CVE-2025-38448

usb: gadget: u_serial: Fix race condition in TTY wakeup

MEDIUM
4.7
CVSS Score
Published: July 25, 2025 at 03:27 PM UTC
Updated: June 17, 2026 at 09:16 AM UTC
2 products affected across 2 vendorsLinux KernelDebian Linux

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Severity
MEDIUM4.7
Exploit prediction
EPSS 0.1%

Description

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: u_serial: Fix race condition in TTY wakeup A race condition occurs when gs_start_io() calls either gs_start_rx() or gs_start_tx(), as those functions briefly drop the port_lock for usb_ep_queue(). This allows gs_close() and gserial_disconnect() to clear port.tty and port_usb, respectively. Use the null-safe TTY Port helper function to wake up TTY. Example CPU1: CPU2: gserial_connect() // lock gs_close() // await lock gs_start_rx() // unlock usb_ep_queue() gs_close() // lock, reset port.tty and unlock gs_start_rx() // lock tty_wakeup() // NPE

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

3.5 ≤ v < 5.10.2403.5 ≤ v < 5.15.1893.5 ≤ v < 5.4.2963.5 ≤ v < 6.1.1463.5 ≤ v < 6.12.393.5 ≤ v < 6.15.73.5 ≤ v < 6.163.5 ≤ v < 6.6.995.11 ≤ v < 5.15.1895.16 ≤ v < 6.1.1465.5 ≤ v < 5.10.2406.13 ≤ v < 6.15.76.2 ≤ v < 6.6.996.7 ≤ v < 6.12.393.535f95fd7f234d2b58803bab6f6ebd6bb988050a26.16 rc16.16 rc26.16 rc36.16 rc4
Vendor states this is fixed in 18d58a467ccf011078352d91b4d6a0108c7318e8 (fixed)
Vendor states this is fixed in a5012673d49788f16bb4e375b002d7743eb642d9 (fixed)
Vendor states this is fixed in abf3620cba68e0e51e5c21054ce4f925f75b3661 (fixed)
Vendor states this is fixed in c529c3730bd09115684644e26bf01ecbd7e2c2c9 (fixed)
Vendor states this is fixed in c6eb4a05af3d0ba3bc4e8159287722fb9abc6359 (fixed)
Vendor states this is fixed in c8c80a3a35c2e3488409de2d5376ef7e662a2bf5 (fixed)
Vendor states this is fixed in d43657b59f36e88289a6066f15bc9a80df5014eb (fixed)
Vendor states this is fixed in ee8d688e2ba558f3bb8ac225113740be5f335417 (fixed)
Vendor states this is fixed in 3.5 (unaffected)
Vendor states this is fixed in 5.10.240 (unaffected)
Vendor states this is fixed in 5.15.189 (unaffected)
Vendor states this is fixed in 5.4.296 (unaffected)
Vendor states this is fixed in 6.1.146 (unaffected)
Vendor states this is fixed in 6.12.39 (unaffected)
Vendor states this is fixed in 6.15.7 (unaffected)
Vendor states this is fixed in 6.16 (unaffected)
Vendor states this is fixed in 6.6.99 (unaffected)

References (10)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/18d58a467ccf011078352d91b4d6a0108c7318e8
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/a5012673d49788f16bb4e375b002d7743eb642d9
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/abf3620cba68e0e51e5c21054ce4f925f75b3661
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/c529c3730bd09115684644e26bf01ecbd7e2c2c9
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/c6eb4a05af3d0ba3bc4e8159287722fb9abc6359
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/c8c80a3a35c2e3488409de2d5376ef7e662a2bf5
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/d43657b59f36e88289a6066f15bc9a80df5014eb
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/ee8d688e2ba558f3bb8ac225113740be5f335417

CVSS

Attack Vector
LOCAL
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-362

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