Kernel crash via stale netfs dirty state
Published Jul 19, 2026 · Updated Jul 19, 2026
Denial of service in Linux Kernel allows local users to crash the kernel by truncating and memory-mapping a streamed netfs file. netfs_invalidate_folio() discards netfs_folio after truncation removes all dirty data but fails to clear the folio dirty bit, so netfs_read_gaps() later dereferences missing private state. Reachability requires a sufficiently large netfs-backed file, a streaming write with fscaching disabled, truncation that removes the dirty range, and a later mmap read.
Summary
What happened
Denial of service in Linux Kernel allows local users to crash the kernel by truncating and memory-mapping a streamed netfs file. netfs_invalidate_folio() discards netfs_folio after truncation removes all dirty data but fails to clear the folio dirty bit, so netfs_read_gaps() later dereferences missing private state. Reachability requires a sufficiently large netfs-backed file, a streaming write with fscaching disabled, truncation that removes the dirty range, and a later mmap read.
The record
- CVE
- CVE-2026-64064
- Published
- Jul 19, 2026
- Updated
- Jul 19, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 19, 2026CVE publishedPublication date reported by the CVE source.
- Jul 19, 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=6.8
- Affected versionversion=9ebff83e648148b9ece97d4e4890dd84ca54d6ce <156ac2ec2ee77c44c4eb7439d6d165247ba12247
- Affected versionversion=9ebff83e648148b9ece97d4e4890dd84ca54d6ce <31ba145faceb378fa01afcb8349e15ea7d95e542
- Affected versionversion=9ebff83e648148b9ece97d4e4890dd84ca54d6ce <65ae8717abf36202fef02260b64b781d2d44a9bf
- Affected versionversion=9ebff83e648148b9ece97d4e4890dd84ca54d6ce <fb6ec883b48b8789e5e690dcd440d2db941e840c
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Upstream xfs_io reproduction sequenceproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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