CVE-2025-71132: Linux kernel · smc91x: fix broken irq-context in PREEMPT_RT
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.5 High · fixed in ef277ae121b3249c99994652210a326b52d527b0 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:30 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-06-10.
- Patch
- Available – fixed in ef277ae121b3249c99994652210a326b52d527b0, b6018d5c1a8f09d5efe4d6961d7ee45fdf3a7ce3, 6402078bd9d1ed46e79465e1faaa42e3458f8a33 +3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 14 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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AI-suggested
A fix is available and has been applied in the Linux kernel source. Users should update to a kernel version that includes the fix (commits ef277ae121b3249c99994652210a326b52d527b0 and others). No additional mitigation is required beyond applying the official patch.
Description
CVE-2025-71132 is a vulnerability in the Linux kernel's smc91x network driver when built with the PREEMPT_RT patch. The issue causes a kernel BUG due to improper IRQ context handling, leading to a workqueue leak and potential system instability or crash. The root cause is that smc_special_trylock() disables IRQs but smc_special_unlock() does not restore them correctly under PREEMPT_RT. This has been fixed by replacing smc_special_trylock() with spin_trylock_irqsave().
References
- git.kernel.org/stable/c/1c4cb705e733250d13243f6a69b8b5a92e39b9f6 (opens in a new tab)
- git.kernel.org/stable/c/9d222141b00156509d67d80c771fbefa92c43ace (opens in a new tab)
- git.kernel.org/stable/c/ef277ae121b3249c99994652210a326b52d527b0 (opens in a new tab)
- git.kernel.org/stable/c/36561b86cb2501647662cfaf91286dd6973804a6 (opens in a new tab)
- git.kernel.org/stable/c/b6018d5c1a8f09d5efe4d6961d7ee45fdf3a7ce3 (opens in a new tab)
- git.kernel.org/stable/c/6402078bd9d1ed46e79465e1faaa42e3458f8a33 (opens in a new tab)