CVE-2026-53051

What the bug is

When PERST# is deasserted twice (assert -> deassert -> assert -> deassert), a CBB (Control Backbone) timeout occurs at DBI register offset 0x8bc (PCIE_MISC_CONTROL_1_OFF). This happens because pci_epc_deinit_notify() and dw_pcie_ep_cleanup() are called before reset_control_deassert() powers on the controller core. The call chain that causes the timeout: pex_ep_event_pex_rst_deassert() pci_epc_deinit_notify() pci_epf_test_epc_deinit() pci_epf_test_clear_bar() pci_epc_clear_bar() dw_pcie_ep_clear_bar() __dw_pcie_ep_reset_bar() dw_pcie_dbi_ro_wr_en() <- Accesses 0x8bc DBI register reset_control_deassert(pcie->core_rst) <- Core powered on HERE The DBI registers, including PCIE_MISC_CONTROL_1_OFF (0x8bc), are only accessible after the controller core is powered on via reset_control_deassert(pcie->core_rst). Accessing them before this point results in a CBB timeout because the hardware is not yet operational. Fix this by moving pci_epc_deinit_notify() and dw_pcie_ep_cleanup() to after reset_control_deassert(pcie->core_rst), ensuring the controller is fully powered on before any DBI register accesses occur.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

drivers/pci/controller/dwc/pcie-tegra194.c

What this is

PCI NATIVE HOST BRIDGE AND ENDPOINT DRIVERSMAINTAINERS section matched on drivers/pci/controller/ · linux-pci@vger.kernel.org · Supported

Kernel module

none to look for. The file would have gone into pcie_tegra194, and Debian does not compile it into that module, so finding pcie_tegra194 in lsmod would say nothing about this CVE.

Check it on the machine

grep -w CONFIG_PCIE_TEGRA194 /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

Show whether Debian builds this, per release

Debian does not build this code. In 4 releases below, every kernel flavour Debian publishes has the switch off, so the vulnerable file is compiled into no kernel binary Debian ships.

• bookworm, trixie, forky, sidn

n

not enabled on any flavour - this release does not build the code

Build switch

CONFIG_PCIE_TEGRA194

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-06-24 (4 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.16%, higher than 5.0% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

drivers/pci

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
6.12.2	6.12.91	010983063a80
6.13	6.18.33	b059a41bdd5b
6.13	7.0.10	ce899f9c0195
6.13	7.1	34b3eef48d98
6.11.11	0	0