kernel/linux.git/sound/usb, branch v7.2-rc7

ALSA: usb-audio: Fix sticky mixer regressions on M-Audio Fast Track Ultra

2026-08-07T08:35:31+00:00

The recent fix for sticky mixer volumes caused regressions of M-audio Fast Track Ultra device, where the mixer state is kept to the default value. Add the quirk entries to tolerate the broken mixer behavior. As the device is known to work in the implicit feedback mode, explicitly enable the implicit feedback mode, too. Since there are two FTU models that are almost identical, both entries are added in this patch (0763:2080 and 0763:2081). Fixes: 86aa1ea1f15c ("ALSA: usb-audio: Do not expose sticky mixers") Link: https://bugzilla.suse.com/show_bug.cgi?id=1273166 Link: https://patch.msgid.link/20260807083418.1712585-1-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: usx2y: bound the hwdep mmap fault offset

2026-08-05T07:37:27+00:00

snd_us428ctls_vm_fault() turns the faulting page offset into a kernel address with no bound of any kind: offset = vmf->pgoff << PAGE_SHIFT; vaddr = (char *)(...)->us428ctls_sharedmem + offset; page = virt_to_page(vaddr); get_page(page); vmf->page = page; return 0; snd_us428ctls_mmap() checks only the length of the mapping, never the offset, and us428ctls_sharedmem is a single page from alloc_pages_exact(). For a character device file_mmap_size_max() returns ULONG_MAX, so the mm layer imposes no ceiling either. Every page offset above zero resolves to a struct page outside the object, and the handler installs it into the caller's address space read-write; the vma is not marked read-only. The caller picks the page frame with a single mmap() argument and gets read-write access to a page of kernel memory it does not own; an offset that lands in an unpopulated vmemmap region oopses instead. A process that can open the hwdep node of an attached US-X2Y reaches this after loading the FPGA image through the same node; no capability check is involved. On 7.2.0-rc5 (arm64), mmap() with a large offset: Unable to handle kernel paging request at virtual address fffffdffc45d5ac8 pc : snd_us428ctls_vm_fault+0x68/0x140 [snd_usb_usx2y] Call trace: snd_us428ctls_vm_fault+0x68/0x140 [snd_usb_usx2y] __do_fault __handle_mm_fault handle_mm_fault el0_da Reject any offset outside the shared region. The pcm hwdep handler in usx2yhwdeppcm.c computes its address the same way and needs the same bound. Discovered by XBOW, triaged by Baul Lee Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Federico Kirschbaum Reported-by: Baul Lee Cc: stable@vger.kernel.org Signed-off-by: Baul Lee Link: https://patch.msgid.link/20260805013445.38283-1-baul.lee@xbow.com Signed-off-by: Takashi Iwai

ALSA: usb-audio: fix OOB write on Type II inbound URBs

2026-08-05T07:35:28+00:00

data_ep_set_params() sizes each URB transfer buffer before it adds the Format Type II transfer delimiter: u->packets = urb_packs; u->buffer_size = maxsize * u->packets; if (fmt->fmt_type == UAC_FORMAT_TYPE_II) u->packets++; /* for transfer delimiter */ u->urb = usb_alloc_urb(u->packets, GFP_KERNEL); buffer_size is computed from the pre-increment packet count and never recomputed, so for a Type II endpoint the buffer is one packet short of the packet count the URB is built with. prepare_inbound_urb() then lays out one iso frame per packet and never consults buffer_size: offs = 0; for (i = 0; i < urb_ctx->packets; i++) { urb->iso_frame_desc[i].offset = offs; urb->iso_frame_desc[i].length = ep->curpacksize; offs += ep->curpacksize; } urb->transfer_buffer_length = offs; urb->number_of_packets = urb_ctx->packets; The last descriptor therefore points one packet past the end of the transfer buffer, where the host controller writes device data on every inbound transfer. prepare_silent_urb() and prepare_playback_urb() bound their fill loops by ctx->buffer_size, so only capture is affected. fmt_type comes from the device's audio streaming descriptors, so any device advertising a Type II capture format hits this once userspace sets hw_params on the stream. KASAN on 7.2.0-rc5 (arm64) with a dummy_hcd/raw-gadget device, one report per inbound transfer: BUG: KASAN: slab-out-of-bounds in dummy_timer Write of size 64 at addr ffff0000186171c0 by task cons02/166 __asan_memcpy dummy_timer hrtimer_run_softirq Allocated by task 166: usb_alloc_coherent snd_usb_endpoint_set_params The buggy address is located 0 bytes to the right of allocated 64-byte region [ffff000018617180, ffff0000186171c0) Compute buffer_size after the delimiter packet has been accounted for, and bound the fill loop by buffer_size, as prepare_silent_urb() already does on the outbound side. This grows every Type II URB allocation by one maxsize packet. Discovered by XBOW, triaged by Baul Lee Fixes: 8fdff6a319e7 ("ALSA: snd-usb: implement new endpoint streaming model") Reported-by: Federico Kirschbaum Reported-by: Baul Lee Cc: stable@vger.kernel.org Signed-off-by: Baul Lee Link: https://patch.msgid.link/20260805013441.38245-1-baul.lee@xbow.com Signed-off-by: Takashi Iwai

ALSA: us144mkii: re-anchor capture URBs on resubmission

2026-08-04T16:06:37+00:00

capture_urb_complete() resubmits each capture URB without anchoring it: usb_get_urb(urb); ret = usb_submit_urb(urb, GFP_ATOMIC); Anchoring is a property of a submission, not of the URB. The giveback path calls usb_unanchor_urb() before urb->complete(), so an URB resubmitted from its own completion handler is off the anchor. The capture URBs are anchored once, at stream start, so from the first completion onward tascam->capture_anchor is empty. tascam_free_urbs(), tascam_disconnect(), tascam_suspend() and the stop-work path all call usb_kill_anchored_urbs(&tascam->capture_anchor) to reap the capture URBs before anything is freed. With the anchor empty those calls return immediately and the URBs stay queued on the host controller. tascam_free_urbs() then returns the capture transfer buffers with usb_free_coherent(), and snd_card_free() releases the snd_card allocation that embeds tascam (card->private_data). The controller completes the queued URBs afterwards, writing device-supplied data into the freed transfer buffer, and capture_urb_complete() dereferences the freed driver object. KASAN on 7.2.0-rc5 (arm64): BUG: KASAN: slab-use-after-free in dummy_timer Write of size 512 at addr ffff000015b62000 __asan_memcpy dummy_timer hrtimer_run_softirq Allocated by task 64: usb_alloc_coherent tascam_alloc_urbs tascam_probe Freed by task 170: usb_free_coherent tascam_free_urbs tascam_disconnect usb_unbind_interface BUG: KASAN: slab-use-after-free in capture_urb_complete Read of size 4 at addr ffff0000170ee878 Freed by task 170: release_card_device snd_card_free tascam_disconnect Restore the usb_anchor_urb() between the reference count bump and the resubmission. That also makes the handler's usb_unanchor_urb() failure arm meaningful again and restores usb_kill_anchored_urbs() as a barrier on the disconnect, suspend and stop-work paths. The anchoring was removed on the premise that the URB is already anchored from the initial submission, which does not hold once the first giveback has run. Discovered by XBOW, triaged by Baul Lee Fixes: 5cff1529a2f9 ("ALSA: us144mkii: capture_urb_complete: redundant usb_anchor_urb corrupts anchor list on each resubmission") Reported-by: Federico Kirschbaum Reported-by: Baul Lee Cc: stable@vger.kernel.org Signed-off-by: Baul Lee Link: https://patch.msgid.link/20260804123625.91769-1-baul.lee@xbow.com Signed-off-by: Takashi Iwai

ALSA: FCP: fix OOB write in fcp_meter_ctl_get()

2026-08-04T16:05:50+00:00

fcp_ioctl_set_meter_map() bounds the user-supplied Level Meter map size by the driver's own limit of 255 if (map.map_size < 1 || map.map_size > 255 || map.meter_slots < 1 || map.meter_slots > 255) return -EINVAL; and passes it to fcp_add_new_ctl() as the control's channel count, where it is stored as elem->channels. Every control read writes into struct snd_ctl_elem_value, whose integer array is declared long value[128], so the limit is 128, not 255. fcp_meter_ctl_get() stores one 64-bit word per channel into that array with no bound of its own: for (i = 0; i < elem->channels; i++) { int idx = private->meter_level_map[i]; int value = idx < 0 ? 0 : le32_to_cpu(resp[idx]); ucontrol->value.integer.value[i] = value; } snd_ctl_elem_read_user() serves that object from memdup_user(_control, sizeof(*control)), 1224 bytes on LP64 out of kmalloc-2048. offsetof(struct snd_ctl_elem_value, value) is 72, so element i is written at byte 72 + 8 * i and element 144 already lands past the allocation. At map_size 255 the last store ends at byte 2112, 888 bytes past the object and 64 bytes into the adjacent slab object. The stored words come from the device and meter_level_map[] selects which word lands in which slot, so extent and contents are both controlled. The core does not catch this. snd_ctl_check_elem_info() is reached only from __snd_ctl_elem_info(), which snd_ctl_elem_read() calls under CONFIG_SND_CTL_DEBUG; without that option snd_ctl_skip_validation() is a compile-time true. __snd_ctl_add_replace() validates kcontrol->count and never inspects elem->channels. Installing an oversized map needs CAP_SYS_RAWIO, but the control outlives the hwdep descriptor that created it, so the out-of-bounds stores are issued by any process able to read controls on /dev/snd/controlC0. KASAN on 7.2.0-rc5 (arm64), triggered by an unprivileged control read: BUG: KASAN: slab-out-of-bounds in fcp_meter_ctl_get Write of size 8 at addr ffff000017af04c8 by task fcp_trigger/185 __asan_store8 fcp_meter_ctl_get snd_ctl_elem_read snd_ctl_ioctl Allocated by task 185: memdup_user snd_ctl_ioctl The buggy address is located 0 bytes to the right of allocated 1224-byte region [ffff000017af0000, ffff000017af04c8) Bound the map size by the ABI limit rather than by 255, and bound the store loop at the sink so it cannot run past the value array whatever elem->channels holds. Discovered by XBOW, triaged by Baul Lee Fixes: 46757a3e7d50 ("ALSA: FCP: Add Focusrite Control Protocol driver") Reported-by: Federico Kirschbaum Reported-by: Baul Lee Cc: stable@vger.kernel.org Signed-off-by: Baul Lee Link: https://patch.msgid.link/20260804123611.91715-1-baul.lee@xbow.com Signed-off-by: Takashi Iwai

ALSA: usb-audio: Add QUIRK_FLAG_MIXER_GET_CUR_BROKEN for Logitech PRO X 2 LIGHTSPEED

2026-08-03T07:37:12+00:00

The UAC mixer of the Logitech PRO X 2 LIGHTSPEED has broken mixer GET_CUR behavior but otherwise works fine. Add a quirk table entry matching VID/PID=0x046d/0x0af7 and apply the MIXER_GET_CUR_BROKEN quirk flag to make the mixer usable again. Quirky device sample (after applying the quirk flag): usb 3-2.1: New USB device found, idVendor=046d, idProduct=0af7, bcdDevice= 1.00 usb 3-2.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 usb 3-2.1: Product: PRO X 2 LIGHTSPEED usb 3-2.1: Manufacturer: Logitech usb 3-2.1: SerialNumber: 0000000000000000 usb 3-2.1: 2:0: broken mixer GET_CUR (-18944/0/256 => -2662) usb 3-2.1: 6:0: broken mixer GET_CUR (-18944/0/256 => 0) Fixes: 86aa1ea1f15c ("ALSA: usb-audio: Do not expose sticky mixers") Suggested-by: Brian van den Berg Reported-by: Brian van den Berg Link: https://lore.kernel.org/all/370007e6-b73b-4bfc-8410-a860781c7ad7@proton.me/ Signed-off-by: Rong Zhang Link: https://patch.msgid.link/20260731-uac-lg-pro-x-2-ls-v1-1-268eaefe66ab@rong.moe Signed-off-by: Takashi Iwai

ALSA: usb-audio: Add GET_SAMPLE_RATE quirk for C-Media CM6206

2026-07-29T06:31:42+00:00

The C-Media CM6206 (0d8c:0102) truncates the three-byte sample rate it returns for UAC_GET_CUR to its two low bytes. After the rate has been set to 96000 (0x017700) the device reports back 30464 (0x007700). At probe time the driver initializes every altsetting to its maximum rate, so altsetting 5 is set to 96000 and the warning appears on each plug-in, before anything has opened the device: usb 3-1.3: 1:5 Set sample rate 96000, clock 0 usb 3-1.3: current rate 30464 is different from the runtime rate 96000 That altsetting is the one parse_audio_format_rates_v1() already fixes up for this chip, so this affects every CM6206. Only the read-back is broken, the rate itself is applied: a 1 kHz sine rendered at 96 kHz is recovered at 1000.2 Hz, and a silent fallback to 48000 would have been reported as 0x00bb80 rather than as the low half of the requested rate. Add a QUIRK_FLAG_GET_SAMPLE_RATE entry for the device so the read-back is skipped. Setting the same flag through the quirk_flags module parameter makes the warning disappear while the 96000 init still happens. Signed-off-by: Mikhail Gavrilov Link: https://patch.msgid.link/20260728222239.62749-1-mikhail.v.gavrilov@gmail.com Signed-off-by: Takashi Iwai

ALSA: usb-audio: Clamp frame size in implicit-feedback mode

2026-07-29T06:25:27+00:00

snd_usb_handle_sync_urb() scales received sync packet sizes by the sender's stride and stores the result directly in out_packet->packet_size[i]. If a connected USB device sends an oversized sync packet, this frame count can exceed ep->maxframesize. The un-clamped frame count then propagates to the playback endpoint queue, potentially driving packet transfers beyond the endpoint's hardware frame limits. Cap the calculated frame count against ep->maxframesize in snd_usb_handle_sync_urb() to prevent oversized packets from entering the playback queue. Fixes: 28acb12014fb ("ALSA: usb-audio: use sender stride for implicit feedback") Cc: stable@vger.kernel.org Assisted-by: Jetski:Gemini-3.6-Flash Signed-off-by: Sonali Pradhan Link: https://patch.msgid.link/20260728202432.2354994-1-sonalipradhan@google.com Signed-off-by: Takashi Iwai

ALSA: usb-audio: Fix DMA buffer out-of-bounds write when fill_max is set

2026-07-29T06:23:32+00:00

When a USB audio endpoint requests full packet transfers via the fill_max descriptor flag, data_ep_set_params() promotes ep->curpacksize to ep->maxpacksize. However, maxsize is left at the original sample-rate derived value. Since u->buffer_size is allocated as maxsize * packets, the resulting DMA buffer is far too small for the requested transfer length. When the USB host controller streams up to curpacksize bytes per packet, it writes past the end of the buffer via DMA, corrupting kernel heap memory. Update maxsize to curpacksize when fill_max is set so that the allocated DMA buffer size matches the actual transfer request size. [ changed to reassign maxsize only when ep->fill_max is set -- tiwai ] Fixes: 8fdff6a319e7 ("ALSA: snd-usb: implement new endpoint streaming model") Cc: stable@vger.kernel.org Assisted-by: Jetski:Gemini-3.6-Flash Signed-off-by: Sonali Pradhan Link: https://patch.msgid.link/20260728201716.2347726-1-sonalipradhan@google.com Signed-off-by: Takashi Iwai

ALSA: usb-audio: Add quirk for Corsair Virtuoso (later revision)

2026-07-28T16:30:43+00:00

Add USB mixer mapping quirk for later revisions of the Corsair Virtuoso headset with USB IDs 0x1b1c:0x0a43 (wired) and 0x1b1c:0x0a44 (wireless). These devices exhibit the same mixer label collision as earlier Virtuoso variants: all controls are labelled "Headset", causing applications like PulseAudio to move the sidetone control instead of the main playback volume. Signed-off-by: Robert Abrahamse Link: https://patch.msgid.link/20260728140314.11601-1-denobyte2@gmail.com Signed-off-by: Takashi Iwai