ZephyrProject Zephyr up to 4.4.x NXP GAU ADC Driver adc_mcux_gau_adc.c mcux_gau_adc_read_samples buffer_size buffer overflow

Summaryinfo

A vulnerability marked as problematic has been reported in ZephyrProject Zephyr up to 4.4.x. The affected element is the function mcux_gau_adc_read_samples of the file drivers/adc/adc_mcux_gau_adc.c of the component NXP GAU ADC Driver. Performing a manipulation of the argument buffer_size results in buffer overflow. This vulnerability is cataloged as CVE-2026-19184. The attack must be initiated from a local position. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in ZephyrProject Zephyr up to 4.4.x. It has been classified as problematic. This affects the function mcux_gau_adc_read_samples of the file drivers/adc/adc_mcux_gau_adc.c of the component NXP GAU ADC Driver. The manipulation of the argument buffer_size with an unknown input leads to a buffer overflow vulnerability. CWE is classifying the issue as CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. This is going to have an impact on integrity, and availability. The summary by CVE is:

The NXP GAU ADC driver (drivers/adc/adc_mcux_gau_adc.c) validated the caller-supplied sequence->buffer_size, which is expressed in bytes, against the number of active channels, which is a sample count. It then stored that byte count directly in data->results_length and used it in mcux_gau_adc_read_samples() as the number of uint16_t slots available. Because each conversion result occupies sizeof(uint16_t) bytes, a buffer that was accepted as "large enough" could be written with up to twice its size in bytes, so every sample past the buffer's midpoint was written out of bounds. adc_read() and adc_read_async() are Zephyr system calls. The syscall verifier in drivers/adc/adc_handlers.c only confirms that the caller owns buffer_size writable bytes (K_SYSCALL_MEMORY_WRITE); deciding whether that size is sufficient for the requested channels and extra_samplings is delegated entirely to the driver. On a build with CONFIG_USERSPACE=y, a user-mode thread that has been granted the ADC device object could therefore submit a deliberately half-sized buffer and cause the driver's work-queue handler — which runs in supervisor mode, outside the caller's MPU restrictions — to write ADC conversion results past the end of that buffer, at an address and for a length of the caller's choosing. The overrun is bounded by the requested sequence: with sequence->options->extra_samplings set, the sampling loop walks the buffer pointer forward across every sampling, so the total overrun can reach the full size of the supplied buffer (kilobytes for a large extra_samplings). The written words are 16-bit ADC conversion results, so the content is only partially attacker-influenced (via the selected analog input, gain and resolution), but the destination and length are fully controlled — sufficient for kernel memory corruption, a crash, or a userspace-to-kernel privilege escalation. Builds without CONFIG_USERSPACE, or on SoCs other than NXP RW61x with the GAU ADC node enabled, are not exposed to the privilege boundary; there the same defect only causes a silent overflow when the application itself passes an undersized buffer. The fix replaces the ad-hoc check with the shared adc_sequence_validate_buffer() helper (validating against num_channels * sizeof(uint16_t)), stores buffer_size / sizeof(uint16_t) in results_length, and corrects the loop bound to a post-decrement so exactly the available number of slots may be written.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-19184 since 08/06/2026. The exploitability is told to be easy. An attack has to be approached locally. Technical details are known, but no exploit is available.

Upgrading to version 4.5.0 eliminates this vulnerability. Applying the patch 82b11958065aa85f8644ddc318ff4a328d1443c8 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Project Management Software

Vendor

• ZephyrProject

Name

• Zephyr

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4

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CPE 2.2info

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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