Kernel crash via stale tracer option write
Published Jul 25, 2026 · Updated Jul 25, 2026
NULL pointer dereference in Linux Kernel 6.19 allows local users with tracefs write access to crash the kernel through a stale option file. func_set_flag() reads tr->current_trace_flags before confirming that the active tracer is the function tracer, so a tracer switch can leave the pointer NULL. A process must keep a function-tracer option file open, switch to a non-function tracer, and then write the option; the resulting NULL dereference crashes the host.
Summary
What happened
NULL pointer dereference in Linux Kernel 6.19 allows local users with tracefs write access to crash the kernel through a stale option file. func_set_flag() reads tr->current_trace_flags before confirming that the active tracer is the function tracer, so a tracer switch can leave the pointer NULL. A process must keep a function-tracer option file open, switch to a non-function tracer, and then write the option; the resulting NULL dereference crashes the host.
The record
- CVE
- CVE-2026-64451
- Published
- Jul 25, 2026
- Updated
- Jul 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 25, 2026CVE publishedPublication date reported by the CVE source.
- Jul 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.19
- Affected versionversion=76680d0d2825900f23bf35290ab2b80bdf3a8e4a <69f17ac132a38974cf1defb480cef6b79d1ab768
- Affected versionversion=76680d0d2825900f23bf35290ab2b80bdf3a8e4a <c3e94604675e3db186111b8942650d86577df9b0
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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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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