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.

A flaw was found in the Linux kernel's `ad_sigma_delta` driver for analog-to-digital converters (ADCs). This vulnerability occurs when the Chip Select (CS) line, which controls communication with the ADC, remains asserted after a conversion or in an error state. This can prevent other devices on the Serial Peripheral Interface (SPI) bus from communicating, leading to a denial of service. Additionally, improper handling of the bus lock can allow concurrent access to the SPI bus, potentially causing system instability.

Red Hat Enterprise Linux 10 Not affected kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Not affected kernel Red Hat Enterprise Linux 8 Not affected kernel-rt Red Hat Enterprise Linux 9 Not affected kernel Red Hat Enterprise Linux 9 Not affected kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-64501 https://nvd.nist.gov/vuln/detail/CVE-2026-64501 https://lore.kernel.org/linux-cve-announce/2026072552-CVE-2026-64501-b29a@gregkh/T