{"id":"CVE-2026-79978","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-79978","generatedAt":"2026-10-28T03:38:57.909Z","title":"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.","description":"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.\n\nA 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.\n\nThe 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.","published":"2026-10-23T20:17:28.000Z","lastModified":"2026-10-26T13:52:22.000Z","status":"Awaiting Analysis","sourceIdentifier":"vulnerabilities@zephyrproject.org","cvss":{"version":"3.1","score":3.6,"severity":"LOW","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L"},"cwe":["CWE-787"],"affected":[],"epss":{"score":0.00091,"percentile":0.00468,"date":"2026-10-27","history":[{"date":"2026-10-24","score":0.00124,"percentile":0.01972}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.09%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-23T20:17:28.000Z","detail":{"score":"3.6","severity":"LOW","publishedAt":"2026-10-23T20:17:27.657Z"},"summary":"New CVE, low severity (CVSS 3.6)."}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/3451bb1e1e9165844060551164adb8a756e7b6b7","source":"vulnerabilities@zephyrproject.org"},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-4v56-r4qm-v964","source":"vulnerabilities@zephyrproject.org"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-79978","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}