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CVE-2026-80971— ALSA: bcd2000: clear the URB pointers on disconnect

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Linux kernel是美国Linux基金会开源的一个操作系统内核。 Linux kernel存在安全漏洞，该漏洞源于ALSA bcd2000驱动在断开连接时释放URB后未清除指针，对已释放URB的后续提交可导致释放后重用。

CVSS 7.8 · High EPSS 0.16% · P5

Possible ATT&CK Techniques 1 AI

T1059.004 · Unix Shell

Affected Version Matrix 18

VendorProduct Version RangeStatus
Linux Linux b47a22290d581277be70e8a597824a4985d39e83< 9af08677aa57debaca5b57c8045c52a83d3dd376 affected
b47a22290d581277be70e8a597824a4985d39e83< 5a77febac6faf6da40fbb4555f703eeb91b58130 affected
b47a22290d581277be70e8a597824a4985d39e83< 3c00004f134fc819f9d9e202c6a64acde0a1f8d0 affected
b47a22290d581277be70e8a597824a4985d39e83< 6c07aad8a7c9ef8ebc4d03a964b882123a349a2e affected
b47a22290d581277be70e8a597824a4985d39e83< eb482a06791d6168beb8c78cc904ac5a5ed96a55 affected
b47a22290d581277be70e8a597824a4985d39e83< 7df3194bdb7479cad9199889655a566a2c0c1d1b affected
b47a22290d581277be70e8a597824a4985d39e83< b06ebc7fe25a6af4a9f6e4a3d4236a4178ad4b01 affected
b47a22290d581277be70e8a597824a4985d39e83< 459d3a64766f5ca2f1886daeaf24582831a5f5ab affected
… +10 more rows
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I. Basic Information for CVE-2026-80971

Vulnerability Information
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Vulnerability Title
ALSA: bcd2000: clear the URB pointers on disconnect
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: ALSA: bcd2000: clear the URB pointers on disconnect bcd2000_free_usb_related_resources() frees both URBs and leaves the pointers behind: usb_kill_urb(bcd2k->midi_out_urb); usb_kill_urb(bcd2k->midi_in_urb); usb_free_urb(bcd2k->midi_out_urb); usb_free_urb(bcd2k->midi_in_urb); The rawmidi device outlives that call. A substream that is still open when the device is unplugged reaches bcd2000_midi_send() from the trigger path on close. That function writes to the freed URB and then hands it to the USB core: bcd2k->midi_out_urb->transfer_buffer_length = BUFSIZE; ... ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_ATOMIC); usb_kill_urb() does not stop a later submission either, so a submit that races the disconnect can requeue the URB after it has been reaped. midi_in_urb is exposed the same way: bcd2000_input_complete() resubmits it from the completion handler. KASAN on 7.2.0-rc5 (arm64): BUG: KASAN: slab-use-after-free in bcd2000_midi_send [snd_bcd2000] Write of size 4 at addr ffff00001827d388 by task bpoc/168 __asan_store4 bcd2000_midi_send [snd_bcd2000] bcd2000_midi_output_trigger [snd_bcd2000] snd_rawmidi_kernel_write1 close_substream.part.0 Freed by task 168: usb_free_urb bcd2000_disconnect [snd_bcd2000] BUG: KASAN: slab-use-after-free in usb_submit_urb Read of size 8 at addr ffff00001827d3b8 by task bpoc/168 Clear both pointers after freeing and test them on the paths that can still run. Poison the URBs before freeing them: usb_poison_urb() waits for a running completion handler and rejects any later submission, so after it returns the input path is quiesced and only the rawmidi trigger path can still reach bcd2000_midi_send(). No unpoison is needed; the URBs are freed on the next line. Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会开源的一个操作系统内核。 Linux kernel存在安全漏洞，该漏洞源于ALSA bcd2000驱动在断开连接时释放URB后未清除指针，对已释放URB的后续提交可导致释放后重用。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux b47a22290d581277be70e8a597824a4985d39e83 ~ 9af08677aa57debaca5b57c8045c52a83d3dd376 -
Linux Linux 3.16 -

II. Public POCs for CVE-2026-80971

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III. Intelligence Information for CVE-2026-80971

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Patches & Fixes for CVE-2026-80971 (6)

Other References for CVE-2026-80971 (1)

Same Patch Batch · Linux · 2026-09-11 · 431 CVEs total

CVE-2026-89688 9.8 CRITICAL nfsd: drop the stateid, not the stateowner, on seqid_op replay retry
CVE-2026-89656 9.8 CRITICAL libceph: reject buckets with mismatched CRUSH ids
CVE-2026-89655 9.8 CRITICAL ceph: fix UAF in __kick_flushing_caps() on cf entry freed during unlock
CVE-2026-89658 9.8 CRITICAL NFSD: Prevent client use-after-free during NFSv4.0 revoked-state cleanup
CVE-2026-89660 9.8 CRITICAL NFSD: Prevent client use-after-free during admin state revocation
CVE-2026-89659 9.8 CRITICAL NFSD: Prevent client use-after-free during delegation revoke
CVE-2026-89662 9.8 CRITICAL NFSD: Prevent lock owner use-after-free during client teardown
CVE-2026-89669 9.8 CRITICAL nfsd: initialize copy-notify stateid before publishing it
CVE-2026-89674 9.8 CRITICAL nfsd: fix XDR length calculation in nfsd4_ff_encode_layoutget
CVE-2026-89675 9.8 CRITICAL nfsd: fix UAF in async copy cancel and shutdown
CVE-2026-89676 9.8 CRITICAL nfsd: fix stale s2s_cp_stateids IDR entry for async COPY
CVE-2026-89677 9.8 CRITICAL nfsd: fix possible fh_compose of wrong dentry in nfsd4_create_file()
CVE-2026-89681 9.8 CRITICAL nfsd: fix layout fence worker double-reference race
CVE-2026-89686 9.8 CRITICAL nfsd: fix BUG_ON in nfsd4_alloc_layout_stateid on racing delegation revoke
CVE-2026-89478 9.8 CRITICAL sctp: drop a chunk if its transport was removed
CVE-2026-89479 9.8 CRITICAL sctp: stop processing a packet once its association is deleted
CVE-2026-89702 9.8 CRITICAL nfsd: size fh_verify server sockaddr slot by xpt_locallen
CVE-2026-89703 9.8 CRITICAL nfsd: set SC_STATUS_FREED in nfsd4_drop_revoked_stid for delegations
CVE-2026-89482 9.8 CRITICAL nvme-tcp: do not accept C2HData based on blk_rq_payload_bytes() alone
CVE-2026-89708 9.8 CRITICAL nfsd: RCU-protect cl_cb_session to fix use-after-free on session teardown

Showing top 20 of 431 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

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