CVE-2026-98756 usb: cdns3: Fix NULL pointer dereference in cdns3_pci_probe
A NULL pointer dereference in the Linux kernel's Cadence USBSS driver can cause a system crash during device probing.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98756?
CVE-2026-98756 is a vulnerability in Linux, published on 18 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
usb: cdns3: Fix NULL pointer dereference in cdns3_pci_probe
The Cadence USBSS controller is a two-function PCI device. The first probed function allocates the driver data and stores it with pci_set_drvdata(), while the second function reuses it via pci_get_drvdata() when pci_is_enabled() reports that the first function has already been probed.
When the second function is probed while the first one has been enabled but has not yet set its driver data, pci_get_drvdata() returns NULL, and the subsequent wrap->devfn assignment dereferences a NULL pointer and crashes the kernel. logs: Call trace: cdns3_pci_probe+0xa4/0x300 local_pci_probe+0x44/0xa8 pci_call_probe+0x54/0x158 pci_device_probe+0x84/0x100 really_probe+0x184/0x3d0 __driver_probe_device+0x80/0x178 driver_probe_device+0x44/0xe8 __driver_attach+0xec/0x1f8 bus_for_each_dev+0x7c/0xe0 driver_attach+0x28/0x38 bus_add_driver+0x110/0x238 driver_register+0x64/0x128 __pci_register_driver+0x50/0x60 cdns3_pci_driver_init+0x28/0x38 do_one_initcall+0x5c/0x280 do_initcalls+0x104/0x1d8 kernel_init_freeable+0x140/0x218 kernel_init+0x28/0x1f8 ret_from_fork+0x10/0x20
Return -EPROBE_DEFER in this case so that probing is retried after the first function has completed its probe.
Which versions are affected by CVE-2026-98756?
How do I fix CVE-2026-98756?
Apply the vendor's patch.
Is CVE-2026-98756 being exploited?
There is no known exploitation of CVE-2026-98756 in the wild and no public exploit code.
Sources
Also known as AZL-108803, BELL-CVE-2026-98756, DEBIAN-CVE-2026-98756, GHSA-r25x-m228-w665, UBUNTU-CVE-2026-98756.