CVE-2026-98769 PUBLISHED

usb: gadget: f_uac1_legacy: validate bRequest index in generic_{set,get}_cmd

Assigner: Linux
Reserved: 25.09.2026 Published: 18.10.2026 Updated: 18.10.2026

In the Linux kernel, the following vulnerability has been resolved:

usb: gadget: f_uac1_legacy: validate bRequest index in generic_{set,get}_cmd

generic_set_cmd() and generic_get_cmd() use the low nibble of ctrl->bRequest as an index into con->data[]:

<pre>u8 cmd = (ctrl->bRequest & 0x0F); /* 0 .. 15 */ ... con->data[cmd] = value; /* OOB when cmd >= 5 */ </pre>

struct usb_audio_control (include/linux/usb/audio.h) declares data as a 5-element array, so indices 5 through 15 write (or read) up to 44 bytes past the end of the array on the heap.

A malicious USB host can craft a class-specific SET_CUR / GET_CUR request with an arbitrary bRequest value, triggering the out-of-bounds access from an IRQ completion handler with no further preconditions.

Add an ARRAY_SIZE() guard to both functions.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from c47d7b09891abb4f8b222317c89c7469bed8db3a to 36f3f009049bc91e14dc856007932473318d12f8 (excl.)
  • affected from c47d7b09891abb4f8b222317c89c7469bed8db3a to 8c611876c002d712ae5f246af5188432c708f79d (excl.)
  • affected from c47d7b09891abb4f8b222317c89c7469bed8db3a to 697cfe6e53b66cda196d6f8833b0ee97fefd0a8a (excl.)
  • affected from c47d7b09891abb4f8b222317c89c7469bed8db3a to 9062d50e75c24dc7911be05c9b1719b3b256af15 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 2.6.31 is affected
  • unaffected from 0 to 2.6.31 (excl.)
  • unaffected from 6.12.113 to 6.12.* (incl.)
  • unaffected from 6.18.56 to 6.18.* (incl.)
  • unaffected from 7.2.10 to 7.2.* (incl.)
  • unaffected from 7.3-rc6 to * (incl.)

References