CVEvulnerability
CVE-2021-47231
5.5 MEDIUM
Official page ↗
- Status
- Analyzed
- Published
- 2024-05-21
- Last modified
- 2026-06-17
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 (134c704f-9b21-4f2e-91b3-4a467353bcc0)
- 5.5 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-401
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
Affected configurations
• linux linux kernel (>= 4.12 < 4.14.238)
• linux linux kernel (>= 4.15 < 4.19.196)
• linux linux kernel (>= 4.20 < 5.4.128)
• linux linux kernel (>= 5.5 < 5.10.46)
• linux linux kernel (>= 5.11 < 5.12.13)
• linux linux kernel 5.13
Related
Weakness · CWE (1)
- CWE-401 Missing Release of Memory after Effective Lifetime weakness
References
- https://git.kernel.org/stable/c/6bd3d80d1f019cefa7011056c54b323f1d8b8e83 Patch
- https://git.kernel.org/stable/c/6f87c0e21ad20dd3d22108e33db1c552dfa352a0 Patch
- https://git.kernel.org/stable/c/89df95ce32be204eef2e7d4b2f6fb552fb191a68 Patch
- https://git.kernel.org/stable/c/91c02557174be7f72e46ed7311e3bea1939840b0 Patch
- https://git.kernel.org/stable/c/a115198caaab6d663bef75823a3c5f0802306d60 Patch
- https://git.kernel.org/stable/c/d0760a4ef85697bc756d06eae17ae27f3f055401 Patch
- https://git.kernel.org/stable/c/6bd3d80d1f019cefa7011056c54b323f1d8b8e83 Patch
- https://git.kernel.org/stable/c/6f87c0e21ad20dd3d22108e33db1c552dfa352a0 Patch
- https://git.kernel.org/stable/c/89df95ce32be204eef2e7d4b2f6fb552fb191a68 Patch
- https://git.kernel.org/stable/c/91c02557174be7f72e46ed7311e3bea1939840b0 Patch
- https://git.kernel.org/stable/c/a115198caaab6d663bef75823a3c5f0802306d60 Patch
- https://git.kernel.org/stable/c/d0760a4ef85697bc756d06eae17ae27f3f055401 Patch