{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80971","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-26T14:34:25.810Z","datePublished":"2026-09-11T19:42:34.441Z","dateUpdated":"2026-09-14T11:59:18.213Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-14T11:59:18.213Z"},"descriptions":[{"lang":"en","value":"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_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>"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The UAF is reached locally by USBDEVFS_DISCONNECT (or sysfs unbind) on an already-bound Behringer BCD2000 while /dev/snd/midi* is held, then close; there is no network or packet path. This matches AV:L scoring of analogous USB disconnect UAFs (CVE-2025-40283, CVE-2026-64585); physical unplug is only an extra path.\nAC:L - The attacker opens the rawmidi node, optionally enables active sensing, then issues USBDEVFS_DISCONNECT and close; close_substream deterministically writes the freed URB in bcd2000_midi_send(). Concurrent write versus disconnect is also attacker-driven. No uncontrollable race or layout is required to trigger the UAF.\nPR:L - USBDEVFS_DISCONNECT has no capable() check, only write access to /dev/bus/usb that udev uaccess/plugdev rules grant seat users, and snd_rawmidi_open has no capability gate on /dev/snd/midi*. An unprivileged local account suffices; init-namespace root is not required.\nUI:N - The attacker performs open, disconnect, and close on their own fds against an already-attached BCD2000 (DJ workstation/kiosk). No separate victim action such as plugging a device or clicking is required during exploitation.\nS:U - The slab use-after-free of struct urb and the subsequent usb_submit_urb run entirely in the host kernel. This is ordinary local privilege escalation, not a VM, IOMMU, or sandbox boundary escape.\nC:H - KASAN shows a use-after-free read in usb_submit_urb of the dangling midi_out_urb after usb_free_urb. Reclaiming the URB slab lets the attacker supply URB fields that the USB core then reads, enabling kernel disclosure, as with other heap UAFs.\nI:H - bcd2000_midi_send() writes transfer_buffer_length on the freed URB and then submits it. A reclaimed fake URB plus usb_submit_urb is a heap write and control-flow primitive (completion handler/DMA setup) suitable for hijack, so integrity impact is High.\nA:H - The UAF oopses the kernel (KASAN slab-use-after-free in bcd2000_midi_send and usb_submit_urb). The attacker can repeat connect/disconnect to crash on demand, so availability impact is High."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/usb/bcd2000/bcd2000.c"],"versions":[{"version":"b47a22290d581277be70e8a597824a4985d39e83","lessThan":"9af08677aa57debaca5b57c8045c52a83d3dd376","status":"affected","versionType":"git"},{"version":"b47a22290d581277be70e8a597824a4985d39e83","lessThan":"5a77febac6faf6da40fbb4555f703eeb91b58130","status":"affected","versionType":"git"},{"version":"b47a22290d581277be70e8a597824a4985d39e83","lessThan":"3c00004f134fc819f9d9e202c6a64acde0a1f8d0","status":"affected","versionType":"git"},{"version":"b47a22290d581277be70e8a597824a4985d39e83","lessThan":"6c07aad8a7c9ef8ebc4d03a964b882123a349a2e","status":"affected","versionType":"git"},{"version":"b47a22290d581277be70e8a597824a4985d39e83","lessThan":"eb482a06791d6168beb8c78cc904ac5a5ed96a55","status":"affected","versionType":"git"},{"version":"b47a22290d581277be70e8a597824a4985d39e83","lessThan":"7df3194bdb7479cad9199889655a566a2c0c1d1b","status":"affected","versionType":"git"},{"version":"b47a22290d581277be70e8a597824a4985d39e83","lessThan":"b06ebc7fe25a6af4a9f6e4a3d4236a4178ad4b01","status":"affected","versionType":"git"},{"version":"b47a22290d581277be70e8a597824a4985d39e83","lessThan":"459d3a64766f5ca2f1886daeaf24582831a5f5ab","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/usb/bcd2000/bcd2000.c"],"versions":[{"version":"3.16","status":"affected"},{"version":"0","lessThan":"3.16","status":"unaffected","versionType":"semver"},{"version":"5.10.270","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.221","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.188","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.157","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.109","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.50","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.4","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"5.10.270"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"5.15.221"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"6.12.109"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"6.18.50"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"7.3-rc1"}]}]}],"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"}],"title":"ALSA: bcd2000: clear the URB pointers on disconnect","x_generator":{"engine":"bippy-1.2.0"}}}}