{"cve":"CVE-2021-47231","nvd":{"published":"2024-05-21T15:15:12.477","modified":"2026-06-17T04:16:57.830","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncan: mcba_usb: fix memory leak in mcba_usb\n\nSyzbot reported memory leak in SocketCAN driver for Microchip CAN BUS\nAnalyzer Tool. The problem was in unfreed usb_coherent.\n\nIn mcba_usb_start() 20 coherent buffers are allocated and there is\nnothing, that frees them:\n\n1) In callback function the urb is resubmitted and that's all\n2) In disconnect function urbs are simply killed, but URB_FREE_BUFFER\n   is not set (see mcba_usb_start) and this flag cannot be used with\n   coherent buffers.\n\nFail log:\n| [ 1354.053291][ T8413] mcba_usb 1-1:0.0 can0: device disconnected\n| [ 1367.059384][ T8420] kmemleak: 20 new suspected memory leaks (see /sys/kernel/debug/kmem)\n\nSo, all allocated buffers should be freed with usb_free_coherent()\nexplicitly\n\nNOTE:\nThe same pattern for allocating and freeing coherent buffers\nis used in drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-401"],"references":["https://git.kernel.org/stable/c/6bd3d80d1f019cefa7011056c54b323f1d8b8e83","https://git.kernel.org/stable/c/6f87c0e21ad20dd3d22108e33db1c552dfa352a0","https://git.kernel.org/stable/c/89df95ce32be204eef2e7d4b2f6fb552fb191a68","https://git.kernel.org/stable/c/91c02557174be7f72e46ed7311e3bea1939840b0","https://git.kernel.org/stable/c/a115198caaab6d663bef75823a3c5f0802306d60"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2021-47231","score":0.00226,"percentile":0.13356,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}