CVE-2023-53446 PCI/ASPM: Disable ASPM on MFD function removal to avoid use-after-free
A use-after-free vulnerability in the Linux kernel's PCI/ASPM subsystem allows local attackers to cause a system crash by removing a PCI function and changing power policies.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-53446?
CVE-2023-53446 is a high-severity use after free vulnerability in Linux kernel, published on 18 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
PCI/ASPM: Disable ASPM on MFD function removal to avoid use-after-free
Struct pcie_link_state->downstream is a pointer to the pci_dev 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/pcie_aspm/parameters/policy
BUG: KASAN: slab-use-after-free in pcie_config_aspm_link+0x42d/0x500 Call Trace: kasan_report+0xae/0xe0 pcie_config_aspm_link+0x42d/0x500 pcie_aspm_set_policy+0x8e/0x1a0 param_attr_store+0x162/0x2c0 module_attr_store+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 pcie_link_state when any child function is removed so we can discard the dangling pcie_link_state->downstream pointer and maintain the same ASPM Control configuration for all functions.
[bhelgaas: commit log and comment]
Weakness: CWE-416
Which versions are affected by CVE-2023-53446?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53446?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2023-53446 being exploited?
There is no known exploitation of CVE-2023-53446 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-53446, DEBIAN-CVE-2023-53446, GHSA-62j3-36wr-4gw5, UBUNTU-CVE-2023-53446.