CVE-2025-39724

MEDIUM EPSS 5.3%
Published Sep 5, 20259mo ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Sep 5, 2025 9mo ago
Last Modified Jun 17, 2026 1w ago

Description

In the Linux kernel, the following vulnerability has been resolved: serial: 8250: fix panic due to PSLVERR When the PSLVERR_RESP_EN parameter is set to 1, the device generates an error response if an attempt is made to read an empty RBR (Receive Buffer Register) while the FIFO is enabled. In serial8250_do_startup(), calling serial_port_out(port, UART_LCR, UART_LCR_WLEN8) triggers dw8250_check_lcr(), which invokes dw8250_force_idle() and serial8250_clear_and_reinit_fifos(). The latter function enables the FIFO via serial_out(p, UART_FCR, p->fcr). Execution proceeds to the serial_port_in(port, UART_RX). This satisfies the PSLVERR trigger condition. When another CPU (e.g., using printk()) is accessing the UART (UART is busy), the current CPU fails the check (value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR) in dw8250_check_lcr(), causing it to enter dw8250_force_idle(). Put serial_port_out(port, UART_LCR, UART_LCR_WLEN8) under the port->lock to fix this issue. Panic backtrace: [ 0.442336] Oops - unknown exception [#1] [ 0.442343] epc : dw8250_serial_in32+0x1e/0x4a [ 0.442351] ra : serial8250_do_startup+0x2c8/0x88e ... [ 0.442416] console_on_rootfs+0x26/0x70

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
5.3% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Affected Products 9

VendorProductVersionRange
linuxlinux_kernel*≥3.10.48  –  <3.11
linuxlinux_kernel*≥3.12.24  –  <5.4.297
linuxlinux_kernel*≥5.5  –  <5.10.241
linuxlinux_kernel*≥5.11  –  <5.15.190
linuxlinux_kernel*≥5.16  –  <6.1.149
linuxlinux_kernel*≥6.2  –  <6.6.103
linuxlinux_kernel*≥6.7  –  <6.12.44
linuxlinux_kernel*≥6.13  –  <6.16.4
debiandebian_linux11.0any

References 12

  • cert-portal.siemens.com https://cert-portal.siemens.com/productcert/html/ssa-032379.html
  • cert-portal.siemens.com https://cert-portal.siemens.com/productcert/html/ssa-082556.html
  • git.kernel.org https://git.kernel.org/stable/c/0b882f00655afefbc7729c6b5aec86f7a5473a3d
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/38c0ea484dedb58cb3a4391229933e16be0d1031
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/68c4613e89f000e8198f9ace643082c697921c9f
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/7f8fdd4dbffc05982b96caf586f77a014b2a9353
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/8e2739478c164147d0774802008528d9e03fb802
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/b8ca8e3f75ede308b4d49a6ca5081460be01bdb5
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c826943abf473a3f7260fbadfad65e44db475460
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/cb7b3633ed749db8e56f475f43c960652cbd6882
    Patch
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
    Mailing ListThird Party Advisory
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
    Mailing ListThird Party Advisory

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/0b882f00655afefbc7729c6b5aec86f7a5473a3d
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/38c0ea484dedb58cb3a4391229933e16be0d1031
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/68c4613e89f000e8198f9ace643082c697921c9f
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/7f8fdd4dbffc05982b96caf586f77a014b2a9353
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/8e2739478c164147d0774802008528d9e03fb802
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/b8ca8e3f75ede308b4d49a6ca5081460be01bdb5
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c826943abf473a3f7260fbadfad65e44db475460
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/cb7b3633ed749db8e56f475f43c960652cbd6882
    Patch