CVE-2025-39724

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Source
https://cve.org/CVERecord?id=CVE-2025-39724
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-39724.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2025-39724
Downstream
Related
Published
2025-09-05T17:21:32.005Z
Modified
2026-03-20T12:43:01.026623Z
Summary
serial: 8250: fix panic due to PSLVERR
Details

In the Linux kernel, the following vulnerability has been resolved:

serial: 8250: fix panic due to PSLVERR

When the PSLVERRRESPEN 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 serial8250dostartup(), calling serialportout(port, UARTLCR, UARTLCRWLEN8) triggers dw8250checklcr(), which invokes dw8250forceidle() and serial8250clearandreinitfifos(). The latter function enables the FIFO via serialout(p, UARTFCR, p->fcr). Execution proceeds to the serialportin(port, UARTRX). 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 & ~UARTLCRSPAR) == (lcr & ~UARTLCRSPAR) in dw8250checklcr(), causing it to enter dw8250forceidle().

Put serialportout(port, UARTLCR, UARTLCR_WLEN8) under the port->lock to fix this issue.

Panic backtrace: [ 0.442336] Oops - unknown exception [#1] [ 0.442343] epc : dw8250serialin32+0x1e/0x4a [ 0.442351] ra : serial8250dostartup+0x2c8/0x88e ... [ 0.442416] consoleonrootfs+0x26/0x70

Database specific 
{
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39724.json"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
c49436b657d0a56a6ad90d14a7c3041add7cf64d
Fixed
0b882f00655afefbc7729c6b5aec86f7a5473a3d
Fixed
b8ca8e3f75ede308b4d49a6ca5081460be01bdb5
Fixed
68c4613e89f000e8198f9ace643082c697921c9f
Fixed
c826943abf473a3f7260fbadfad65e44db475460
Fixed
cb7b3633ed749db8e56f475f43c960652cbd6882
Fixed
8e2739478c164147d0774802008528d9e03fb802
Fixed
38c0ea484dedb58cb3a4391229933e16be0d1031
Fixed
7f8fdd4dbffc05982b96caf586f77a014b2a9353
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Last affected
6d5e79331417886196cb3a733bdb6645ba85bc42
Last affected
2401577586898b3590db80f8b97a26f81f0f6d4e

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-39724.json"