Local kernel compromise via ISM teardown use-after-free
Published Aug 22, 2026 · Updated Aug 25, 2026
Use-after-free in affected Linux kernels allows local users to compromise the kernel during s390 ISM device teardown. During ism_dev_exit(), unregister_ieq() stops new interrupts, but teardown frees the sba and ieq DMA buffers before free_irq() drains handlers already using them. Reachability requires IBM Z ISM with SMC-D activity concurrent with privileged module unload, sysfs unbind, or hot-unplug; the dangling kernel access enables disclosure, memory corruption, privilege escalation, or a panic.
Summary
What happened
Use-after-free in affected Linux kernels allows local users to compromise the kernel during s390 ISM device teardown. During ism_dev_exit(), unregister_ieq() stops new interrupts, but teardown frees the sba and ieq DMA buffers before free_irq() drains handlers already using them. Reachability requires IBM Z ISM with SMC-D activity concurrent with privileged module unload, sysfs unbind, or hot-unplug; the dangling kernel access enables disclosure, memory corruption, privilege escalation, or a panic.
The record
- CVE
- CVE-2026-74690
- Published
- Aug 22, 2026
- Updated
- Aug 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 22, 2026CVE publishedPublication date reported by the CVE source.
- Aug 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=4.19
- Affected versionversion=684b89bc39ce4f204b1a2b180f39f2eb36a6b695 <774394d27930ec4cf4cb3eed8ab6a4d20cb2430a
- Affected versionversion=684b89bc39ce4f204b1a2b180f39f2eb36a6b695 <b1896543ce59c4258625a35cf41e23a9a1f80ea2
- Affected versionversion=684b89bc39ce4f204b1a2b180f39f2eb36a6b695 <fc3021284050ecb3bba8a7851340cedcb5037928
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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