CVE-2026-53044 Overview
CVE-2026-53044 affects the Linux kernel soc/tegra Control Backbone (CBB) driver. The vulnerability stems from incorrect ARRAY_SIZE usage in the fabric lookup tables. During target timeout lookup operations, the driver can perform an out-of-bounds read past the intended array boundary.
Upstream maintainers resolved the issue in three stable kernel commits: 499f7e5, 5c009a5, and f46870b. The flaw is specific to NVIDIA Tegra system-on-chip platforms where the CBB driver handles fabric error reporting.
Critical Impact
Out-of-bounds memory access in a kernel driver can produce information disclosure, kernel memory corruption, or denial of service on affected Tegra-based systems.
Affected Products
- Linux kernel soc/tegra CBB driver prior to commits 499f7e5, 5c009a5, and f46870b
- NVIDIA Tegra SoC platforms using the Control Backbone fabric error driver
- Downstream distributions shipping affected kernel versions
Discovery Timeline
- 2026-06-24 - CVE-2026-53044 published to NVD
- 2026-06-24 - Last updated in NVD database
Technical Details for CVE-2026-53044
Vulnerability Analysis
The vulnerability resides in the NVIDIA Tegra Control Backbone (CBB) driver located under drivers/soc/tegra/cbb. The driver maintains lookup tables that map fabric target identifiers to human-readable error and timeout information. These tables are indexed during error handling when the hardware reports a target timeout.
The defect arises from incorrect use of the ARRAY_SIZE macro against the fabric lookup tables. The bound used during iteration or index validation does not match the actual size of the table being accessed. As a result, code paths handling target timeout lookups can read past the end of the intended buffer.
This condition maps to an out-of-bounds read [CWE-125]. Kernel out-of-bounds access can leak adjacent memory contents into error log paths, trigger oops conditions, or destabilize the running kernel depending on adjacent memory layout.
Root Cause
The root cause is a mismatch between the ARRAY_SIZE value applied during iteration and the actual element count of the fabric lookup table referenced. The bounds check therefore permits indices that exceed the valid range of the target lookup array.
Attack Vector
The vulnerable code path executes during fabric error processing on Tegra hardware. Triggering the condition requires generating CBB target timeout events that exercise the affected lookup. Exploitability depends on whether an unprivileged actor can induce the relevant hardware error condition on a given platform.
No verified code examples or proof-of-concept exploits are available. See the upstream patches referenced below for the precise corrected bounds.
Detection Methods for CVE-2026-53044
Indicators of Compromise
- Unexpected kernel oops, warning, or panic messages referencing tegra_cbb, tegra234_cbb, or fabric target timeout handlers in dmesg
- KASAN reports flagging out-of-bounds reads inside Tegra CBB error handling functions
- Repeated fabric timeout errors followed by malformed target name strings in kernel logs
Detection Strategies
- Inventory running kernel versions on Tegra-based devices and compare against the fixed commits 499f7e5, 5c009a5, and f46870b
- Enable KASAN on test kernels to surface out-of-bounds accesses during fabric error workloads
- Monitor kernel ring buffer output for malformed strings or pointer values emitted by CBB error paths
Monitoring Recommendations
- Forward kernel logs from Tegra-based systems to a centralized logging or SIEM platform for review of CBB-related anomalies
- Alert on kernel panics or oops events on embedded Tegra fleets where such events are otherwise rare
- Track distribution security advisories for the Linux kernel package versions deployed in the environment
How to Mitigate CVE-2026-53044
Immediate Actions Required
- Identify systems running affected Linux kernel versions on NVIDIA Tegra hardware
- Apply the upstream stable kernel updates that incorporate commits 499f7e5, 5c009a5, and f46870b
- Reboot affected devices to load the patched kernel image
Patch Information
The fix is available in upstream Linux stable kernels via three commits: Kernel Git Commit 499f7e5, Kernel Git Commit 5c009a5, and Kernel Git Commit f46870b. Apply the kernel update provided by your Linux distribution once it integrates these stable patches.
Workarounds
- No vendor-supplied workaround is documented; updating the kernel is the supported remediation
- On systems where the CBB driver is built as a module and not required, consider not loading tegra_cbb until a patched kernel is deployed
- Restrict physical and local administrative access on Tegra devices that cannot be patched immediately
# Verify the running kernel version on a Tegra device
uname -r
# Check whether the tegra_cbb module is currently loaded
lsmod | grep -i tegra_cbb
# Review recent kernel messages from the CBB driver
dmesg | grep -iE 'tegra.*cbb|fabric'
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
