kernel/linux.git/sound/usb, branch v7.2-rc1

ALSA: FCP: Fix NULL pointer dereference in interface lookup

2026-06-26T05:46:59+00:00

A malformed USB device can provide a vendor-specific interface without any endpoint descriptors. fcp_find_fc_interface() currently selects the first vendor-specific interface and reads endpoint 0 from it, without checking whether the interface actually has any endpoints. When bNumEndpoints is zero, no endpoint array is allocated for the parsed alternate setting, so get_endpoint(..., 0) yields an invalid endpoint descriptor pointer. Dereferencing it through usb_endpoint_num() then triggers a NULL pointer dereference. Skip vendor-specific interfaces that do not have any endpoints. Fixes: 46757a3e7d50 ("ALSA: FCP: Add Focusrite Control Protocol driver") Reported-by: Jiaming Zhang Closes: https://lore.kernel.org/lkml/CANypQFb1EHj0xX8bA1WxSOSK-5xca6ZNKzOQcp12=s=puY7VFw@mail.gmail.com/ Signed-off-by: Jiaming Zhang Link: https://patch.msgid.link/20260625134933.425785-1-r772577952@gmail.com Signed-off-by: Takashi Iwai

ALSA: usb-audio: qcom: Free QMI handle

2026-06-25T11:56:21+00:00

qc_usb_audio_probe() allocates svc->uaudio_svc_hdl separately from the uaudio_qmi_svc object. qmi_handle_release() releases the resources owned by an initialized QMI handle, but does not free the memory containing the struct qmi_handle itself. The probe error path and the remove path currently release the handle and then free svc, losing the last pointer to the separately allocated handle. This leaks one struct qmi_handle on each affected probe unwind and on each successful probe/remove cycle. Free the handle after qmi_handle_release() in both paths. Signed-off-by: Xu Rao Link: https://patch.msgid.link/9108EC860F3F87DF+20260623071308.2549182-1-raoxu@uniontech.com Signed-off-by: Takashi Iwai

ALSA: usb-audio: avoid kobject path lookup in DualSense match

2026-06-25T11:52:32+00:00

The DualSense jack-detection input handler verifies that a matching input device belongs to the same physical controller by building kobject path strings for both the input device and the USB audio device, then comparing the path prefix. This was observed when a weak physical connection caused the controller to rapidly disconnect and reconnect. During that repeated hotplug, snd_dualsense_ih_match() can run while the controller's USB device is being disconnected. kobject_get_path() walks ancestor kobjects and dereferences their names; if the USB device kobject name is no longer valid, this can fault in strlen(): RIP: 0010:strlen+0x10/0x30 Call Trace: kobject_get_path+0x34/0x150 snd_dualsense_ih_match+0x49/0xd0 [snd_usb_audio] input_register_device+0x566/0x6a0 ps_probe+0xb89/0x1590 [hid_playstation] The same ownership check can be done without building kobject path strings. The input device is parented below the HID device, USB interface and USB device, so walking the input device parent chain and comparing against the mixer USB device preserves the check without dereferencing kobject names during disconnect. Fixes: 79d561c4ec04 ("ALSA: usb-audio: Add mixer quirk for Sony DualSense PS5") Cc: Assisted-by: Cute:gpt-5.5 Signed-off-by: Darvell Long Link: https://patch.msgid.link/20260624143723.2986353-1-contact@darvell.me Signed-off-by: Takashi Iwai

ALSA: FCP: Add Focusrite ISA C8X support

2026-06-23T09:46:02+00:00

Add USB PID 0x821e to the list of devices handled by the Focusrite Control Protocol (FCP) driver. Cc: stable@vger.kernel.org Signed-off-by: Geoffrey D. Bennett Link: https://patch.msgid.link/ajlw4HK+2RSW3nUl@m.b4.vu Signed-off-by: Takashi Iwai

ALSA: usb-audio: Kill MIDI 2.0 URBs before freeing endpoints

2026-06-19T08:49:21+00:00

MIDI 2.0 input URBs are started during snd_usb_midi_v2_create(). A later setup failure can still jump to snd_usb_midi_v2_free(), which currently frees each endpoint and its coherent URB buffers without first stopping the submitted URBs. A completion can then dereference the embedded URB context and endpoint state after they have been freed, or try to resubmit from the stale endpoint. This was observed as a KASAN slab-use-after-free in input_urb_complete(). The buggy scenario involves two paths, with each column showing the order within that path: probe error path: USB completion path: 1. start_input_streams() submits 1. The HCD still owns a input URBs. submitted input URB. 2. A later setup helper returns 2. input_urb_complete() runs an error. with urb->context in ep. 3. snd_usb_midi_v2_free() frees 3. The completion reads ep endpoint storage and URB buffers. state and can requeue URBs. Make the endpoint destructor follow the same teardown ordering used for disconnect when the endpoint has not already been disconnected: publish ep->disconnected, kill the URBs synchronously, and drain the endpoint before freeing URB buffers and endpoint storage. The guard avoids repeating the stop sequence after the normal snd_usb_midi_v2_disconnect_all() path, while still synchronizing the direct MIDI 2.0 create-error free path. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in input_urb_complete+0x37/0x1b0 Workqueue: usb_hub_wq hub_event RIP: 0010:_raw_spin_unlock_irq+0x2e/0x50 Read of size 8 Call trace: dump_stack_lvl+0x77/0xb0 print_report+0xce/0x5f0 input_urb_complete+0x37/0x1b0 (sound/usb/midi2.c:186) srso_alias_return_thunk+0x5/0xfbef5 __virt_addr_valid+0x19f/0x330 kasan_report+0xe0/0x110 __usb_hcd_giveback_urb+0x112/0x1d0 dummy_timer+0xaaa/0x19a0 lock_is_held_type+0x9a/0x110 __lock_acquire+0x467/0x28b0 mark_held_locks+0x40/0x70 _raw_spin_unlock_irqrestore+0x44/0x60 lockdep_hardirqs_on_prepare+0xbb/0x1a0 __hrtimer_run_queues+0x101/0x520 hrtimer_run_softirq+0xd0/0x130 handle_softirqs+0x15b/0x670 __irq_exit_rcu+0xd0/0x170 irq_exit_rcu+0xe/0x20 sysvec_apic_timer_interrupt+0x6c/0x80 asm_sysvec_apic_timer_interrupt+0x1a/0x20 Fixes: d9c99876868c ("ALSA: usb-audio: Create UMP blocks from USB MIDI GTBs") Assisted-by: Codex:gpt-5.5 Signed-off-by: Cen Zhang Link: https://patch.msgid.link/20260618170010.191433-1-zzzccc427@gmail.com Signed-off-by: Takashi Iwai

ALSA: usb-audio: Add quirk for YAMAHA CDS3000

2026-06-18T15:48:56+00:00

This quirk is identical to the one for the Yamaha Steinberg UR22, here applied to a CD player that also uses the Steinberg USB interface. This quirk is necessary to avoid sporadic "clic" noise when using the DAC of the player. Signed-off-by: Jean-Louis Colaco Link: https://patch.msgid.link/20260618113202.8363-1-jean-louis.colaco@orange.fr Signed-off-by: Takashi Iwai

ALSA: usb-audio: qcom: clear opened when stream enable fails

2026-06-18T10:44:59+00:00

On enable, subs->opened is set before the service_interval is validated; an invalid interval jumps to the response label without clearing it, so the substream is wedged at -EBUSY until a disable or disconnect. Clear subs->opened on the enable error path. Fixes: 326bbc348298a ("ALSA: usb-audio: qcom: Introduce QC USB SND offloading support") Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Michael Bommarito Link: https://patch.msgid.link/20260618025126.1862954-3-michael.bommarito@gmail.com Signed-off-by: Takashi Iwai

ALSA: usb-audio: qcom: reject stream disable with no active interface

2026-06-18T10:43:02+00:00

handle_uaudio_stream_req() resolves an interface index with info_idx_from_ifnum(), which returns -EINVAL when no interface matches. The enable branch and the response: cleanup label both guard against a negative index, but the disable branch does not: it forms info = &uadev[pcm_card_num].info[info_idx] and dereferences it. uadev[].info is a pointer allocated only when a stream is first enabled, so a negative info_idx on the disable path is unsafe in two ways: - If the card was never enabled, .info is NULL and &info[-EINVAL] is a wild pointer; reading info->data_ep_pipe faults (kernel oops). - If the card was enabled at least once (.info allocated) and the disable names an interface that does not match, &info[-EINVAL] points before the allocation; info->data_ep_pipe / info->sync_ep_pipe are an out-of-bounds slab read and, when non-zero, an out-of-bounds 4-byte write (both pipe fields are cleared to 0). That is memory corruption, not just a NULL dereference. The request is reachable from unprivileged local userspace over AF_QIPCRTR. Reject a disable request with no resolved interface, matching the guard the enable path already has. Fixes: 326bbc348298a ("ALSA: usb-audio: qcom: Introduce QC USB SND offloading support") Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Michael Bommarito Link: https://patch.msgid.link/20260618025126.1862954-2-michael.bommarito@gmail.com Signed-off-by: Takashi Iwai

ALSA: caiaq: bound the length in the EP1 input parsers

2026-06-18T10:37:50+00:00

snd_caiaq_input_read_erp() and snd_caiaq_input_read_io() can be reached from snd_usb_caiaq_input_dispatch(). They read fixed byte offsets from the reply buffer without checking the reported length. On a short reply they decode stale bytes left from a previous, longer report and feed them to the input layer. This is not an out-of-bounds access. Every offset is a compile-time driver constant. The largest is buf[21] in the Maschine ERP case. The EP1 transfer buffer ep1_in_buf is EP1_BUFSIZE (64) bytes, and the USB core caps actual_length at 64, so a short reply only reads in-bounds stale data. Acting on data the device did not send is still wrong, so bail out per usb_id case when the reply is shorter than the bytes that case consumes. read_erp: AK1 needs 2 bytes, Kore needs 16, Maschine needs 22. read_io: the Kore case needs 5 bytes (buf[4]) and the Traktor Kontrol X1 case needs 7 (buf[5]/buf[6]). The preceding key bit loop is already bounded by "i < len * 8" and is left untouched. snd_caiaq_input_read_analog() and snd_usb_caiaq_maschine_dispatch() are not changed. Their callers already floor the reply length. Suggested-by: Takashi Iwai Signed-off-by: Maoyi Xie Link: https://patch.msgid.link/178176259547.3343534.6659489917322808916@maoyixie.com Signed-off-by: Takashi Iwai

ALSA: caiaq: fix out-of-bounds read in the Traktor Kontrol S4 input parser

2026-06-18T10:37:40+00:00

snd_usb_caiaq_tks4_dispatch() decodes the Traktor Kontrol S4 input stream in fixed 16-byte (TKS4_MSGBLOCK_SIZE) message blocks. On every iteration it advances buf and subtracts the block size while looping on "while (len)". len is urb->actual_length. That value is supplied by the device and is not guaranteed to be a multiple of 16. When a final short block leaves len between 1 and 15, the loop runs once more, reads up to buf[15], and then does "len -= TKS4_MSGBLOCK_SIZE". As len is unsigned this underflows to a huge value. The loop then keeps iterating and walking buf far past the end of the 512-byte ep4_in_buf, reading out of bounds until a bogus block id happens to be hit. Iterate only while a full message block is available. This stops the unsigned underflow and silently drops any trailing partial block, which carries no complete control value anyway. The sibling endpoint-4 parsers are not affected. The Traktor Kontrol X1 and Maschine arms in snd_usb_caiaq_ep4_reply_dispatch() floor urb->actual_length before dispatching. Fixes: 15c5ab607045 ("ALSA: snd-usb-caiaq: Add support for Traktor Kontrol S4") Cc: stable@vger.kernel.org Signed-off-by: Maoyi Xie Link: https://patch.msgid.link/178176259547.3343534.2724779296835237429@maoyixie.com Signed-off-by: Takashi Iwai