Linux KernelOperating system · Linux
CVE-2026-53051
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn the Linux kernel, the following vulnerability has been resolved: PCI: tegra194: Fix CBB timeout caused by DBI access before core power-on 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA race condition in the Linux kernel's PCI tegra194 driver causes CBB (Control Backbone) timeouts when PERST# is deasserted twice. DBI register accesses at offset 0x8bc occur in pci_epf_test_clear_bar() before reset_control_deassert() powers on the controller core, violating the hardware requirement that DBI registers are only accessible after core power-on.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Linux KernelOperating system
>= 6.11.11, < 6.12>= 6.12.2, < 6.12.91>= 6.13, < 6.18.33>= 6.19, < 7.0.10CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check your Linux kernel versionRun 'uname -r' to get the running kernel version, or 'cat /proc/version'Affected if The kernel version falls within any of these ranges: >= 6.11.11 and < 6.12; >= 6.12.2 and < 6.12.91; >= 6.13 and < 6.18.33; >= 6.19 and < 7.0.10
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Identify if the system uses Tegra194 hardwareCheck /proc/device-tree/compatible for 'nvidia,tegra194' or run 'lspci | grep -i nvidia' to list NVIDIA PCI devices, or check dmesg for 'tegra194' mentionsAffected if The system is running on NVIDIA Tegra194 SoC hardware and uses its PCIe controller
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Verify the PCIe driver is loadedRun 'lsmod | grep -i pcie' or check 'modinfo pcie_tegra194' to see if the Tegra194 PCIe driver is loadedAffected if The pcie_tegra194 or dw_pcie_ep driver module is loaded and managing a PCIe controller on Tegra194
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Check if PCIe endpoint functionality is in useReview system configuration for PCIe endpoint use cases (e.g., check /sys/bus/pci/drivers for endpoint bindings, or check dmesg for 'pci_epc' or 'pcie_ep' initialization messages)Affected if The system configures or uses PCIe endpoint functionality on the Tegra194 controller (the vulnerable code path runs during EP initialization/teardown)
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Inspect the driver source code directlyIf you have access to the driver source, examine drivers/pci/controller/dwc/pcie-tegra194.c for the ordering of pci_epc_deinit_notify() or dw_pcie_ep_cleanup() calls relative to reset_control_deassert(pcie->core_rst)Affected if The cleanup functions are called before reset_control_deassert() is invoked (indicating the unpatched vulnerable state)
You are affected if you are running a vulnerable kernel version on Tegra194 hardware with the PCIe endpoint driver active, where DBI register access occurs before the controller is powered on.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped6.126.12.916.18.33
This kernel bug requires updating to the patched Linux kernel version. Users should apply the kernel update that moves pci_epc_deinit_notify() and dw_pcie_ep_cleanup() to after reset_control_deassert(pcie->core_rst).
Linux kernel >= 7.0.10 or >= 6.18.33 (whichever is the first stable release containing the fix)
- Upgrade the Linux kernel to a version that includes the fix for the PCI: tegra194 CBB timeout issue
- The fix moves pci_epc_deinit_notify() and dw_pcie_ep_cleanup() calls to after reset_control_deassert(pcie->core_rst) in the tegra194 PCIe endpoint driver
- Verify the fix is present in the kernel source by checking the tegra194_pcie_ep_reset_init() or equivalent function in the PCIe endpoint code
- After upgrade, test PCIe endpoint functionality, specifically testing PERST# assertion/deassertion sequences
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Linux Kernel
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing8.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-53051 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-53051 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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