2.5 KiB
CVE-2024-58093
Description
In the Linux kernel, the following vulnerability has been resolved:PCI/ASPM: Fix link state exit during switch upstream function removalBefore 456d8aa37d0f ("PCI/ASPM: Disable ASPM on MFD function removal toavoid use-after-free"), we would free the ASPM link only after the lastfunction on the bus pertaining to the given link was removed.That was too late. If function 0 is removed before sibling function,link->downstream would point to free'd memory after.After above change, we freed the ASPM parent link state upon any functionremoval on the bus pertaining to a given link.That is too early. If the link is to a PCIe switch with MFD on the upstreamport, then removing functions other than 0 first would free a link whichstill remains parent_link to the remaining downstream ports.The resulting GPFs are especially frequent during hot-unplug, becausepciehp removes devices on the link bus in reverse order.On that switch, function 0 is the virtual P2P bridge to the internal bus.Free exactly when function 0 is removed -- before the parent link isobsolete, but after all subordinate links are gone.[kwilczynski: commit log]
POC
Reference
No PoCs from references.