kernel/sound/usb/card.c, branch 0x221E-v0.0.1-v6.19

ALSA: usb-audio: Fix NULL pointer deference in try_to_register_card

2025-10-15T08:17:09Z

In try_to_register_card(), the return value of usb_ifnum_to_if() is passed directly to usb_interface_claimed() without a NULL check, which will lead to a NULL pointer dereference when creating an invalid USB audio device. Fix this by adding a check to ensure the interface pointer is valid before passing it to usb_interface_claimed(). Fixes: 39efc9c8a973 ("ALSA: usb-audio: Fix last interface check for registration") Closes: https://lore.kernel.org/all/CANypQFYtQxHL5ghREs-BujZG413RPJGnO5TH=xjFBKpPts33tA@mail.gmail.com/ Signed-off-by: Jiaming Zhang Signed-off-by: Takashi Iwai

ALSA: usb-audio: make param quirk_flags change-able in runtime

2025-09-28T06:35:29Z

Change its permision from 0644 to 0444, and add runtime processing. Developers now can change it during sysfs, without rebooting, for debugging new buggy devices. Co-developed-by: Takashi Iwai Signed-off-by: Cryolitia PukNgae Signed-off-by: Takashi Iwai

ALSA: usb-audio: improve module param quirk_flags

2025-09-28T06:35:29Z

It accepts strings like `VID:PID:quirk_flag_name1|quirk_flag_name2;...` from now on, so that we can use it to debug USB audio devices more intuitive and flexible. The compatibility of previous form is kept. Co-developed-by: Takashi Iwai Signed-off-by: Cryolitia PukNgae Signed-off-by: Takashi Iwai

ALSA: usb-audio: Replace manual mutex/spinlock with guard()

2025-08-12T06:36:17Z

This is another code cleanup by replacing the manual mutex or spinlock with guard() macros. usb_audio_disconnect() is slightly refactored (split to another function) to apply guard() cleanly, but the rest are rather straightforward conversions. No functional changes but only code refactoring. Link: https://patch.msgid.link/20250811082019.31052-1-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: usb-audio: Copy string more safely

2025-07-11T07:53:36Z

Replace strcpy() and sprintf() usages in the USB audio drivers with the safer versions (strscpy() and scnprintf()) with the proper max size evaluation. Only for safety, no actual behavior change. Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20250710100727.22653-103-tiwai@suse.de

ALSA: usb-audio: Use safer strscpy() instead of strcpy()

2025-07-11T07:53:35Z

Use a safer function strscpy() instead of strcpy() for copying to arrays. Only idiomatic code replacement, and no functional changes. Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20250710100727.22653-100-tiwai@suse.de

ALSA: usb-audio: Allow for rediscovery of connected USB SND devices

2025-04-11T11:02:31Z

In case of notifying SND platform drivers of connection events, some of these use cases, such as offloading, require an ASoC USB backend device to be initialized before the events can be handled. If the USB backend device has not yet been probed, this leads to missing initial USB audio device connection events. Expose an API that traverses the usb_chip array for connected devices, and to call the respective connection callback registered to the SND platform driver. Signed-off-by: Wesley Cheng Acked-by: Mark Brown Link: https://lore.kernel.org/r/20250409194804.3773260-14-quic_wcheng@quicinc.com Signed-off-by: Greg Kroah-Hartman

ALSA: usb-audio: Introduce USB SND platform op callbacks

2025-04-11T11:02:30Z

Allow for different platforms to be notified on USB SND connect/disconnect sequences. This allows for platform USB SND modules to properly initialize and populate internal structures with references to the USB SND chip device. Tested-by: Puma Hsu Tested-by: Daehwan Jung Signed-off-by: Wesley Cheng Acked-by: Mark Brown Link: https://lore.kernel.org/r/20250409194804.3773260-13-quic_wcheng@quicinc.com Signed-off-by: Greg Kroah-Hartman

ALSA: usb-audio: Check for support for requested audio format

2025-04-11T11:02:30Z

Allow for checks on a specific USB audio device to see if a requested PCM format is supported. This is needed for support when playback is initiated by the ASoC USB backend path. Reviewed-by: Pierre-Louis Bossart Signed-off-by: Wesley Cheng Acked-by: Mark Brown Link: https://lore.kernel.org/r/20250409194804.3773260-10-quic_wcheng@quicinc.com Signed-off-by: Greg Kroah-Hartman

ALSA: usb-audio: Export USB SND APIs for modules

2025-04-11T11:02:30Z

Some vendor modules will utilize useful parsing and endpoint management APIs to start audio playback/capture. Reviewed-by: Pierre-Louis Bossart Tested-by: Puma Hsu Tested-by: Daehwan Jung Signed-off-by: Wesley Cheng Acked-by: Mark Brown Link: https://lore.kernel.org/r/20250409194804.3773260-9-quic_wcheng@quicinc.com Signed-off-by: Greg Kroah-Hartman