CVEvulnerability

CVE-2026-46048

5.5 MEDIUM Published 2026-05-27 Modified 2026-06-17 Official page ↗
Status
Analyzed
Published
2026-05-27
Last modified
2026-06-17
Assigner
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS 3.1 ([email protected])
5.5 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Description

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().

Affected configurations

• linux linux kernel (>= 6.6.136 < 6.6.140) • linux linux kernel (>= 6.12.84 < 6.12.86) • linux linux kernel (>= 6.18.25 < 6.18.27) • linux linux kernel (>= 7.0.2 < 7.0.4) • linux linux kernel 7.1

References