CVE-2026-64460 PCI/IOV: Skip VF Resizable BAR restore on read error
A Linux kernel bug causes an out-of-bounds array access when restoring PCI VF state after a device read error, leading to a system crash.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-64460?
CVE-2026-64460 is a high-severity vulnerability in Linux, published on 25 Jul 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:
PCI/IOV: Skip VF Resizable BAR restore on read error
sriov_restore_vf_rebar_state() uses the VF Resizable BAR Control register to decide how many VF BARs to restore (nbars) and which VF BAR each iteration addresses (bar_idx). bar_idx indexes into dev->sriov->barsz[], which has only PCI_SRIOV_NUM_BARS (6) entries.
When a device does not respond, config reads typically return PCI_ERROR_RESPONSE (~0). Both fields are 3 bits wide, so nbars and bar_idx both evaluate to 7. The barsz[] access then goes out of bounds. UBSAN reports this as:
UBSAN: array-index-out-of-bounds in drivers/pci/iov.c:948:51 index 7 is out of range for type 'resource_size_t [6]'
Observed on an NVIDIA RTX PRO 1000 GPU (GB207GLM) that stopped responding during a failed GC6 power state exit. The subsequent pci_restore_state() invoked sriov_restore_vf_rebar_state() while config reads returned 0xffffffff, triggering the splat.
Bail out if any VF Resizable BAR Control read returns PCI_ERROR_RESPONSE. No further VF BARs are touched, which is safe because a config read that returns PCI_ERROR_RESPONSE indicates the device is unreachable and restoration is pointless. This mirrors the guard in pci_restore_rebar_state().
Weakness: CWE-125
Which versions are affected by CVE-2026-64460?
How do I fix CVE-2026-64460?
Apply the vendor's patch.
Is CVE-2026-64460 being exploited?
There is no known exploitation of CVE-2026-64460 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-64460, DEBIAN-CVE-2026-64460, GHSA-4g8v-7hmf-pf24, ROOT-OS-UBUNTU-2204-CVE-2026-64460, UBUNTU-CVE-2026-64460.