High 7.8Published Dec 6, 2025

CVE-2025-40269ALSA: usb-audio: Fix potential overflow of PCM transfer buffer

Updated under an hour ago (Oct 27, 2026, 2:50 PM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Fix potential overflow of PCM transfer buffer The PCM stream data in USB-audio driver is transferred over USB URB packet buffers, and each packet size is determined dynamically. The packet sizes are limited by some factors such as wMaxPacketSize USB descriptor. OTOH, in the current code, the actually used packet sizes are determined only by the rate and the PPS, which may be bigger than the size limit above. This results in a buffer overflow, as reported by syzbot. Basically when the limit is smaller than the calculated packet size, it implies that something is wrong, most likely a weird USB descriptor. So the best option would be just to return an error at the parameter setup time before doing any further operations. This patch introduces such a sanity check, and returns -EINVAL when the packet size is greater than maxpacksize. The comparison with ep->packsize[1] alone should suffice since it's always equal or greater than ep->packsize[0].

CVSS: 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Deferred
Record last updated: Aug 5, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 02c56650f3c118d3752122996d96173d26bb13aa before 480a1490c595a242f27493a4544b3efb21b29f6a; from 5ef30e443e6d3654cccecec99cf481a69a0a6d3b before ab0b5e92fc36ee82c1bd01fe896d0f775ed5de41; 99703c921864a318e3e8aae74fde071b1ff35bea builds before 282aba56713bbc58155716b55ca7222b2d9cf3c8; from 2d50acd7dbd0682a56968ad9551341d7fc5b6eaf before c4dc012b027c9eb101583011089dea14d744e314; from aba41867dd66939d336fdf604e4d73b805d8039f before e0ed5a36fb3ab9e7b9ee45cd17f09f6d5f594360; from d288dc74f8cf95cb7ae0aaf245b7128627a49bf3 before d67dde02049e632ba58d3c44a164a74b6a737154; from f0bd62b64016508938df9babe47f65c2c727d25c before 6a5da3fa80affc948923f20a4e086177f505e86e; from f0bd62b64016508938df9babe47f65c2c727d25c before 217d47255a2ec8b246f2725f5db9ac3f1d4109d7; and 11 more ranges	CNA record

References

References

https://git.kernel.org/stable/c/480a1490c595a242f27493a4544b3efb21b29f6a
https://git.kernel.org/stable/c/ab0b5e92fc36ee82c1bd01fe896d0f775ed5de41
https://git.kernel.org/stable/c/282aba56713bbc58155716b55ca7222b2d9cf3c8
https://git.kernel.org/stable/c/c4dc012b027c9eb101583011089dea14d744e314
https://git.kernel.org/stable/c/e0ed5a36fb3ab9e7b9ee45cd17f09f6d5f594360
https://git.kernel.org/stable/c/d67dde02049e632ba58d3c44a164a74b6a737154
https://git.kernel.org/stable/c/6a5da3fa80affc948923f20a4e086177f505e86e
https://git.kernel.org/stable/c/217d47255a2ec8b246f2725f5db9ac3f1d4109d7
https://git.kernel.org/stable/c/ef592bf2232a2daa9fffa8881881fc9957ea56e9
https://git.kernel.org/stable/c/ece3b981bb6620e47fac826a2156c090b1a936a0
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The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.