CVE-2025-21820

Published Feb 27, 2025

Last updated 7 months ago

CVSS medium 5.5

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: tty: xilinx_uartps: split sysrq handling lockdep detects the following circular locking dependency: CPU 0 CPU 1 ========================== ============================ cdns_uart_isr() printk() uart_port_lock(port) console_lock() cdns_uart_console_write() if (!port->sysrq) uart_port_lock(port) uart_handle_break() port->sysrq = ... uart_handle_sysrq_char() printk() console_lock() The fixed commit attempts to avoid this situation by only taking the port lock in cdns_uart_console_write if port->sysrq unset. However, if (as shown above) cdns_uart_console_write runs before port->sysrq is set, then it will try to take the port lock anyway. This may result in a deadlock. Fix this by splitting sysrq handling into two parts. We use the prepare helper under the port lock and defer handling until we release the lock.
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Modified
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
CWE-667

Social media

Hype score
Not currently trending

  1. 🚨 CVE-2025-21820 ❓ 🏢 Linux - Linux 🏗️ 74ea66d4ca061a3cd4c0e924e51b60e924644852 🔗 https://t.co/lOZaWrMu0D 🔗 https://t.co/14YzbIimcP 🔗 https://t.co/tqG0zrDDU2 🔗 https://t.co/9IOF6kTMPa 🔗 https://t.co/o22TWzhjmU #CyberCron #VulnAlert @Linux https://t.co/CgQI5FLGCC

    @cybercronai

    1 Mar 2025

    29 Impressions

    0 Retweets

    1 Like

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    0 Replies

    1 Quote

Configurations

Related CVEs

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References

Sources include official advisories and independent security research.