Kernel panic via dangling histogram variable
Published Sep 11, 2026 · Updated Sep 11, 2026
Use-after-free in Linux kernel tracing allows local users with tracefs write access to crash the system using same-name histogram triggers. The named-data branch of hist_register_trigger() frees duplicate hist_data without removing its tr->hist_vars entry, so find_var_file() later dereferences the dangling pointer. Writing the required three trigger definitions requires privileged tracefs access; the final write causes a kernel panic and service interruption.
Summary
What happened
Use-after-free in Linux kernel tracing allows local users with tracefs write access to crash the system using same-name histogram triggers. The named-data branch of hist_register_trigger() frees duplicate hist_data without removing its tr->hist_vars entry, so find_var_file() later dereferences the dangling pointer. Writing the required three trigger definitions requires privileged tracefs access; the final write causes a kernel panic and service interruption.
The record
- CVE
- CVE-2026-89746
- Published
- Sep 11, 2026
- Updated
- Sep 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Sep 11, 2026CVE publishedPublication date reported by the CVE source.
- Sep 11, 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=435d2964af815aae456db554c62963b4515f19d0 <477d762be4b0ffaf01429ccd88859e93b0ec28cc
- Affected versionversion=43b254d46c740bf9dbe65709afa021dd726dfa99
- Affected versionversion=5ae1b18f05ee2b849dc03b6c15d7da0c1c6efa77
- Affected versionversion=6.1.130 <6.2
- Affected versionversion=6.12.18 <6.12.109
- Affected versionversion=6.13.6 <6.14
- Affected versionversion=6.14
- Affected versionversion=6.6.81 <6.7
- Affected versionversion=6f86bdeab633a56d5c6dccf1a2c5989b6a5e323e <83d1ae0406d8eade219a81b401e201702dd9dc55
- Affected versionversion=6f86bdeab633a56d5c6dccf1a2c5989b6a5e323e <a7318172aa332a161fb9618286e64454c827f8fd
- Affected versionversion=6f86bdeab633a56d5c6dccf1a2c5989b6a5e323e <b1a49c22de01faf176d44e5caa765e237353a579
- Affected versionversion=f1ae50cfb818ce1ac7a674406dfadb7653e2552d
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
- Upstream tracefs histogram-trigger reproducerproof of concept · validated
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Technologies
Your stack
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Your stack
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