CVE-2026-23287irqchip/sifive-plic: Fix frozen interrupt due to affinity setting
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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In the Linux kernel, the following vulnerability has been resolved: irqchip/sifive-plic: Fix frozen interrupt due to affinity setting PLIC ignores interrupt completion message for disabled interrupt, explained by the specification: The PLIC signals it has completed executing an interrupt handler by writing the interrupt ID it received from the claim to the claim/complete register. The PLIC does not check whether the completion ID is the same as the last claim ID for that target. If the completion ID does not match an interrupt source that is currently enabled for the target, the completion is silently ignored. This caused problems in the past, because an interrupt can be disabled while still being handled and plic_irq_eoi() had no effect. That was fixed by checking if the interrupt is disabled, and if so enable it, before sending the completion message. That check is done with irqd_irq_disabled(). However, that is not sufficient because the enable bit for the handling hart can be zero despite irqd_irq_disabled(d) being false. This can happen when affinity setting is changed while a hart is still handling the interrupt. This problem is easily reproducible by dumping a large file to uart (which generates lots of interrupts) and at the same time keep changing the uart interrupt's affinity setting. The uart port becomes frozen almost instantaneously. Fix this by checking PLIC's enable bit instead of irqd_irq_disabled().
- CVSS
- 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Modified
- Record last updated
- Oct 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from cc9f04f9a84f745949e325661550ed14bd0ff322 before 8942fb1a5bc2dcbd88f7e656d109d42f778f298f; from cc9f04f9a84f745949e325661550ed14bd0ff322 before 2edbd173309165d103be6c73bd83e459dc45ae7b; from cc9f04f9a84f745949e325661550ed14bd0ff322 before 686eb378a4a51aa967e08337dd59daade16aec0f; from cc9f04f9a84f745949e325661550ed14bd0ff322 before 1883332bf21feb8871af09daf604fc4836a76925; from cc9f04f9a84f745949e325661550ed14bd0ff322 before f611791a927141d05d7030607dea6372311c1413; from cc9f04f9a84f745949e325661550ed14bd0ff322 before 1072020685f4b81f6efad3b412cdae0bd62bb043 | CNA record |
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.6 | CISA ADP |
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name) | from V3.1.6 | CISA ADP |
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.6 | CISA ADP |
linux linux_kernel linux:linux_kernel | from 5.1 before 6.1.167; from 6.2 before 6.6.130; from 6.7 before 6.12.77; from 6.13 before 6.18.17; from 6.19 before 6.19.7; 7.0 | NVD |
References
- https://git.kernel.org/stable/c/8942fb1a5bc2dcbd88f7e656d109d42f778f298fpatch
- https://git.kernel.org/stable/c/2edbd173309165d103be6c73bd83e459dc45ae7bpatch
- https://git.kernel.org/stable/c/686eb378a4a51aa967e08337dd59daade16aec0fpatch
- https://git.kernel.org/stable/c/1883332bf21feb8871af09daf604fc4836a76925patch
- https://git.kernel.org/stable/c/f611791a927141d05d7030607dea6372311c1413patch
- https://git.kernel.org/stable/c/1072020685f4b81f6efad3b412cdae0bd62bb043patch
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.