CVE-2026-98769usb: gadget: f_uac1_legacy: validate bRequest index in generic_{set,get}_cmd

Official description

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

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/3e655ebe0e45b7b026a4d3e6c10586b95164b3fd
• https://git.kernel.org/stable/c/f8a4ddc23056560dc3333839a4c6998f644db303
• https://git.kernel.org/stable/c/f0ff630d83c12c9a97637dded1dc27558bee3760
• https://git.kernel.org/stable/c/da841c1511a6160b8bc6bb7b7c6d4c9fb76fb51e
• https://git.kernel.org/stable/c/36f3f009049bc91e14dc856007932473318d12f8
• https://git.kernel.org/stable/c/8c611876c002d712ae5f246af5188432c708f79d
• https://git.kernel.org/stable/c/697cfe6e53b66cda196d6f8833b0ee97fefd0a8a
• https://git.kernel.org/stable/c/9062d50e75c24dc7911be05c9b1719b3b256af15