Bug 2036100 (CVE-2021-39685) - CVE-2021-39685 kernel: USB gadget buffer overflow
Summary: CVE-2021-39685 kernel: USB gadget buffer overflow
Alias: CVE-2021-39685
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 2036101
Blocks: Embargoed2036102
TreeView+ depends on / blocked
Reported: 2021-12-29 17:55 UTC by Guilherme de Almeida Suckevicz
Modified: 2022-01-05 19:39 UTC (History)
47 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
An out of bounds memory access flaw in the Linux kernel's USB Peripheral Controller functionality was found in the way users call control request handlers in a specific way for the USB gadget. A local user could use this flaw to crash the system or escalate their privileges on the system.
Clone Of:
Last Closed: 2021-12-30 08:48:44 UTC

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Description Guilherme de Almeida Suckevicz 2021-12-29 17:55:15 UTC
An attacker can access kernel memory bypassing valid buffer boundaries by exploiting implementation of control request handlers in the following usb gadgets - rndis, hid, uac1, uac1_legacy and uac2. Processing of malicious control transfer requests with unexpectedly large wLength lacks assurance that this value does not exceed the buffer size. Due to this fact one is capable of reading and/or writing (depending on particular case) up to 65k of kernel memory.


Comment 1 Guilherme de Almeida Suckevicz 2021-12-29 17:56:58 UTC
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2036101]

Comment 5 Justin M. Forbes 2022-01-05 13:40:29 UTC
This was fixed for Fedora with the 5.15.8 stable kernel update.

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