CVE-2026-23208

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

ALSA: usb-audio: Prevent excessive number of frames

In this case, the user constructed the parameters with maxpacksize 40

for rate 22050 / pps 1000, and packsize[0] 22 packsize[1] 23. The buffer

size for each data URB is maxpacksize * packets, which in this example

is 40 * 6 = 240; When the user performs a write operation to send audio

data into the ALSA PCM playback stream, the calculated number of frames

is packsize[0] * packets = 264, which exceeds the allocated URB buffer

size, triggering the out-of-bounds (OOB) issue reported by syzbot [1].

Added a check for the number of single data URB frames when calculating

the number of frames to prevent [1].

[1]

BUG: KASAN: slab-out-of-bounds in copy_to_urb+0x261/0x460 sound/usb/pcm.c:1487

Write of size 264 at addr ffff88804337e800 by task syz.0.17/5506

Call Trace:

copy_to_urb+0x261/0x460 sound/usb/pcm.c:1487

prepare_playback_urb+0x953/0x13d0 sound/usb/pcm.c:1611

prepare_outbound_urb+0x377/0xc50 sound/usb/endpoint.c:333