usb: gadget: u_audio: Fix use-after-free on sound card disconnect
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: u_audio: Fix use-after-free on sound card disconnect g_audio_cleanup() invokes snd_card_free_when_closed() to initiate sound card teardown and immediately frees the underlying struct snd_uac_chip context. However, snd_card_free_when_closed() returns asynchronously while ALSA control elements (kctls) remain open in userspace. When userspace control applications access or close these open file descriptors, kctl callbacks attempt to dereference kctl->private_data pointing to &uac->c_prm or &uac->p_prm within the freed uac structure, resulting in a use-after-free (UAF) memory corruption. Fix this issue by deferring the destruction of struct snd_uac_chip until all references to the ALSA sound card are released. Register a custom card->private_free callback (u_audio_card_free) during g_audio_setup() that frees uac and its associated playback/capture request and ring buffers only when the sound card reference count drops to zero.
CVE-2026-89736
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-89736
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "33f341c1fc60e172a3515c51bdabee11e83d1ee9",
"lessThan": "a7ecd1a04f4f485d7be6443d0f0b2c61a800cb82",
"versionType": "git"
},
{
"status": "affected",
"version": "b131989797f7287d7fdadb2bababc05a15d44750",
"lessThan": "f983793f03148b097977f200298db215cd2d4438",
"versionType": "git"
},
{
"status": "affected",
"version": "3bc7324e4911351e39c54a62e6ca46321cb10faf",
"lessThan": "6f46762196f04464e1050a9ee94e72b917db9010",
"versionType": "git"
},
{
"status": "affected",
"version": "6c67ed9ad9b83e453e808f9b31a931a20a25629b",
"lessThan": "891a8d11f4d5eb50b2ce7570f4f98204a7a57493",
"versionType": "git"
},
{
"status": "affected",
"version": "6c67ed9ad9b83e453e808f9b31a931a20a25629b",
"lessThan": "c74ff0b1a0fca53d3ac185873c87d6a719b30a47",
"versionType": "git"
},
{
"status": "affected",
"version": "6c67ed9ad9b83e453e808f9b31a931a20a25629b",
"lessThan": "4e747c864a88537e18b1ffc19a1954c9686bb8e1",
"versionType": "git"
},
{
"status": "affected",
"version": "6c67ed9ad9b83e453e808f9b31a931a20a25629b",
"lessThan": "79a92896e2bb9471550c56fc23d8d93592f04c27",
"versionType": "git"
},
{
"status": "affected",
"version": "6c67ed9ad9b83e453e808f9b31a931a20a25629b",
"lessThan": "858965947081d10d41d9a1010a540d3d5eea958b",
"versionType": "git"
},
{
"status": "affected",
"version": "3e016ef2e72da93a2ea7afbb45de1b481b44d761",
"versionType": "git"
},
{
"status": "affected",
"version": "3256e152b645fc1e788ba44c2d8ced690113e3e6",
"versionType": "git"
},
{
"status": "affected",
"version": "0eda2004f38d95ef5715d62be884cd344260535b",
"versionType": "git"
},
{
"status": "affected",
"version": "43ca70753dfffd517d2af126da28690f8f615605",
"versionType": "git"
},
{
"status": "affected",
"version": "5.10.177",
"lessThan": "5.10.270",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.15.105",
"lessThan": "5.15.221",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.1.22",
"lessThan": "6.1.188",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.14.312",
"lessThan": "4.15",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.19.280",
"lessThan": "4.20",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.4.240",
"lessThan": "5.5",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.2.9",
"lessThan": "6.3",
"versionType": "semver"
}
],
"programFiles": [
"drivers/usb/gadget/function/u_audio.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.3"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.3",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.270",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.221",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.109",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/usb/gadget/function/u_audio.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89736
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #35213 · Revision 1
- Added to Heist Feed
- Publisher date