{"id":"CVE-2026-80971","title":"ALSA: bcd2000: clear the URB pointers on disconnect","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: bcd2000: clear the URB pointers on disconnect\n\nbcd2000_free_usb_related_resources() frees both URBs and leaves the\npointers behind:\n\n\tusb_kill_urb(bcd2k->midi_out…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-825"],"vendor":"Linux","product":"Linux","affected":["Linux >= b47a22290d581277be70e8a597824a4985d39e83 < 9af08677aa57debaca5b57c8045c52a83d3dd376","Linux >= b47a22290d581277be70e8a597824a4985d39e83 < 5a77febac6faf6da40fbb4555f703eeb91b58130","Linux >= b47a22290d581277be70e8a597824a4985d39e83 < 3c00004f134fc819f9d9e202c6a64acde0a1f8d0","Linux >= b47a22290d581277be70e8a597824a4985d39e83 < 6c07aad8a7c9ef8ebc4d03a964b882123a349a2e","Linux >= b47a22290d581277be70e8a597824a4985d39e83 < eb482a06791d6168beb8c78cc904ac5a5ed96a55","Linux >= b47a22290d581277be70e8a597824a4985d39e83 < 7df3194bdb7479cad9199889655a566a2c0c1d1b","Linux >= b47a22290d581277be70e8a597824a4985d39e83 < b06ebc7fe25a6af4a9f6e4a3d4236a4178ad4b01","Linux >= b47a22290d581277be70e8a597824a4985d39e83 < 459d3a64766f5ca2f1886daeaf24582831a5f5ab","Linux 3.16"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T19:21:35.341329Z"},"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:45:55.974Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80971","references":[{"url":"https://git.kernel.org/stable/c/9af08677aa57debaca5b57c8045c52a83d3dd376"},{"url":"https://git.kernel.org/stable/c/5a77febac6faf6da40fbb4555f703eeb91b58130"},{"url":"https://git.kernel.org/stable/c/3c00004f134fc819f9d9e202c6a64acde0a1f8d0"},{"url":"https://git.kernel.org/stable/c/6c07aad8a7c9ef8ebc4d03a964b882123a349a2e"},{"url":"https://git.kernel.org/stable/c/eb482a06791d6168beb8c78cc904ac5a5ed96a55"},{"url":"https://git.kernel.org/stable/c/7df3194bdb7479cad9199889655a566a2c0c1d1b"},{"url":"https://git.kernel.org/stable/c/b06ebc7fe25a6af4a9f6e4a3d4236a4178ad4b01"},{"url":"https://git.kernel.org/stable/c/459d3a64766f5ca2f1886daeaf24582831a5f5ab"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80971.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-80971"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532082"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80971"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80971"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80971.mbox"}],"tags":["cve.org","csaf","vex","red-hat"],"epss":0.00164,"epssPercentile":0.05555,"scores":{"cna":7.8,"vendor":7},"ingestedAt":"2026-09-14T15:23:07.455Z","slug":"CVE-2026-80971","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nALSA: bcd2000: clear the URB pointers on disconnect\n\nbcd2000_free_usb_related_resources() frees both URBs and leaves the\npointers behind:\n\n\tusb_kill_urb(bcd2k->midi_out_urb);\n\tusb_kill_urb(bcd2k->midi_in_urb);\n\n\tusb_free_urb(bcd2k->midi_out_urb);\n\tusb_free_urb(bcd2k->midi_in_urb);\n\nThe rawmidi device outlives that call.  A substream that is still open\nwhen the device is unplugged reaches bcd2000_midi_send() from the\ntrigger path on close.  That function writes to the freed URB and then\nhands it to the USB core:\n\n\tbcd2k->midi_out_urb->transfer_buffer_length = BUFSIZE;\n\t...\n\tret = usb_submit_urb(bcd2k->midi_out_urb, GFP_ATOMIC);\n\nusb_kill_urb() does not stop a later submission either, so a submit that\nraces the disconnect can requeue the URB after it has been reaped.\nmidi_in_urb is exposed the same way: bcd2000_input_complete() resubmits\nit from the completion handler.\n\nKASAN on 7.2.0-rc5 (arm64):\n\n  BUG: KASAN: slab-use-after-free in bcd2000_midi_send [snd_bcd2000]\n  Write of size 4 at addr ffff00001827d388 by task bpoc/168\n   __asan_store4\n   bcd2000_midi_send [snd_bcd2000]\n   bcd2000_midi_output_trigger [snd_bcd2000]\n   snd_rawmidi_kernel_write1\n   close_substream.part.0\n  Freed by task 168:\n   usb_free_urb\n   bcd2000_disconnect [snd_bcd2000]\n\n  BUG: KASAN: slab-use-after-free in usb_submit_urb\n  Read of size 8 at addr ffff00001827d3b8 by task bpoc/168\n\nClear both pointers after freeing and test them on the paths that can\nstill run.  Poison the URBs before freeing them: usb_poison_urb() waits\nfor a running completion handler and rejects any later submission, so\nafter it returns the input path is quiesced and only the rawmidi trigger\npath can still reach bcd2000_midi_send().  No unpoison is needed; the\nURBs are freed on the next line.\n\nDiscovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>\n\n## Affected\n\n- `Linux >= b47a22290d581277be70e8a597824a4985d39e83 < 9af08677aa57debaca5b57c8045c52a83d3dd376`\n- `Linux >= b47a22290d581277be70e8a597824a4985d39e83 < 5a77febac6faf6da40fbb4555f703eeb91b58130`\n- `Linux >= b47a22290d581277be70e8a597824a4985d39e83 < 3c00004f134fc819f9d9e202c6a64acde0a1f8d0`\n- `Linux >= b47a22290d581277be70e8a597824a4985d39e83 < 6c07aad8a7c9ef8ebc4d03a964b882123a349a2e`\n- `Linux >= b47a22290d581277be70e8a597824a4985d39e83 < eb482a06791d6168beb8c78cc904ac5a5ed96a55`\n- `Linux >= b47a22290d581277be70e8a597824a4985d39e83 < 7df3194bdb7479cad9199889655a566a2c0c1d1b`\n- `Linux >= b47a22290d581277be70e8a597824a4985d39e83 < b06ebc7fe25a6af4a9f6e4a3d4236a4178ad4b01`\n- `Linux >= b47a22290d581277be70e8a597824a4985d39e83 < 459d3a64766f5ca2f1886daeaf24582831a5f5ab`\n- `Linux 3.16`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80971.json)","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":223334,"id":"CVE-2026-80971","ts":1792180061500,"field":"cvss","old":"7","new":"7.8"},{"seq":204195,"id":"CVE-2026-80971","ts":1789490240107,"field":"cvss","old":"7.8","new":"7"},{"seq":183600,"id":"CVE-2026-80971","ts":1789356676053,"field":"cvss","old":"7.8","new":"4.4"},{"seq":183599,"id":"CVE-2026-80971","ts":1789356676053,"field":"severity","old":"high","new":"medium"},{"seq":153152,"id":"CVE-2026-80971","ts":1789285349306,"field":"cvss","old":null,"new":"7.8"},{"seq":153151,"id":"CVE-2026-80971","ts":1789285349306,"field":"severity","old":"none","new":"high"},{"seq":109580,"id":"CVE-2026-80971","ts":1789183732495,"field":"cvss","old":null,"new":"4.4"},{"seq":109579,"id":"CVE-2026-80971","ts":1789183732495,"field":"severity","old":"none","new":"medium"}]}