CVE-2025-39724

serial: 8250: fix panic due to PSLVERR

MEDIUM 5.5

At a glance

Source
NVD
EPSS
EPSS 0.17 % · percentile 7 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified

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

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · nvd@nist.gov (Primary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected c49436b657d0a56a6ad90d14a7c3041add7cf64d < 0b882f00655afefbc7729c6b5aec86f7a5473a3d ; affected c49436b657d0a56a6ad90d14a7c3041add7cf64d < b8ca8e3f75ede308b4d49a6ca5081460be01bdb5 ; affected c49436b657d0a56a6ad90d14a7c3041add7cf64d < 68c4613e89f000e8198f9ace643082c697921c9f ; affected c49436b657d0a56a6ad90d14a7c3041add7cf64d < c826943abf473a3f7260fbadfad65e44db475460 ; affected c49436b657d0a56a6ad90d14a7c3041add7cf64d < cb7b3633ed749db8e56f475f43c960652cbd6882 ; affected c49436b657d0a56a6ad90d14a7c3041add7cf64d < 8e2739478c164147d0774802008528d9e03fb802
Linux · Linuxaffected 3.13 ; unaffected 0 < 3.13 ; unaffected 5.4.297 ≤ 5.4.* ; unaffected 5.10.241 ≤ 5.10.* ; unaffected 5.15.190 ≤ 5.15.* ; unaffected 6.1.149 ≤ 6.1.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD