GHSA-VX4G-2353-JV9W
Vulnerability from github – Published: 2026-09-04 18:31 – Updated: 2026-09-04 18:31In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: fix OOB write in snd_usbmidi_novation_output()
snd_usbmidi_novation_output() lays out a two-byte header at transfer_buffer[0..1] and passes &transfer_buffer[2] together with a length of ep->max_transfer - 2 to snd_rawmidi_transmit():
count = snd_rawmidi_transmit(ep->ports[0].substream,
&transfer_buffer[2],
ep->max_transfer - 2);
ep->max_transfer comes from the output endpoint's wMaxPacketSize via usb_maxpacket(). A malformed or malicious device can advertise a bulk OUT endpoint with a wMaxPacketSize of 1 - the USB core only clamps this value downwards - so ep->max_transfer becomes 1 and the count argument becomes -1.
snd_rawmidi_transmit() passes the negative count on to __snd_rawmidi_transmit_peek(), where "if (count1 > count) count1 = count" leaves count1 negative; get_aligned_size() keeps it negative for a byte-stream substream, so the following memcpy(buffer, ..., count1) runs with a (size_t)-1 length and writes far past the transfer buffer, which was allocated with usb_alloc_coherent(ep->max_transfer).
This is the same class of bug that was fixed for snd_usbmidi_akai_output() in commit 0970274613fb ("ALSA: usb-audio: fix OOB write in snd_usbmidi_akai_output()"); the novation output routine was left unguarded. Bail out when the endpoint cannot hold the two-byte header plus at least one payload byte.
{
"affected": [],
"aliases": [
"CVE-2026-80829"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-04T16:18:10Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: usb-audio: fix OOB write in snd_usbmidi_novation_output()\n\nsnd_usbmidi_novation_output() lays out a two-byte header at\ntransfer_buffer[0..1] and passes \u0026transfer_buffer[2] together with a\nlength of ep-\u003emax_transfer - 2 to snd_rawmidi_transmit():\n\n\tcount = snd_rawmidi_transmit(ep-\u003eports[0].substream,\n\t\t\t\t \u0026transfer_buffer[2],\n\t\t\t\t ep-\u003emax_transfer - 2);\n\nep-\u003emax_transfer comes from the output endpoint\u0027s wMaxPacketSize via\nusb_maxpacket(). A malformed or malicious device can advertise a bulk\nOUT endpoint with a wMaxPacketSize of 1 - the USB core only clamps this\nvalue downwards - so ep-\u003emax_transfer becomes 1 and the count argument\nbecomes -1.\n\nsnd_rawmidi_transmit() passes the negative count on to\n__snd_rawmidi_transmit_peek(), where \"if (count1 \u003e count) count1 = count\"\nleaves count1 negative; get_aligned_size() keeps it negative for a\nbyte-stream substream, so the following memcpy(buffer, ..., count1) runs\nwith a (size_t)-1 length and writes far past the transfer buffer, which\nwas allocated with usb_alloc_coherent(ep-\u003emax_transfer).\n\nThis is the same class of bug that was fixed for snd_usbmidi_akai_output()\nin commit 0970274613fb (\"ALSA: usb-audio: fix OOB write in\nsnd_usbmidi_akai_output()\"); the novation output routine was left\nunguarded. Bail out when the endpoint cannot hold the two-byte header\nplus at least one payload byte.",
"id": "GHSA-vx4g-2353-jv9w",
"modified": "2026-09-04T18:31:28Z",
"published": "2026-09-04T18:31:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80829"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1035a8f63bae28e498b0e7b5ac91d749844a7158"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1074c2306901b44ebcb83855583c6776e1e392ea"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/558fc4485ecc704edfe7876d6cebae4738ff7ef8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7639ec9755d3ec0ec8cd7c0fdd2c3d3997434870"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7f00dbddb51f4f74325cdc7c3f6b19fb3392481a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/91919b3b99ab7ce3d7dbb39fcf7c6c742a663c0c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/94e4562fcc81badd1d467ddfb88c27e4fae974c2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9c8212436631b0063cb021e9f58df438e3db84d0"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e9c00d7533f99aa9833c4b598f47e3b3202fdb9a"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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