lwn.git/sound/usb/caiaq, branch master

ALSA: caiaq: Don't abort when no input device is available

2026-04-28T06:13:33+00:00

The previous fix to handle the error from setup_card() caused a regression for the models that have no dedicated input device; snd_usb_caiaq_input_init() just returns -EINVAL, and we treat it as a fatal error although it should be ignored. As a regression fix, change the error code to -ENODEV, and ignore this error in the callee, to continue probing. Fixes: 28abd224db4a ("ALSA: caiaq: Handle probe errors properly") Cc: Link: https://bugzilla.kernel.org/show_bug.cgi?id=221423 Link: https://patch.msgid.link/20260427145642.6637-1-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: caiaq: Fix potentially leftover ep1_in_urb at error path

2026-04-28T06:12:58+00:00

The previous fix for handling the error from setup_card() missed that an internal URB cdev->ep1_in_urb might have been already submitted beforehand. In the normal case, this URB gets killed at the disconnection, but in the error path, we didn't do it, hence there can be a potential leak. Fix it in the error path for setup_card(), too. Fixes: 28abd224db4a ("ALSA: caiaq: Handle probe errors properly") Cc: Link: https://patch.msgid.link/20260427123819.890185-1-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: caiaq: fix usb_dev refcount leak on probe failure

2026-04-27T12:38:50+00:00

create_card() takes a reference on the USB device with usb_get_dev() and stores the matching usb_put_dev() in card_free(), which is installed as the snd_card's ->private_free destructor. However, ->private_free is only assigned near the end of init_card(), after several failure points (usb_set_interface(), EP type checks, usb_submit_urb(), the EP1_CMD_GET_DEVICE_INFO exchange, and its timeout). When any of those fail, init_card() returns an error to snd_probe(), which calls snd_card_free(card). Because ->private_free is still NULL, card_free() never runs, the usb_get_dev() reference is not dropped, and the struct usb_device leaks along with its descriptor allocations and device_private. syzbot reproduces this with a malformed UAC3 device whose only valid altsetting is 0; init_card()'s usb_set_interface(usb_dev, 0, 1) call fails with -EIO and triggers the leak. Move the ->private_free assignment into create_card(), immediately after usb_get_dev(), so that every error path reaching snd_card_free() balances the reference. card_free()'s callees (snd_usb_caiaq_input_free, free_urbs, kfree) already tolerate the partially-initialized state because the chip private area is zero-initialized by snd_card_new(). Fixes: 80bb50e2d459 ("ALSA: caiaq: take a reference on the USB device in create_card()") Reported-by: syzbot+2afd7e71155c7e241560@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=2afd7e71155c7e241560 Tested-by: syzbot+2afd7e71155c7e241560@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Deepanshu Kartikey Link: https://patch.msgid.link/20260426001934.70813-1-kartikey406@gmail.com Signed-off-by: Takashi Iwai

ALSA: caiaq: Fix control_put() result and cache rollback

2026-04-17T15:52:00+00:00

control_put() always returns 1 and updates cdev->control_state[] before sending the USB command. It also ignores transport errors from usb_bulk_msg(), snd_usb_caiaq_send_command(), and snd_usb_caiaq_send_command_bank(). That breaks the ALSA .put() contract and can leave control_get() reporting a cached value the device never accepted. Return 0 for unchanged values, propagate transport failures, and restore the cached byte when the write fails. Fixes: 8e3cd08ed8e59 ("[ALSA] caiaq - add control API and more input features") Cc: stable@vger.kernel.org Signed-off-by: Cássio Gabriel Link: https://patch.msgid.link/20260417-caiaq-control-put-v1-1-c37826e92447@gmail.com Signed-off-by: Takashi Iwai

ALSA: caiaq: Handle probe errors properly

2026-04-15T12:26:19+00:00

The probe procedure of setup_card() in caiaq driver doesn't treat the error cases gracefully, e.g. the error from snd_card_register() calls snd_card_free() but continues. This would lead to a UAF for the further calls like snd_usb_caiaq_control_init(), as Berk suggested in another patch in the link below. However, the problem is not only that; in general, this function drops the all error handlings (as it's a void function) although its caller can propagate an error to snd_probe(), which eventually calls snd_card_free() as a proper error path. That said, we should treat each error case in setup_card(), and just return the error code promptly, which is then handled later as a fatal error in snd_probe(). This patch achieves it by changing the setup_card() to return an error code. Also, the superfluous snd_card_free() call is removed, too. Note that card->private_free can be set still safely at returning an error. All called functions in card_free() have checks of the unassigned resources or NULL checks. Fixes: 8e3cd08ed8e5 ("[ALSA] caiaq - add control API and more input features") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/20260413034941.1131465-2-berkcgoksel@gmail.com Link: https://patch.msgid.link/20260414105916.364073-1-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: caiaq: take a reference on the USB device in create_card()

2026-04-13T05:33:15+00:00

The caiaq driver stores a pointer to the parent USB device in cdev->chip.dev but never takes a reference on it. The card's private_free callback, snd_usb_caiaq_card_free(), can run asynchronously via snd_card_free_when_closed() after the USB device has already been disconnected and freed, so any access to cdev->chip.dev in that path dereferences a freed usb_device. On top of the refcounting issue, the current card_free implementation calls usb_reset_device(cdev->chip.dev). A reset in a free callback is inappropriate: the device is going away, the call takes the device lock in a teardown context, and the reset races with the disconnect path that the callback is already cleaning up after. Take a reference on the USB device in create_card() with usb_get_dev(), drop it with usb_put_dev() in the free callback, and remove the usb_reset_device() call. Fixes: b04dcbb7f7b1 ("ALSA: caiaq: Use snd_card_free_when_closed() at disconnection") Cc: stable@vger.kernel.org Cc: Andrey Konovalov Signed-off-by: Berk Cem Goksel Link: https://patch.msgid.link/20260413034941.1131465-3-berkcgoksel@gmail.com Signed-off-by: Takashi Iwai

ALSA: caiaq: fix stack out-of-bounds read in init_card

2026-03-30T07:31:35+00:00

The loop creates a whitespace-stripped copy of the card shortname where `len < sizeof(card->id)` is used for the bounds check. Since sizeof(card->id) is 16 and the local id buffer is also 16 bytes, writing 16 non-space characters fills the entire buffer, overwriting the terminating nullbyte. When this non-null-terminated string is later passed to snd_card_set_id() -> copy_valid_id_string(), the function scans forward with `while (*nid && ...)` and reads past the end of the stack buffer, reading the contents of the stack. A USB device with a product name containing many non-ASCII, non-space characters (e.g. multibyte UTF-8) will reliably trigger this as follows: BUG: KASAN: stack-out-of-bounds in copy_valid_id_string sound/core/init.c:696 [inline] BUG: KASAN: stack-out-of-bounds in snd_card_set_id_no_lock+0x698/0x74c sound/core/init.c:718 The off-by-one has been present since commit bafeee5b1f8d ("ALSA: snd_usb_caiaq: give better shortname") from June 2009 (v2.6.31-rc1), which first introduced this whitespace-stripping loop. The original code never accounted for the null terminator when bounding the copy. Fix this by changing the loop bound to `sizeof(card->id) - 1`, ensuring at least one byte remains as the null terminator. Fixes: bafeee5b1f8d ("ALSA: snd_usb_caiaq: give better shortname") Cc: stable@vger.kernel.org Cc: Andrey Konovalov Reported-by: Berk Cem Goksel Signed-off-by: Berk Cem Goksel Link: https://patch.msgid.link/20260329133825.581585-1-berkcgoksel@gmail.com Signed-off-by: Takashi Iwai

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

ALSA: caiaq: Use guard() for spin locks

2025-09-01T11:54:06+00:00

Clean up the code using guard() for spin locks. Merely code refactoring, and no behavior change. Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20250829150724.6886-10-tiwai@suse.de