{"id":"AZL-99621","summary":"CVE-2026-80829 affecting package kernel 6.6.150.1-1","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 &transfer_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     &transfer_buffer[2],\n\t\t\t\t     ep-\u003emax_transfer - 2);\n\nep-\u003emax_transfer comes from the output endpoint's 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.","modified":"2026-09-06T05:31:44Z","published":"2026-09-04T16:18:10Z","upstream":["CVE-2026-80829"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80829"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-99621.json"}}],"schema_version":"1.9.0"}