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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2025-21820 Detail

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.


Metrics

 
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CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://git.kernel.org/stable/c/4410dba9807a17a93f649a9f5870ceaf30a675a3 kernel.org Patch 
https://git.kernel.org/stable/c/8ea0e7b3d7b8f2f0fc9db491ff22a0abe120801c kernel.org Patch 
https://git.kernel.org/stable/c/9b88a7c4584ba67267a051069b8abe44fc9595b2 kernel.org Patch 
https://git.kernel.org/stable/c/b06f388994500297bb91be60ffaf6825ecfd2afe kernel.org Patch 
https://git.kernel.org/stable/c/de5bd24197bd9ee37ec1e379a3d882bbd15c5065 kernel.org Patch 
https://git.kernel.org/stable/c/e22a97700901ba5e8bf8db68056a0d50f9440cae kernel.org
https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html CVE

Weakness Enumeration

CWE-ID CWE Name Source
CWE-667 Improper Locking cwe source acceptance level NIST  

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Change History

4 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2025-21820
NVD Published Date:
02/27/2025
NVD Last Modified:
11/03/2025
Source:
kernel.org