CVE-2025-40117

In the Linux kernel, the following vulnerability has been resolved:

misc: pci_endpoint_test: Fix array underflow in pci_endpoint_test_ioctl()

Commit eefb83790a0d ("misc: pci_endpoint_test: Add doorbell test case") added NO_BAR (-1) to the pci_barno enum which, in practical terms, changes the enum from an unsigned int to a signed int. If the user passes a negative number in pci_endpoint_test_ioctl() then it results in an array underflow in pci_endpoint_test_bar().

This vulnerability does not affect Red Hat Enterprise Linux releases because the code changes introducing the signed BAR number enumeration into the PCI endpoint test framework are not present in shipped kernels. The affected driver is intended specifically for hardware validation of PCI endpoint devices rather than standard production workloads. Consequently, systems running supported Red Hat enterprise kernels are not exposed to this flaw.