CVE-2021-47231

Summary

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 Software

VendorProductVersion RangeStatus
LinuxLinux51f3baad7de943780ce0c17bd7975df567dd6e14 < 89df95ce32be204eef2e7d4b2f6fb552fb191a68affected
LinuxLinux51f3baad7de943780ce0c17bd7975df567dd6e14 < a115198caaab6d663bef75823a3c5f0802306d60affected
LinuxLinux51f3baad7de943780ce0c17bd7975df567dd6e14 < 6f87c0e21ad20dd3d22108e33db1c552dfa352a0affected
LinuxLinux51f3baad7de943780ce0c17bd7975df567dd6e14 < 6bd3d80d1f019cefa7011056c54b323f1d8b8e83affected
LinuxLinux51f3baad7de943780ce0c17bd7975df567dd6e14 < d0760a4ef85697bc756d06eae17ae27f3f055401affected
LinuxLinux51f3baad7de943780ce0c17bd7975df567dd6e14 < 91c02557174be7f72e46ed7311e3bea1939840b0affected
LinuxLinux4.12affected
LinuxLinux0 < 4.12unaffected
LinuxLinux4.14.238 <= 4.14.*unaffected
LinuxLinux4.19.196 <= 4.19.*unaffected
LinuxLinux5.4.128 <= 5.4.*unaffected
LinuxLinux5.10.46 <= 5.10.*unaffected
LinuxLinux5.12.13 <= 5.12.*unaffected
LinuxLinux5.13 <= *unaffected

Weaknesses

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References