Updated: 2025-11-03 02:59:58.382469
Description:
In the Linux kernel, the following vulnerability has been resolved: PCI/ASPM: Fix link state exit during switch upstream function removal Before 456d8aa37d0f ("PCI/ASPM: Disable ASPM on MFD function removal to avoid use-after-free"), we would free the ASPM link only after the last function 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 function removal on the bus pertaining to a given link. That is too early. If the link is to a PCIe switch with MFD on the upstream port, then removing functions other than 0 first would free a link which still remains parent_link to the remaining downstream ports. The resulting GPFs are especially frequent during hot-unplug, because pciehp 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 Free exactly when function 0 is removed -- before the parent link is obsolete, but after all subordinate links are gone. [kwilczynski: commit log]
| Links | NIST | CIRCL | RHEL | Ubuntu |
| Severity | Score | |
|---|---|---|
| CVSS Version 2.x | 0.0 | |
| CVSS Version 3.x | HIGH | 7.8 |
| OS name | Project name | Version | Score | Severity | Status | Errata | Last updated | Statement |
|---|---|---|---|---|---|---|---|---|
| Oracle Linux 7 ELS | kernel-uek | 5.4.17 | 7.8 | HIGH | Released | CLSA-2025:1757963029 | 2025-09-16 11:21:12 | |
| Ubuntu 18.04 ELS | linux | 4.15.0 | 7.8 | HIGH | Already Fixed | 2025-11-11 14:43:17 | ||
| Ubuntu 20.04 ELS | linux | 5.4.0 | 7.8 | HIGH | Already Fixed | 2025-11-11 14:43:10 |