Bug 2461538 (CVE-2026-31582)

Summary: CVE-2026-31582 kernel: hwmon: (powerz) Fix use-after-free on USB disconnect
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's hwmon subsystem. A local attacker, by disconnecting a USB device, could trigger a use-after-free vulnerability in the powerz driver. This occurs when the driver attempts to access a Universal Serial Bus Request Block (URB) after it has been freed during the disconnect process. This flaw can lead to system instability or a denial of service (DoS).
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Description OSIDB Bzimport 2026-04-24 15:07:18 UTC 
In the Linux kernel, the following vulnerability has been resolved:

hwmon: (powerz) Fix use-after-free on USB disconnect

After powerz_disconnect() frees the URB and releases the mutex, a
subsequent powerz_read() call can acquire the mutex and call
powerz_read_data(), which dereferences the freed URB pointer.

Fix by:
 - Setting priv->urb to NULL in powerz_disconnect() so that
   powerz_read_data() can detect the disconnected state.
 - Adding a !priv->urb check at the start of powerz_read_data()
   to return -ENODEV on a disconnected device.
 - Moving usb_set_intfdata() before hwmon registration so the
   disconnect handler can always find the priv pointer.
Comment 1 Keith Grant 2026-04-24 18:31:51 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026042412-CVE-2026-31582-cf91@gregkh/T