ALSA: usb-audio: Prevent excessive number of frames

Summary

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

Timeline

1. Feb 14, 2026, 4:27 PM UTCCVE published
2. Oct 30, 2026, 12:23 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 4.4.229 · fixed in 4.4.230; From 4.9.229 · fixed in 4.9.230; From 4.14.186 · fixed in 4.14.188; From 4.19.130 · fixed in 4.19.132; From 5.4.49 · fixed in 5.4.51; From 5.7.6 · fixed in 5.7.8

• Linux Linux

  5.8

• KernelLinux

  fixed in 4.4.230; From 4.5.0 · fixed in 4.9.230; From 4.10.0 · fixed in 4.14.188; From 4.15.0 · fixed in 4.19.132; From 4.20.0 · fixed in 5.4.51; From 5.5.0 · fixed in 5.7.8; From 5.8.0 · fixed in 6.6.160; fixed in 6.12.114; From 6.7.0 · fixed in 6.18.10

References 11