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().
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().
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
||||||||||||||||||
| Linux | Linux | affected |
|
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Advisories
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Fixes
Solution
No solution given by the vendor.
Workaround
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References
History
Sat, 25 Jul 2026 09:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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(). | |
| Title | PCI/IOV: Skip VF Resizable BAR restore on read error | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-07-25T08:51:27.568Z
Reserved: 2026-07-19T15:36:31.789Z
Link: CVE-2026-64460
Vulnrichment
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NVD
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Redhat
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OpenCVE Enrichment
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Weaknesses
No weakness.