CVE-2026-98837ALSA: caiaq: unregister the input device when probe fails

Official description

In the Linux kernel, the following vulnerability has been resolved: ALSA: caiaq: unregister the input device when probe fails setup_card() registers the input device, whose name and phys point into struct snd_usb_caiaqdev, and then goes on to snd_card_register() and snd_usb_caiaq_control_init(). If either fails, snd_probe() calls snd_card_free(), which frees the device state but leaves the input device registered: card_free() only clears the pointer, and the input device is unregistered from snd_disconnect() alone. Reading its "uevent" attribute afterwards dereferences freed memory: BUG: KASAN: slab-use-after-free in string+0x4a9/0x4f0 Read of size 1 at addr ffff8880208f5043 by task caiaq/4967 add_uevent_var+0x183/0x3a0 input_dev_uevent+0x162/0x900 dev_uevent+0x2f1/0x870 uevent_show+0x1ca/0x3a0 ... Unregister the input device on the probe error path, as snd_disconnect() does. snd_usb_caiaq_input_disconnect() is a no-op when no input device was registered. Reproduced with a raw-gadget Audio Kontrol 1 and a temporary hack that makes snd_usb_caiaq_control_init() fail.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/7017c9dda1ebbab428a6fd29c841596b5c9c84d1
• https://git.kernel.org/stable/c/8315ea07ebb2497531ff42dd640396f6f1d4a8f0
• https://git.kernel.org/stable/c/1d5d194594ff616ad36a052bde739d1cf5855b95
• https://git.kernel.org/stable/c/df2787819bd137111b56b8631dd581b0cce7144d
• https://git.kernel.org/stable/c/850810c12686f80cdf7530f4f21e0157d904f739
• https://git.kernel.org/stable/c/84727facd8506140cd04f2b0a8b1c4ddeac41cea
• https://git.kernel.org/stable/c/2e5a413cc2a489c9427ecd3d73ad764bfb0c7103
• https://git.kernel.org/stable/c/0b7bd20f6379bc5e431fd74d866390f5b5b63f3c