Host panic via exFAT cleanup double free
Published Jul 4, 2025 · Updated Sep 2, 2026
Double free in the Linux kernel exFAT driver causes a host panic under panic_on_warn during cleanup of a failed filesystem mount. When exfat_load_default_upcase_table fails with ENOMEM, exfat_free_upcase_table frees vol_utbl but leaves its pointer non-NULL, so delayed_free frees it again during exfat_kill_sb cleanup. Reaching this path requires CAP_SYS_ADMIN in the initial user namespace and an ENOMEM condition outside attacker control, so reliable attacker-triggered interruption is not established.
Summary
What happened
Double free in the Linux kernel exFAT driver causes a host panic under panic_on_warn during cleanup of a failed filesystem mount. When exfat_load_default_upcase_table fails with ENOMEM, exfat_free_upcase_table frees vol_utbl but leaves its pointer non-NULL, so delayed_free frees it again during exfat_kill_sb cleanup. Reaching this path requires CAP_SYS_ADMIN in the initial user namespace and an ENOMEM condition outside attacker control, so reliable attacker-triggered interruption is not established.
The record
- CVE
- CVE-2025-38206
- Published
- Jul 4, 2025
- Updated
- Sep 2, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Jul 4, 2025CVE publishedPublication date reported by the CVE source.
- Sep 2, 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=1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 <13d8de1b6568dcc31a95534ced16bc0c9a67bc15
- Affected versionversion=1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 <1f3d9724e16d62c7d42c67d6613b8512f2887c22
- Affected versionversion=1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 <29abaf93357f4a7d083cf399d4306999e20db31d
- Affected versionversion=1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 <66e84439ec2af776ce749e8540f8fdd257774152
- Affected versionversion=1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 <ac65f76db9b2ff3fbc9e198c0e9aaf81b111b7d0
- Affected versionversion=1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 <d3cef0e7a5c1aa6217c51faa9ce8ecac35d6e1fd
- Affected versionversion=1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 <ea27703eb0efbadcd45b9949526160ed90536a72
- Affected versionversion=5.7
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What is affected?
Published CVSS scores
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Attacks
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Technologies
Your stack
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