CVE-2026-46048
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk7th percentile - higher than 7% of all known CVEs
Summary
A vulnerability has been identified in the Linux kernel related to a usb_dev reference leak during ALSA: caiaq device initialization failure. The issue is that the create_card() function does not release the reference, leading to a leak of the usb_device structure and its allocations.
Risk Assessment
The reference leak may lead to inefficient memory management, which could affect system stability and the performance of applications using ALSA in the long run.
Recommendation
It is recommended to update the Linux kernel to the version that includes the fix to eliminate the reference leak issue. Additionally, monitor the system for potential memory-related problems.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: ALSA: caiaq: fix usb_dev refcount leak on probe failure 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().