CVE-2023-53363: linux kernel Use-After-Free — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: PCI: Fix use-after-free in pci_bus_release_domain_nr() Commit c14f7ccc9f5d ("PCI: Assign PCI domain IDs by ida_alloc()") introduced a use-after-free bug in the bus removal cleanup. The issue was found with kfence: [ 19.293351] BUG: KFENCE: use-after-free read in pci_bus_release_domain_nr+0x10/0x70 [ 19.302817] Use-after-free read at 0x000000007f3b80eb (in kfence-#115): [ 19.309677] pci_bus_release_domain_nr+0x10/0x70 [ 19.309691] dw_pcie_host_deinit+0x28/0x78 [ 19.309702] tegra_pcie_deinit_controller+0x1c/0x38 [pcie_tegra194] [ 19.309734] tegra_pcie_dw_probe+0x648/0xb28 [pcie_tegra194] [ 19.309752] platform_probe+0x90/0xd8 ... [ 19.311457] kfence-#115: 0x00000000063a155a-0x00000000ba698da8, size=1072, cache=kmalloc-2k [ 19.311469] allocated by task 96 on cpu 10 at 19.279323s: [ 19.311562] __kmem_cache_alloc_node+0x260/0x278 [ 19.311571] kmalloc_trace+0x24/0x30 [ 19.311580] pci_alloc_bus+0x24/0xa0 [ 19.311590] pci_register_host_bridge+0x48/0x4b8 [ 19.311601] pci_scan_root_bus_bridge+0xc0/0xe8 [ 19.311613] pci_host_probe+0x18/0xc0 [ 19.311623] dw_pcie_host_init+0x2c0/0x568 [ 19.311630] tegra_pcie_dw_probe+0x610/0xb28 [pcie_tegra194] [ 19.311647] platform_probe+0x90/0xd8 ... [ 19.311782] freed by task 96 on cpu 10 at 19.285833s: [ 19.311799] release_pcibus_dev+0x30/0x40 [ 19.311808] device_release+0x30/0x90 [ 19.311814] kobject_put+0xa8/0x120 [ 19.311832] device_unregister+0x20/0x30 [ 19.311839] pci_remove_bus+0x78/0x88 [ 19.311850] pci_remove_root_bus+0x5c/0x98 [ 19.311860] dw_pcie_host_deinit+0x28/0x78 [ 19.311866] tegra_pcie_deinit_controller+0x1c/0x38 [pcie_tegra194] [ 19.311883] tegra_pcie_dw_probe+0x648/0xb28 [pcie_tegra194] [ 19.311900] platform_probe+0x90/0xd8 ... [ 19.313579] CPU: 10 PID: 96 Comm: kworker/u24:2 Not tainted 6.2.0 #4 [ 19.320171] Hardware name: /, BIOS 1.0-d7fb19b 08/10/2022 [ 19.325852] Workqueue: events_unbound deferred_probe_work_func The stack trace is a bit misleading as dw_pcie_host_deinit() doesn't directly call pci_bus_release_domain_nr(). The issue turns out to be in pci_remove_root_bus() which first calls pci_remove_bus() which frees the struct pci_bus when its struct device is released. Then pci_bus_release_domain_nr() is called and accesses the freed struct pci_bus. Reordering these fixes the issue.

Is your site exposed to CVE-2023-53363?

Run a free security scan — no signup, results in seconds.

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	6.2 — 6.2.12
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/07a75c0050e59c50f038cc5f4e2a3258c8f8c9d0 https://git.kernel.org/stable/c/30ba2d09edb5ea857a1473ae3d820911347ada62 https://git.kernel.org/stable/c/52b0343c7d628f37b38e3279ba585526b850ad3b https://git.kernel.org/stable/c/ad367516b1c09317111255ecfbf5e42c33e31918 https://git.kernel.org/stable/c/fbf45385e3419b8698b5e0a434847072375cfec2

Frequently Asked Questions

What is CVE-2023-53363? +

In the Linux kernel, the following vulnerability has been resolved: PCI: Fix use-after-free in pci_bus_release_domain_nr() Commit c14f7ccc9f5d ("PCI: Assign PCI domain IDs by ida_alloc()") introduced a use-after-free bug in the bus removal cleanup. The issue was found with kfence: [ 19.293351] BUG: KFENCE: use-after-free read in pci_bus_release_domain_nr+0x10/0x70 [ 19.302817] Use-after-free read at 0x000000007f3b80eb (in kfence-#115): [ 19.309677] pci_bus_release_domain_nr+0x10/0x70 [ 19.309691] dw_pcie_host_deinit+0x28/0x78 [ 19.309702] tegra_pcie_deinit_controller+0x1c/0x38 [pcie_tegra194] [ 19.309734] tegra_pcie_dw_probe+0x648/0xb28 [pcie_tegra194] [ 19.309752] platform_probe+0x90/0xd8 ... [ 19.311457] kfence-#115: 0x00000000063a155a-0x00000000ba698da8, size=1072, cache=kmalloc-2k [ 19.311469] allocated by task 96 on cpu 10 at 19.279323s: [ 19.311562] __kmem_cache_alloc_node+0x260/0x278 [ 19.311571] kmalloc_trace+0x24/0x30 [ 19.311580] pci_alloc_bus+0x24/0xa0 [ 19.311590] pci_register_host_bridge+0x48/0x4b8 [ 19.311601] pci_scan_root_bus_bridge+0xc0/0xe8 [ 19.311613] pci_host_probe+0x18/0xc0 [ 19.311623] dw_pcie_host_init+0x2c0/0x568 [ 19.311630] tegra_pcie_dw_probe+0x610/0xb28 [pcie_tegra194] [ 19.311647] platform_probe+0x90/0xd8 ... [ 19.311782] freed by task 96 on cpu 10 at 19.285833s: [ 19.311799] release_pcibus_dev+0x30/0x40 [ 19.311808] device_release+0x30/0x90 [ 19.311814] kobject_put+0xa8/0x120 [ 19.311832] device_unregister+0x20/0x30 [ 19.311839] pci_remove_bus+0x78/0x88 [ 19.311850] pci_remove_root_bus+0x5c/0x98 [ 19.311860] dw_pcie_host_deinit+0x28/0x78 [ 19.311866] tegra_pcie_deinit_controller+0x1c/0x38 [pcie_tegra194] [ 19.311883] tegra_pcie_dw_probe+0x648/0xb28 [pcie_tegra194] [ 19.311900] platform_probe+0x90/0xd8 ... [ 19.313579] CPU: 10 PID: 96 Comm: kworker/u24:2 Not tainted 6.2.0 #4 [ 19.320171] Hardware name: /, BIOS 1.0-d7fb19b 08/10/2022 [ 19.325852] Workqueue: events_unbound deferred_probe_work_func The stack trace is a bit misleading as dw_pcie_host_deinit() doesn't directly call pci_bus_release_domain_nr(). The issue turns out to be in pci_remove_root_bus() which first calls pci_remove_bus() which frees the struct pci_bus when its struct device is released. Then pci_bus_release_domain_nr() is called and accesses the freed struct pci_bus. Reordering these fixes the issue. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2023-53363? +

CVE-2023-53363 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-2023-53363? +

CVE-2023-53363 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-2023-53363? +

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.

Related Vulnerabilities

CVE-2026-6040

A heap use-after-free existed when importing the blank-width characters of an ODF number format. A position value read from the …

CVE-2025-24898

rust-openssl is a set of OpenSSL bindings for the Rust programming language. In affected versions `ssl::select_next_proto` can return a slice …

CVE-2025-31115

XZ Utils provide a general-purpose data-compression library plus command-line tools. In XZ Utils 5.3.3alpha to 5.8.0, the multithreaded .xz decoder …

CVE-2025-31498

c-ares is an asynchronous resolver library. From 1.32.3 through 1.34.4, there is a use-after-free in read_answers() when process_answer() may re-enqueue …

CVE-2025-4516

There is an issue in CPython when using `bytes.decode("unicode_escape", error="ignore|replace")`. If you are not using the "unicode_escape" encoding or an …

CVE-2025-5991

There is a "Use After Free" vulnerability in Qt's QHttp2ProtocolHandler in the QtNetwork module. This only affects HTTP/2 handling, HTTP …

CVE-2023-53363