HIGH
pci DomainNr DoubleFree
CVE-2026-43097
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
KernelScan AI2.9LOW
01Description
In the Linux kernel, the following vulnerability has been resolved: PCI: hv: Fix double ida_free in hv_pci_probe error path If hv_pci_probe() fails after storing the domain number in hbus->bridge->domain_nr, there is a call to free this domain_nr via pci_bus_release_emul_domain_nr(), however, during cleanup, the bridge release callback pci_release_host_bridge_dev() also frees the domain_nr causing ida_free to be called on same ID twice and triggering following warning: ida_free called for id=28971 which is not allocated. WARNING: lib/idr.c:594 at ida_free+0xdf/0x160, CPU#0: kworker/0:2/198 Call Trace: pci_bus_release_emul_domain_nr+0x17/0x20 pci_release_host_bridge_dev+0x4b/0x60 device_release+0x3b/0xa0 kobject_put+0x8e/0x220 devm_pci_alloc_host_bridge_release+0xe/0x20 devres_release_all+0x9a/0xd0 device_unbind_cleanup+0x12/0xa0 really_probe+0x1c5/0x3f0 vmbus_add_channel_work+0x135/0x1a0 Fix this by letting pci core handle the free domain_nr and remove the explicit free called in pci-hyperv driver.
02KernelScan AI Analysis
Risk summary
Hyper-V guest VMs with PCI passthrough may experience kernel warnings during device probe failures. The double-free of PCI domain numbers causes warning messages but does not crash the system or compromise security.
Vulnerability analysis
The vulnerability occurs in the Hyper-V PCI driver's error handling path where both the driver's explicit cleanup and the PCI core's automatic cleanup attempt to free the same domain number ID. This happens when hv_pci_probe() fails after storing the domain number but before successful completion. The fix removes the explicit cleanup call, allowing only the PCI core to handle domain number cleanup, eliminating the double-free condition. Attack surface is limited to Hyper-V guest VMs during PCI device probing.
03Fix Versions
| Branch | Fixed in | Patch commit |
|---|---|---|
| 6.19 | 6.19.14 | 21bc8e0ba5c2 |
| mainline | 7.0 | b6422dff0e51 |