Local kernel crash via u_serial TTY race
Published Jul 25, 2025 · Updated May 11, 2026
Affected Linux kernel releases starting with 3.5 allow local users to crash the kernel through a u_serial TTY wakeup race. gs_start_rx() and gs_start_tx() drop port_lock around usb_ep_queue(), permitting concurrent teardown to clear port.tty before tty_wakeup() dereferences it. Triggering requires local access to race USB gadget serial I/O against close or disconnect operations; the bounded consequence is an availability-only kernel crash.
Summary
What happened
Affected Linux kernel releases starting with 3.5 allow local users to crash the kernel through a u_serial TTY wakeup race. gs_start_rx() and gs_start_tx() drop port_lock around usb_ep_queue(), permitting concurrent teardown to clear port.tty before tty_wakeup() dereferences it. Triggering requires local access to race USB gadget serial I/O against close or disconnect operations; the bounded consequence is an availability-only kernel crash.
The record
- CVE
- CVE-2025-38448
- Published
- Jul 25, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-362, T1499
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 25, 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=3.5
- Affected versionversion=35f95fd7f234d2b58803bab6f6ebd6bb988050a2 <18d58a467ccf011078352d91b4d6a0108c7318e8
- Affected versionversion=35f95fd7f234d2b58803bab6f6ebd6bb988050a2 <a5012673d49788f16bb4e375b002d7743eb642d9
- Affected versionversion=35f95fd7f234d2b58803bab6f6ebd6bb988050a2 <abf3620cba68e0e51e5c21054ce4f925f75b3661
- Affected versionversion=35f95fd7f234d2b58803bab6f6ebd6bb988050a2 <c529c3730bd09115684644e26bf01ecbd7e2c2c9
- Affected versionversion=35f95fd7f234d2b58803bab6f6ebd6bb988050a2 <c6eb4a05af3d0ba3bc4e8159287722fb9abc6359
- Affected versionversion=35f95fd7f234d2b58803bab6f6ebd6bb988050a2 <c8c80a3a35c2e3488409de2d5376ef7e662a2bf5
- Affected versionversion=35f95fd7f234d2b58803bab6f6ebd6bb988050a2 <d43657b59f36e88289a6066f15bc9a80df5014eb
- Affected versionversion=35f95fd7f234d2b58803bab6f6ebd6bb988050a2 <ee8d688e2ba558f3bb8ac225113740be5f335417
What conditions does exploitation require?
What is affected?
Published CVSS scores
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
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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