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medium5.5

CVE-2021-47231

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 …

Impact

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

Affected products

VendorProductAffected versions
LinuxLinux Kernel
from 4.12 before 4.14.238
from 4.15 before 4.19.196
from 4.20 before 5.4.128
from 5.5 before 5.10.46
from 5.11 before 5.12.13
Version 5.13

Weakness classification

CWE-401

References