{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2023-53523 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2023-53523 is a medium-severity vulnerability in Linux kernel, published on 1 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2023-53523 and fix it if it is affected.\n\nWhat it is: CVE-2023-53523 is a medium-severity vulnerability in Linux kernel, published on 1 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2023-53523 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2023-53523/ (Markdown: https://insights.sbomify.com/CVE-2023-53523/index.md)","id":"CVE-2023-53523","markdown":"https://insights.sbomify.com/CVE-2023-53523/index.md","name":"CVE-2023-53523","record":{"aliases":["BELL-CVE-2023-53523","DEBIAN-CVE-2023-53523","GHSA-67pq-6gr2-gqmr","ROOT-OS-DEBIAN-12-CVE-2023-53523","UBUNTU-CVE-2023-53523"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel driver","requires_auth":"low_privilege","summary":"A race condition in the gs_usb CAN driver causes a null pointer dereference, leading to a kernel crash when unloading the driver.","user_interaction":"not_required","vuln_class":"null_dereference"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-476","name":"NULL Pointer Dereference"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncan: gs_usb: fix time stamp counter initialization\n\nIf the gs_usb device driver is unloaded (or unbound) before the\ninterface is shut down, the USB stack first calls the struct\nusb_driver::disconnect and then the struct net_device_ops::ndo_stop\ncallback.\n\nIn gs_usb_disconnect() all pending bulk URBs are killed, i.e. no more\nRX'ed CAN frames are send from the USB device to the host. Later in\ngs_can_close() a reset control message is send to each CAN channel to\nremove the controller from the CAN bus. In this race window the USB\ndevice can still receive CAN frames from the bus and internally queue\nthem to be send to the host.\n\nAt least in the current version of the candlelight firmware, the queue\nof received CAN frames is not emptied during the reset command. After\nloading (or binding) the gs_usb driver, new URBs are submitted during\nthe struct net_device_ops::ndo_open callback and the candlelight\nfirmware starts sending its already queued CAN frames to the host.\n\nHowever, this scenario was not considered when implementing the\nhardware timestamp function. The cycle counter/time counter\ninfrastructure is set up (gs_usb_timestamp_init()) after the USBs are\nsubmitted, resulting in a NULL pointer dereference if\ntimecounter_cyc2time() (via the call chain:\ngs_usb_receive_bulk_callback() -\u003e gs_usb_set_timestamp() -\u003e\ngs_usb_skb_set_timestamp()) is called too early.\n\nMove the gs_usb_timestamp_init() function before the URBs are\nsubmitted to fix this problem.\n\nFor a comprehensive solution, we need to consider gs_usb devices with\nmore than 1 channel. The cycle counter/time counter infrastructure is\nsetup per channel, but the RX URBs are per device. Once gs_can_open()\nof _a_ channel has been called, and URBs have been submitted, the\ngs_usb_receive_bulk_callback() can be called for _all_ available\nchannels, even for channels that are not running, yet. As cycle\ncounter/time counter has not set up, this will again lead to a NULL\npointer dereference.\n\nConvert the cycle counter/time counter from a \"per channel\" to a \"per\ndevice\" functionality. Also set it up, before submitting any URBs to\nthe device.\n\nFurther in gs_usb_receive_bulk_callback(), don't process any URBs for\nnot started CAN channels, only resubmit the URB.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"can: gs_usb: fix time stamp counter initialization","id":"CVE-2023-53523","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2023"},"n_packages":0,"n_references":2,"next":{"headline":"wifi: iwlwifi: pcie: Fix integer overflow in iwl_write_to_user_buf","id":"CVE-2023-53524"},"packages":[],"prev":{"headline":"cgroup,freezer: hold cpu_hotplug_lock before freezer_mutex","id":"CVE-2023-53522"},"products":["Linux"],"published":"2025-10-01","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A race condition in the gs_usb CAN driver causes a null pointer dereference, leading to a kernel crash when unloading the driver.","url":"https://insights.sbomify.com/CVE-2023-53523/"}