FKIE_CVE-2026-46048
Vulnerability from fkie_nvd - Published: 2026-05-27 14:17 - Updated: 2026-05-27 14:48
Severity
Summary
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().
References
Impacted products
| Vendor | Product | Version |
|---|
{
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: caiaq: fix usb_dev refcount leak on probe failure\n\ncreate_card() takes a reference on the USB device with usb_get_dev()\nand stores the matching usb_put_dev() in card_free(), which is\ninstalled as the snd_card\u0027s -\u003eprivate_free destructor.\n\nHowever, -\u003eprivate_free is only assigned near the end of init_card(),\nafter several failure points (usb_set_interface(), EP type checks,\nusb_submit_urb(), the EP1_CMD_GET_DEVICE_INFO exchange, and its\ntimeout). When any of those fail, init_card() returns an error to\nsnd_probe(), which calls snd_card_free(card). Because -\u003eprivate_free\nis still NULL, card_free() never runs, the usb_get_dev() reference\nis not dropped, and the struct usb_device leaks along with its\ndescriptor allocations and device_private.\n\nsyzbot reproduces this with a malformed UAC3 device whose only valid\naltsetting is 0; init_card()\u0027s usb_set_interface(usb_dev, 0, 1) call\nfails with -EIO and triggers the leak.\n\nMove the -\u003eprivate_free assignment into create_card(), immediately\nafter usb_get_dev(), so that every error path reaching snd_card_free()\nbalances the reference. card_free()\u0027s callees (snd_usb_caiaq_input_free,\nfree_urbs, kfree) already tolerate the partially-initialized state\nbecause the chip private area is zero-initialized by snd_card_new()."
}
],
"id": "CVE-2026-46048",
"lastModified": "2026-05-27T14:48:03.013",
"metrics": {},
"published": "2026-05-27T14:17:24.310",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/21ca595aafa40d3ac70eab1f4cb62cc00ca21657"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/50c6a1f05973f56d23280c9d7645a7a5734e0907"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/6153878c5255bb69b7d0868105ca078ef13cbcf8"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/7a5f1cd22d47f8ca4b760b6334378ae42c1bd24b"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/da3b8fd6a202d94fef11a443abc9171c52426a1c"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
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Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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