CVE-2026-64460
NVD analysis in progress
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().
What this means
- Exposure
- Exploitable with local access to the machine, with an ordinary user account and with no action from the victim. The attack does require particular conditions, which makes it less systematic.
- Impact
- An attacker can read some data, alter some data and take the service offline. The impact spreads beyond the vulnerable component into other parts of the system.
- Likelihood
- Its EPSS score stays low: nothing points to imminent exploitation, which is no reason to leave it unpatched.
What to doFold into the next patch cycle.
Read automatically from the CVSS vector, the weakness type (CWE) and the EPSS score. The technical description above remains the one published by NIST.