vulnerability is fixed by improving the protection of node references using qrtr_node_lock to protect qrtr_node_lookup() implementation. Immediate mitigation would involve updating the Linux kernel to a version that includes this fix to avoid the refcount use-after-free bug in qrtr_recvmsg().

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