CVE-2026-53045 Overview
CVE-2026-53045 is a Linux kernel vulnerability in the tegra124-emc memory controller driver. The driver contained reversed logic when checking whether a specified memory timing enables the Delay-Locked Loop (DLL) via the Extended Mode Register Set (EMRS) register. DLL is enabled when bit A0 is low, but the original code interpreted the bit incorrectly, causing the driver to apply the wrong DLL state during memory timing transitions on Tegra124 platforms.
Critical Impact
Incorrect DLL configuration during EMC frequency transitions can lead to memory subsystem instability on NVIDIA Tegra124-based systems running affected Linux kernel versions.
Affected Products
- Linux kernel drivers/memory/tegra/tegra124-emc.c
- NVIDIA Tegra124 SoC platforms using the upstream EMC driver
- Multiple stable kernel branches (see referenced git commits)
Discovery Timeline
- 2026-06-24 - CVE-2026-53045 published to NVD
- 2026-06-24 - Last updated in NVD database
Technical Details for CVE-2026-53045
Vulnerability Analysis
The vulnerability resides in the External Memory Controller (EMC) driver for the NVIDIA Tegra124 SoC. The tegra124-emc driver manages DRAM frequency scaling and must correctly determine whether a target memory timing requires the DDR DLL to be enabled or disabled. The decision is encoded in bit A0 of the EMRS register, where a low bit indicates DLL enabled and a high bit indicates DLL disabled.
The driver's dll_change check inverted this semantic. As a result, the driver took the DLL-enable code path when the timing requested DLL disabled, and vice versa. During frequency transitions, this caused incorrect sequencing of memory training and DLL programming, which can produce unstable DRAM access on affected hardware.
Root Cause
The root cause is reversed boolean logic when interpreting the EMRS A0 bit. Because DLL is enabled when A0 is 0 rather than 1, the comparison must check for the low state. The fix inverts the conditional so dll_change reflects the correct intended DLL state from the timing table.
Attack Vector
This issue is a hardware-correctness defect rather than a remotely exploitable flaw. Triggering it requires the kernel to perform EMC frequency transitions on Tegra124 hardware, which is a local, privileged operation tied to the platform's DVFS path. There is no known remote attack vector, no public proof-of-concept, and no exploitation reported. The EPSS data reflects a very low likelihood of exploitation activity.
The vulnerability manifests in the EMC timing transition path on Tegra124 platforms. See the referenced kernel commits for the exact patch diff.
Detection Methods for CVE-2026-53045
Indicators of Compromise
- No known indicators of compromise. The defect produces memory subsystem misbehavior rather than attacker-controlled artifacts.
- Unexplained DRAM-related kernel errors or instability on Tegra124 platforms during CPU/memory frequency scaling may correlate with the bug.
Detection Strategies
- Inventory Linux hosts and embedded devices running on NVIDIA Tegra124 SoCs and identify the kernel version in use.
- Compare deployed kernel commits against the fixed commits referenced in the kernel.org stable tree.
- Review build configurations to determine whether CONFIG_TEGRA124_EMC is enabled in shipped images.
Monitoring Recommendations
- Collect dmesg and kernel logs from Tegra124 devices to detect EMC-related warnings during frequency transitions.
- Track kernel package versions across embedded fleets and alert on devices running pre-patch builds.
- Monitor device stability metrics (reboots, watchdog resets) on Tegra124 platforms as a proxy for memory-related faults.
How to Mitigate CVE-2026-53045
Immediate Actions Required
- Update affected Linux kernels to a version that includes the tegra124-emc: Fix dll_change check patch.
- Rebuild and redeploy firmware images for Tegra124-based embedded devices using a patched stable kernel branch.
- Validate memory stability after upgrade through standard board bring-up and stress tests.
Patch Information
The fix was merged into the mainline Linux kernel and backported to multiple stable branches. Reference commits include 05f138f, 1793249, 1ebbbef, 2369b18, 7e19e72, 9597ab9, a859673, and db0ae80.
Workarounds
- Where patching is not immediately feasible, restrict EMC frequency scaling by pinning the memory controller to a known-stable operating point in device tree or platform configuration.
- Disable CONFIG_TEGRA124_EMC in custom kernel builds for deployments that do not require dynamic EMC scaling, accepting the performance trade-off.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
