{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-44954","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-08-21T05:34:56.666Z","datePublished":"2024-09-04T18:35:53.730Z","dateUpdated":"2026-08-05T11:37:18.083Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T11:37:18.083Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: line6: Fix racy access to midibuf\n\nThere can be concurrent accesses to line6 midibuf from both the URB\ncompletion callback and the rawmidi API access.  This could be a cause\nof KMSAN warning triggered by syzkaller below (so put as reported-by\nhere).\n\nThis patch protects the midibuf call of the former code path with a\nspinlock for avoiding the possible races."}],"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 unsynchronized accesses are in `line6_data_received()` (URB completion for the control/MIDI-in endpoint) racing the rawmidi API path, and the driver is only bound when a Line 6 device is already attached — so a local unprivileged user on such a host drives both halves via `/dev/snd/midiC*D*` (and the hwdep node), writing MIDI/sysex to solicit device replies that generate URB completions while concurrently hammering rawmidi read/trigger. No physical access by the attacker is needed in that deployment (audio workstation, live-performance rig).\nAC:L - The attacker controls both sides of the race — one thread issues rawmidi/hwdep writes that make the device respond on the interrupt-in endpoint, another thread concurrently exercises the rawmidi API — and the window can be retried indefinitely at MIDI packet rate. Per the guidance, a race whose both sides the attacker creates is Low.\nPR:L - Only ordinary access to the ALSA rawmidi/hwdep character devices is required, which the console/desktop user gets by default through udev ACLs or `audio` group membership. No CAP_SYS_ADMIN or root is needed.\nUI:N - The attacker performs every step itself — opening the rawmidi node, soliciting device traffic, and racing the accesses. Presence of the Line 6 device is a property of the affected system (the driver does not load otherwise), not a victim action during the attack.\nS:U - The corrupted ring-buffer state, the heap over-read, and the disclosed data all live in the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - syzbot confirmed \"KMSAN: uninit-value in line6_midibuf_read\" at `midibuf.c:185` — racy `pos_read`/`pos_write`/`full` make the reader consume bytes never written, so stale contents of the `kmalloc()`ed 1024-byte `midi_buffer.buf` slab object are memcpy'd into `line6->buffer_message` and delivered to userspace through `snd_rawmidi_receive()`. A stale `length1 = size - pos_write`/`pos_read` pair also lets the copy index past the end of that allocation, and the leak is repeatable, allowing kernel heap contents (pointers, recycled data) to be harvested.\nI:H - `line6_midibuf_write()` computes `length1 = this->size - this->pos_write` and then does `memcpy(this->buf + this->pos_write, data, length1)` re-reading `pos_write`; with no lock, a concurrent index update makes that copy run past the end of the kmalloc-1024 object with device-supplied MIDI bytes, giving an attacker-influenced heap out-of-bounds write, and corrupted indices also feed bogus data into the rawmidi stream.\nA:H - Out-of-bounds reads and writes on the kmalloc-1024 slab object corrupt adjacent allocations and trip sanitizer/hardening checks, producing oops or panic. The bug is a memory-safety error, which per the guidance is High availability impact."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/usb/line6/driver.c"],"versions":[{"version":"705ececd1c60d0f5d6ef2a719008847883516970","lessThan":"643293b68fbb6c03f5e907736498da17d43f0d81","status":"affected","versionType":"git"},{"version":"705ececd1c60d0f5d6ef2a719008847883516970","lessThan":"40f3d5cb0e0cbf7fa697913a27d5d361373bdcf5","status":"affected","versionType":"git"},{"version":"705ececd1c60d0f5d6ef2a719008847883516970","lessThan":"e7e7d2b180d8f297cea6db43ea72402fd33e1a29","status":"affected","versionType":"git"},{"version":"705ececd1c60d0f5d6ef2a719008847883516970","lessThan":"a54da4b787dcac60b598da69c9c0072812b8282d","status":"affected","versionType":"git"},{"version":"705ececd1c60d0f5d6ef2a719008847883516970","lessThan":"c80f454a805443c274394b1db0d1ebf477abd94e","status":"affected","versionType":"git"},{"version":"705ececd1c60d0f5d6ef2a719008847883516970","lessThan":"535df7f896a568a8a1564114eaea49d002cb1747","status":"affected","versionType":"git"},{"version":"705ececd1c60d0f5d6ef2a719008847883516970","lessThan":"51d87f11dd199bbc6a85982b088ff27bde53b48a","status":"affected","versionType":"git"},{"version":"705ececd1c60d0f5d6ef2a719008847883516970","lessThan":"15b7a03205b31bc5623378c190d22b7ff60026f1","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/line6/driver.c"],"versions":[{"version":"2.6.30","status":"affected"},{"version":"0","lessThan":"2.6.30","status":"unaffected","versionType":"semver"},{"version":"4.19.320","lessThanOrEqual":"4.19.*","status":"unaffected","versionType":"semver"},{"version":"5.4.282","lessThanOrEqual":"5.4.*","status":"unaffected","versionType":"semver"},{"version":"5.10.224","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.165","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.105","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.46","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.10.5","lessThanOrEqual":"6.10.*","status":"unaffected","versionType":"semver"},{"version":"6.11","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":"2.6.30","versionEndExcluding":"4.19.320"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"5.4.282"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"5.10.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"5.15.165"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"6.1.105"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"6.6.46"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"6.10.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.30","versionEndExcluding":"6.11"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/643293b68fbb6c03f5e907736498da17d43f0d81"},{"url":"https://git.kernel.org/stable/c/40f3d5cb0e0cbf7fa697913a27d5d361373bdcf5"},{"url":"https://git.kernel.org/stable/c/e7e7d2b180d8f297cea6db43ea72402fd33e1a29"},{"url":"https://git.kernel.org/stable/c/a54da4b787dcac60b598da69c9c0072812b8282d"},{"url":"https://git.kernel.org/stable/c/c80f454a805443c274394b1db0d1ebf477abd94e"},{"url":"https://git.kernel.org/stable/c/535df7f896a568a8a1564114eaea49d002cb1747"},{"url":"https://git.kernel.org/stable/c/51d87f11dd199bbc6a85982b088ff27bde53b48a"},{"url":"https://git.kernel.org/stable/c/15b7a03205b31bc5623378c190d22b7ff60026f1"}],"title":"ALSA: line6: Fix racy access to midibuf","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2024-44954","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-09-10T17:40:10.329711Z"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2024-09-12T17:33:34.296Z"}},{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"},{"url":"https://lists.debian.org/debian-lts-announce/2024/10/msg00003.html"}],"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2025-11-03T22:14:04.124Z"}}]}}