kernel/linux.git/sound, branch v6.18.45

ALSA: us144mkii: re-anchor capture URBs on resubmission

2026-08-19T16:18:17+00:00

commit 2615f0fb90df8cf5a96133ca4be74294ed288604 upstream. 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 Signed-off-by: Greg Kroah-Hartman

ALSA: hda/tas2781: fix ACPI reference handling

2026-08-19T16:18:17+00:00

commit 8bec01c80e798eca1ae7863cf29bc6befd759db7 upstream. tas2781_read_acpi() gets a reference to the matching ACPI device and then looks up its first physical device node. After taking a reference to the physical device, it immediately drops the ACPI device reference. However, every later failure jumps to an error path that drops the ACPI device reference a second time. This unbalances the reference count and may prematurely release the ACPI device. In addition, acpi_get_first_physical_node() may return NULL. Without a check, the driver passes the NULL physical device to the property helper calls and may dereference it. Return -ENODEV when no physical device is associated with the ACPI node, and remove the duplicate acpi_dev_put() from the common error path. Fixes: bb5f86ea50ff ("ALSA: hda/tas2781: Add tas2781 hda SPI driver") Cc: stable@vger.kernel.org Signed-off-by: Xu Rao Link: https://patch.msgid.link/97EA8F29DA0D9AF7+20260731033554.949564-1-raoxu@uniontech.com Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman

ALSA: FCP: fix OOB write in fcp_meter_ctl_get()

2026-08-19T16:18:17+00:00

commit 620f1e52a46f604635efd0fb78138afd6a513b5d upstream. 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 Signed-off-by: Greg Kroah-Hartman

ALSA: usx2y: bound the hwdep mmap fault offset

2026-08-19T16:18:17+00:00

commit 2ca1eea3cd17930daffe9e429a7c89232036ec24 upstream. 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 Signed-off-by: Greg Kroah-Hartman

ALSA: usb: Fix UAF at delayed release of MIDI2 EPs

2026-08-19T16:18:17+00:00

commit f8a80cfb68613fb7e6452b66447dbc63f435d140 upstream. The recent fix for UAF in ump_to_endpoint() caused another UAF because it tries to dereference the UMP endpoint object, but this might be executed at a delayed context where the endpoint has been already released. Add private_free to clear the associated data for avoiding the further dereference for delayed releases. Fixes: 4a05b2d1b464 ("ALSA: usb-audio: fix use-after-free in ump_to_endpoint()") Reported-by: syzbot+565b1138cfbe549d4422@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=565b1138cfbe549d4422 Cc: Link: https://patch.msgid.link/20260808152009.1947835-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman

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

2026-08-19T16:17:49+00:00

commit 69ee44e1a23be62318189dc4b37fa4ad94053269 upstream. 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 Signed-off-by: Greg Kroah-Hartman

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

2026-08-09T18:25:15+00:00

commit 8d7a30c50c2e58a6839634ed0acde14466d1dc61 upstream. 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 Signed-off-by: Greg Kroah-Hartman

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

2026-08-09T18:25:14+00:00

commit d0199ae1666ff9ae2d1d568d64c3430d4c47f0e5 upstream. 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 Signed-off-by: Greg Kroah-Hartman

ALSA: usb-audio: fix OOB write in snd_usbmidi_akai_output()

2026-08-09T18:25:14+00:00

commit 0970274613fb463d376211450cab066d34ebfe6a upstream. snd_usbmidi_akai_output() computes its fill-loop bound buf_end = ep->max_transfer - MAX_AKAI_SYSEX_LEN - 1; as a signed int, so a small device-advertised bulk-OUT max_transfer makes buf_end negative. The loop guard then compares the u32 urb->transfer_buffer_length against that negative int: the usual arithmetic conversion turns buf_end into a large unsigned value, so the guard stays true and each iteration keeps appending SysEx framing and payload bytes past the end of the URB transfer buffer, which is only max_transfer bytes long. A USB device that advertises a tiny bulk-OUT endpoint can therefore trigger an attacker-length- and content-controlled heap out-of-bounds write when a process writes to the created /dev/snd/midiC*D* node. Return early when there is no room for even one SysEx, so the loop is never entered with a bound that would wrap. The loop is the last statement of the function, so bailing out is equivalent to it not running. Discovered by XBOW, triaged by Baul Lee Fixes: 4434ade8c933 ("ALSA: usb-audio: add support for Akai MPD16") Suggested-by: Takashi Iwai Reported-by: Federico Kirschbaum Reported-by: Baul Lee Cc: stable@vger.kernel.org Signed-off-by: Baul Lee Link: https://patch.msgid.link/20260726074500.50145-1-baul.lee@xbow.com Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman

ALSA: usb-audio: fix stack info leak in RME Digiface status

2026-08-09T18:25:14+00:00

commit 441aaad150c57edaf57ee482a79a3bf4c5b7e353 upstream. snd_rme_digiface_read_status() reads a four-word status block from the device into an uninitialised on-stack __le32 buf[4] and, whenever the vendor control-IN transfer does not return a negative error, copies all four words into the caller's status[]. snd_usb_ctl_msg() copies the full requested size back into the caller's buffer regardless of how many bytes the data stage actually delivered: buf = kmemdup(data, size, GFP_KERNEL); err = usb_control_msg(dev, pipe, request, requesttype, value, index, buf, size, timeout); memcpy(data, buf, size); usb_control_msg() returns the transferred length on a short control-IN, which is a non-negative value, and writes only that many bytes. The remainder of the copy back is the kmemdup()ed image of the caller's buffer, so a device answering with a short data stage leaves the trailing words of buf[] holding leftover kernel stack. The only guard in the caller is err < 0, so those words are stored into status[]. They then reach user space: snd_rme_digiface_get_status_val() selects a 16-bit halfword of status[] per the control's reg/mask, and the eight Digiface status controls together expose the whole 16-byte frame to an unprivileged reader of /dev/snd/controlC*. Zero-initialise the buffer so a short read yields zeros instead of stack residue. This mirrors snd_rme_get_status1(), which already clears its output word before the same kind of vendor read. Discovered by XBOW, triaged by Baul Lee Fixes: 611a96f6acf2 ("ALSA: usb-audio: Add mixer quirk for RME Digiface USB") Reported-by: Federico Kirschbaum Reported-by: Baul Lee Cc: stable@vger.kernel.org Signed-off-by: Baul Lee Link: https://patch.msgid.link/20260726065020.46070-1-baul.lee@xbow.com Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman