CVE-2023-53446: linux kernel Use-After-Free — Fix

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]

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-416 Use After Free

Affected Products

Vendor	Product	Versions
linux	linux_kernel	4.11 — 5.4.251
linux	linux_kernel	5.5 — 5.10.188
linux	linux_kernel	5.11 — 5.15.121
linux	linux_kernel	5.16 — 6.1.39
linux	linux_kernel	6.2 — 6.3.13
linux	linux_kernel	6.4 — 6.4.4

References

Advisories & Patches

https://git.kernel.org/stable/c/4203722d51afe3d239e03f15cc73efdf023a7103 https://git.kernel.org/stable/c/456d8aa37d0f56fc9e985e812496e861dcd6f2f2 https://git.kernel.org/stable/c/666e7f9d60cee23077ea3e6331f6f8a19f7ea03f https://git.kernel.org/stable/c/7aecdd47910c51707696e8b0e045b9f88bd4230f https://git.kernel.org/stable/c/7badf4d6f49a358a01ab072bbff88d3ee886c33b https://git.kernel.org/stable/c/9856c0de49052174ab474113f4ba40c02aaee086 https://git.kernel.org/stable/c/d51d2eeae4ce54d542909c4d9d07bf371a78592c

Frequently Asked Questions

What is CVE-2023-53446? +

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] It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2023-53446? +

CVE-2023-53446 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2023-53446? +

CVE-2023-53446 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2023-53446? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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