# CVE-2026-64501: iio: adc: ad\_sigma\_delta: fix CS held asserted and state leaks

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2026-07-25 · Updated: 2026-08-17

## Affected

- Linux: version range not reported
- Linux: 6.14

## Description

In the Linux kernel, the following vulnerability has been resolved: iio: adc: ad_sigma_delta: fix CS held asserted and state leaks In ad_sigma_delta_single_conversion(), set_mode(AD_SD_MODE_IDLE) and disable_one() were called from the out: block while keep_cs_asserted was still true. This caused any SPI transfer issued by those callbacks to carry cs_change=1, leaving CS permanently asserted after the conversion. Fix by moving both calls into the out_unlock: block, after keep_cs_asserted is cleared, matching the pattern already used in ad_sd_calibrate(). In the error path of ad_sd_buffer_postenable(), if an operation fails after set_mode(AD_SD_MODE_CONTINUOUS) has already succeeded (e.g. spi_offload_trigger_enable()), the device is left in continuous conversion mode with CS physically asserted. Additionally, bus_locked remaining true after spi_bus_unlock() causes subsequent SPI operations to call spi_sync_locked() without the bus lock actually held, allowing concurrent SPI access. Fix the error path by clearing keep_cs_asserted first, then calling set_mode(AD_SD_MODE_IDLE) to revert the device mode and deassert CS, then clearing bus_locked before releasing the bus. For devices that implement neither set_mode nor disable_one (such as MAX11205, which has no physical CS pin), no SPI transfer is issued during cleanup and the cs_change flag has no effect on any physical line.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
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## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/c313bb7c38855e94ceef939d152dd75e5a904b5f
- https://git.kernel.org/stable/c/f1de829ee87a1198d3465493ce430d36c5fa029c
- https://git.kernel.org/stable/c/c72da0688575e5ef39c36bb44fed53aa18f8ae65

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Page: https://cve.now/CVE-2026-64501
JSON: https://cve.now/api/v1/entries/CVE-2026-64501
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