CVE-2025-21776: Linux kernel · USB: hub: Ignore non-compliant devices with too many configs or interfaces
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 5 Nov 2026, 23:23 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- EPSS
- 0.2% chance of exploitation in 30 days – higher than 20% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 27 Feb 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
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.
References
- git.kernel.org/stable/c/49f077106fa07919a6a6dda99bb490dd1d1a8218 (opens in a new tab)
- git.kernel.org/stable/c/d343fe0fad5c1d689775f2dda24a85ce98e29566 (opens in a new tab)
- git.kernel.org/stable/c/d3a67adb365cdfdac4620daf38a82e57ca45806c (opens in a new tab)
- git.kernel.org/stable/c/c3720b04df84b5459050ae4e03ec7d545652f897 (opens in a new tab)
- git.kernel.org/stable/c/e905a0fca7bff0855d312c16f71e60e1773b393e (opens in a new tab)
- git.kernel.org/stable/c/62d8f4c5454dd39aded4f343720d1c5a1803cfef (opens in a new tab)
- git.kernel.org/stable/c/5b9778e1fe715700993ce436c152dc3b7df0b490 (opens in a new tab)
- git.kernel.org/stable/c/2240fed37afbcdb5e8b627bc7ad986891100e05d (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/05/msg00030.html (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/03/msg00028.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-265688.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-503939.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)