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 ]
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 21 Aug 2026 21:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-122

Thu, 20 Aug 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate


Wed, 19 Aug 2026 17:00:00 +0000


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

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-19T16:37:57.897Z

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: 2026-08-19T17:21:07.203

Link: CVE-2026-74498

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-08-15T00:00:00Z

Links: CVE-2026-74498 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-21T23:00:14Z

Weaknesses