CVE-2025-39724

Siemens ProductCERT Advisory SSA-082556

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

Metrics

Severity
none
no public PoC known
6.4 %
Low — this CVE sits in the lower 10% of all CVEs scored today.
0.2 %
Low — model estimates < 1% exploitation likelihood.
Published
2021-09-26 00:00 UTC

Affected operating systems

  • bsd

    freebsd / freebsd13.2

  • bsd

    freebsd / freebsd13.3

  • bsd

    freebsd / freebsd14.0

  • bsd

    freebsd / freebsd14.1

  • bsd

    netbsd / netbsd

  • linux

    almalinux / almalinux9.0

  • linux

    amazon / amazon_linux2023.0

  • linux

    amazon / amazon_linux

  • linux

    ubuntu / awsbionic

  • linux

    ubuntu / awsjammy

  • linux

    ubuntu / awsnoble

  • linux

    ubuntu / awsresolute

  • linux

    ubuntu / awsxenial

  • linux

    ubuntu / aws-6.8jammy

  • linux

    ubuntu / aws-hwexenial

  • linux

    ubuntu / azurejammy

  • linux

    ubuntu / azurenoble

  • linux

    ubuntu / azureresolute

  • linux

    ubuntu / azurexenial

  • linux

    ubuntu / azure-4.15bionic

  • linux

    suse / basesystem_module15

  • linux

    debian / debian_linux10.0

  • linux

    debian / debian_linux11.0

  • linux

    debian / debian_linux12.0

Affected products

Products and version ranges extracted from the vendor/CERT advisory. A range like „<4.14.6“ implies the update recommendation „upgrade to 4.14.6 or later“.

  • android

    :linux_kernel::0

  • android

    :linux_kernel:Kernel

  • arista

    cloudvision_agni2024.4.0 – 2025.2.2

  • arista

    cloudvision_portal2024.2.0 – 2026.1.0

  • arista

    velocloud_edge4.5.0 – 6.4.1

  • arista

    velocloud_gateway

  • arista

    velocloud_orchestrator

  • bitnami

    java-min1.9.0

  • bitnami

    varnish6.1.0

  • bitnami

    varnish7.4.0

  • Dell

    ECS3.8.1.0-3.8.1.7

  • Dell

    NetWorkervProxy 19.14

  • Dell

    PowerScale OneFSNode Firmware Package 14.1

  • Dell

    Secure Connect GatewayAppliance 5.32.00.18

  • Dell

    Secure Connect Gateway< 5.36.00.16

    fixed in 5.36.00.16

  • Dell

    Secure Connect GatewayAppliance <5.32.00.18

  • gnu

    glibc2.35 – 2.37

  • gnu

    glibc

  • gnupg

    libgcrypt1.11.0 – 1.11.3

  • gnupg

    libgcrypt1.12.0 – 1.12.2

  • gnupg

    libgcrypt1.8.8 – 1.10.4

  • hackage

    xz-clib5.6.3

  • hackage

    xz-clib5.6.4

  • hackage

    xz-clib5.8.0

References & sources

Linked CVEs

Show 291 more CVEs
IDCVE-2025-39724