CVEvulnerability
CVE-2026-72483
7.8 HIGH
Official page ↗
- Status
- Received
- Published
- 2026-08-15
- Last modified
- 2026-08-17
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
- 7.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Description
In the Linux kernel, the following vulnerability has been resolved:
usb: host: max3421: Fix shift-out-of-bounds in max3421_hub_control()
The `max3421_hub_control()` function handles USB hub class requests
to the virtual root hub. In the `default` branches of both the
`ClearPortFeature` and `SetPortFeature` switch statements, it modifies
`max3421_hcd->port_status` by left shifting 1 by the request's `value`
parameter. However, it does not validate whether this shift will exceed
the width of `port_status`.
So if a malicious userspace task with access to the root hub via
/dev/bus/usb/.../001 issues a USBDEVFS_CONTROL ioctl with `wValue`
greater than or equal to 32, the left shift operation invokes
shift-out-of-bounds undefined behavior. This results in arbitrary
bit corruption of `port_status`, including the normally-immutable
change bits, which can bypass internal state checks and confuse the
hub status.
Fix this by rejecting requests whose `value` exceeds the shift width
before performing the shift.
This issue was found using a KLEE-based symbolic execution tool for
kernel drivers that I'm currently developing.
References
- https://git.kernel.org/stable/c/00dd025324b56d39d37e57a08f473dab3a660f30 git.kernel.org
- https://git.kernel.org/stable/c/02d03c61e8a7b016956acb48e8a2512d16d87517 git.kernel.org
- https://git.kernel.org/stable/c/08b1d4cab0230697bc74c63fc4e40170a7559c54 git.kernel.org
- https://git.kernel.org/stable/c/3be5f24e8270ba53b3c814d13689bb8644c86237 git.kernel.org
- https://git.kernel.org/stable/c/4da073d57176d8e1c2bca34febfbc81d2560c1a5 git.kernel.org
- https://git.kernel.org/stable/c/cff06b03b530ae1fe8a13e93a7848f2130e00fb4 git.kernel.org
- https://git.kernel.org/stable/c/d512bdefd241b98f4d7bcb5bab5614a86411fad4 git.kernel.org
- https://git.kernel.org/stable/c/e5fa9d8f40746ec3447335c9642c03410f5fd3af git.kernel.org