CVE-2021-47231

can: mcba_usb: fix memory leak in mcba_usb

Description

In the Linux kernel, the following vulnerability has been resolved: can: mcba_usb: fix memory leak in mcba_usb Syzbot reported memory leak in SocketCAN driver for Microchip CAN BUS Analyzer Tool. The problem was in unfreed usb_coherent. In mcba_usb_start() 20 coherent buffers are allocated and there is nothing, that frees them: 1) In callback function the urb is resubmitted and that's all 2) In disconnect function urbs are simply killed, but URB_FREE_BUFFER is not set (see mcba_usb_start) and this flag cannot be used with coherent buffers. Fail log: | [ 1354.053291][ T8413] mcba_usb 1-1:0.0 can0: device disconnected | [ 1367.059384][ T8420] kmemleak: 20 new suspected memory leaks (see /sys/kernel/debug/kmem) So, all allocated buffers should be freed with usb_free_coherent() explicitly NOTE: The same pattern for allocating and freeing coherent buffers is used in drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c

Category

5.5
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.04%
Affected: Linux Linux
Affected: Linux Linux
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2021-47231?
CVE-2021-47231 has been scored as a medium severity vulnerability.
How to fix CVE-2021-47231?
To fix CVE-2021-47231, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-47231 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-47231 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-47231?
CVE-2021-47231 affects Linux Linux, Linux Linux.
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