In the Linux kernel, the following vulnerability has been resolved: PCI/ASPM: Disable ASPM on MFD function removal to avoid use-after-free Struct pcielinkstate->downstream is a pointer to the pcidev of function 0. Previously we retained that pointer when removing function 0, and subsequent ASPM policy changes dereferenced it, resulting in a use-after-free warning from KASAN, e.g.: # echo 1 > /sys/bus/pci/devices/0000:03:00.0/remove # echo powersave > /sys/module/pcieaspm/parameters/policy BUG: KASAN: slab-use-after-free in pcieconfigaspmlink+0x42d/0x500 Call Trace: kasanreport+0xae/0xe0 pcieconfigaspmlink+0x42d/0x500 pcieaspmsetpolicy+0x8e/0x1a0 paramattrstore+0x162/0x2c0 moduleattrstore+0x3e/0x80 PCIe spec r6.0, sec 7.5.3.7, recommends that software program the same ASPM Control value in all functions of multi-function devices. Disable ASPM and free the pcielinkstate when any child function is removed so we can discard the dangling pcielinkstate->downstream pointer and maintain the same ASPM Control configuration for all functions. [bhelgaas: commit log and comment]