CVE-2026-79978

LowCVSS 3.6

Published: 23/10/2026(UTC)Updated: 02/11/2026(UTC)Translated: 23/10/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.09%

0th percentile - higher than 0% of all known CVEs

Summary

A vulnerability in the ADXL345 sensor driver (drivers/sensor/adi/adxl345/adxl345_stream.c) in Zephyr RTOS involves a buffer overflow during RTIO FIFO streaming. The driver clamps the reported data length to available buffer space but still queues one bus read per hardware FIFO entry, causing writes up to 186 bytes past the allocation when the buffer is smaller than a full batch. A companion defect leaves fifo_total_bytes un-reset at batch start, potentially carrying a stale write offset into the next batch.

Risk Assessment

A local workload can induce RTIO buffer-pool starvation, leading to silent corruption of other RTIO consumers' data or a system crash. Exploitation requires a board with an interrupt-wired ADXL345 built with CONFIG_ADXL345_STREAM; there is no network, USB, or radio path.

Recommendation

Update Zephyr RTOS to a version containing the ADXL345 driver fix, or restrict FIFO streaming with small mempool blocks until the patch is applied. Review RTIO_DEFINE_WITH_MEMPOOL configurations for sensors to ensure block sizes of at least a full FIFO batch (204 bytes).

Related vulnerabilities

Original NVD description (English source)

The RTIO streaming completion callback adxl345_process_fifo_samples_cb() in drivers/sensor/adi/adxl345/adxl345_stream.c clamps the amount of FIFO data it will report (read_len = MIN(fifo_bytes, buf_avail)) to the space actually returned by rtio_sqe_rx_buf(), but then queues one 6-byte bus read per hardware FIFO entry at consecutive offsets from read_buf, bounded by the device-reported entry count rather than by the clamp. When the allocated buffer is smaller than a full batch, the driver writes up to 186 bytes past the end of the allocation; a companion defect left data->fifo_total_bytes un-reset at batch start, so an aborted or errored chain could leave a stale write offset that pushes the next batch's writes out of bounds as well. A short buffer is an expected, first-class outcome of the RTIO allocator: rtio_block_pool_alloc() walks the requested size down one block at a time until a contiguous run is available, and the driver only demands sizeof(struct adxl345_fifo_data) + 6 bytes as its minimum. Any streaming configuration whose mempool block granularity is smaller than a full FIFO batch (204 bytes) — for example the sensor shell's RTIO_DEFINE_WITH_MEMPOOL(sensor_read_rtio, 8, 8, 32, 64, 4) used by sensor stream <dev> on fifo_wm incl, or the 16-byte-block streaming example in the documentation — takes this path whenever the pool is fragmented or the consuming thread falls behind. The out-of-bounds writes are performed by the I2C/SPI RTIO backend (DMA on many SoCs) into the shared RTIO block pool, corrupting neighbouring live buffers or, for a pool smaller than one batch, memory beyond the pool itself. The written bytes are accelerometer samples and the destination follows the allocation, so there is no controllable corruption primitive: the realistic impact is silent corruption of other RTIO consumers' data or a crash. Reaching it requires a board with an interrupt-wired ADXL345 built with CONFIG_ADXL345_STREAM, plus buffer-pool starvation, which a co-resident local workload can induce but which also occurs spontaneously under load; there is no network, USB or radio path to this code.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS