ghsa-3wr8-h4v3-7726
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
net: usb: asix: hold PM usage ref to avoid PM/MDIO + RTNL deadlock
Prevent USB runtime PM (autosuspend) for AX88772* in bind.
usbnet enables runtime PM (autosuspend) by default, so disabling it via the usb_driver flag is ineffective. On AX88772B, autosuspend shows no measurable power saving with current driver (no link partner, admin up/down). The ~0.453 W -> ~0.248 W drop on v6.1 comes from phylib powering the PHY off on admin-down, not from USB autosuspend.
The real hazard is that with runtime PM enabled, ndo_open() (under RTNL) may synchronously trigger autoresume (usb_autopm_get_interface()) into asix_resume() while the USB PM lock is held. Resume paths then invoke phylink/phylib and MDIO, which also expect RTNL, leading to possible deadlocks or PM lock vs MDIO wake issues.
To avoid this, keep the device runtime-PM active by taking a usage reference in ax88772_bind() and dropping it in unbind(). A non-zero PM usage count blocks runtime suspend regardless of userspace policy (.../power/control - pm_runtime_allow/forbid), making this approach robust against sysfs overrides.
Holding a runtime-PM usage ref does not affect system-wide suspend; system sleep/resume callbacks continue to run as before.
{
"affected": [],
"aliases": [
"CVE-2025-40120"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-11-12T11:15:41Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: usb: asix: hold PM usage ref to avoid PM/MDIO + RTNL deadlock\n\nPrevent USB runtime PM (autosuspend) for AX88772* in bind.\n\nusbnet enables runtime PM (autosuspend) by default, so disabling it via\nthe usb_driver flag is ineffective. On AX88772B, autosuspend shows no\nmeasurable power saving with current driver (no link partner, admin\nup/down). The ~0.453 W -\u003e ~0.248 W drop on v6.1 comes from phylib powering\nthe PHY off on admin-down, not from USB autosuspend.\n\nThe real hazard is that with runtime PM enabled, ndo_open() (under RTNL)\nmay synchronously trigger autoresume (usb_autopm_get_interface()) into\nasix_resume() while the USB PM lock is held. Resume paths then invoke\nphylink/phylib and MDIO, which also expect RTNL, leading to possible\ndeadlocks or PM lock vs MDIO wake issues.\n\nTo avoid this, keep the device runtime-PM active by taking a usage\nreference in ax88772_bind() and dropping it in unbind(). A non-zero PM\nusage count blocks runtime suspend regardless of userspace policy\n(.../power/control - pm_runtime_allow/forbid), making this approach\nrobust against sysfs overrides.\n\nHolding a runtime-PM usage ref does not affect system-wide suspend;\nsystem sleep/resume callbacks continue to run as before.",
"id": "GHSA-3wr8-h4v3-7726",
"modified": "2025-11-12T12:30:26Z",
"published": "2025-11-12T12:30:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-40120"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1534517300e12f2930b6ff477b8820ff658afd11"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3d3c4cd5c62f24bb3cb4511b7a95df707635e00a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3e96cd27ff1a004d84908c1b6cc68ac60913874e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/71a0ba7fdaf8d035426912a4ed7bf1738a81010c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/724a9db84188f80ef60b1f21cc7b4e9c84e0cb64"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9d8bcaf6fae1bd82bc27ec09a2694497e6f6c4b4"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
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