Kernel crash via stale KUnit log pointer
Published Jan 8, 2025 · Updated May 11, 2026
Use-after-free in KUnit string-stream setup in Linux 6.7 through 6.12.3 allows local users to crash the kernel during test-suite initialization. When alloc_string_stream() fails in kunit_debugfs_create_suite(), the error path frees suite->log without clearing it, and kunit_init_suite() later passes the dangling pointer to string_stream_clear(). Reachability requires local KUnit test-suite initialization and an allocation failure; the demonstrated result is an Oops followed by a fatal kernel panic.
Summary
What happened
Use-after-free in KUnit string-stream setup in Linux 6.7 through 6.12.3 allows local users to crash the kernel during test-suite initialization. When alloc_string_stream() fails in kunit_debugfs_create_suite(), the error path frees suite->log without clearing it, and kunit_init_suite() later passes the dangling pointer to string_stream_clear(). Reachability requires local KUnit test-suite initialization and an allocation failure; the demonstrated result is an Oops followed by a fatal kernel panic.
The record
- CVE
- CVE-2024-56772
- Published
- Jan 8, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-416, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 8, 2025CVE publishedPublication date reported by the CVE source.
- May 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=6.7
- Affected versionversion=a3fdf784780ccb0008d630e8722d1389c49c7499 <3213b92754b94dec6836e8b4d6ec7d224a805b61
- Affected versionversion=a3fdf784780ccb0008d630e8722d1389c49c7499 <39e21403c978862846fa68b7f6d06f9cca235194
What conditions does exploitation require?
What is affected?
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.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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