In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Fix DMA buffer out-of-bounds write when fill_max is set When a USB audio endpoint requests full packet transfers via the fill_max descriptor flag, data_ep_set_params() promotes ep->curpacksize to ep->maxpacksize. However, maxsize is left at the original sample-rate derived value. Since u->buffer_size is allocated as maxsize * packets, the resulting DMA buffer is far too small for the requested transfer length. When the USB host controller streams up to curpacksize bytes per packet, it writes past the end of the buffer via DMA, corrupting kernel heap memory. Update maxsize to curpacksize when fill_max is set so that the allocated DMA buffer size matches the actual transfer request size. [ changed to reassign maxsize only when ep->fill_max is set -- tiwai ]
History

Sat, 15 Aug 2026 16:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-122
CWE-787

Sat, 15 Aug 2026 12:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Fix DMA buffer out-of-bounds write when fill_max is set When a USB audio endpoint requests full packet transfers via the fill_max descriptor flag, data_ep_set_params() promotes ep->curpacksize to ep->maxpacksize. However, maxsize is left at the original sample-rate derived value. Since u->buffer_size is allocated as maxsize * packets, the resulting DMA buffer is far too small for the requested transfer length. When the USB host controller streams up to curpacksize bytes per packet, it writes past the end of the buffer via DMA, corrupting kernel heap memory. Update maxsize to curpacksize when fill_max is set so that the allocated DMA buffer size matches the actual transfer request size. [ changed to reassign maxsize only when ep->fill_max is set -- tiwai ]
Title ALSA: usb-audio: Fix DMA buffer out-of-bounds write when fill_max is set
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-15T12:27:25.123Z

Reserved: 2026-08-15T05:44:03.907Z

Link: CVE-2026-74498

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-15T13:17:54.760

Modified: 2026-08-15T13:17:54.760

Link: CVE-2026-74498

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-15T16:00:07Z