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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-63942 Detail

Description

In the Linux kernel, the following vulnerability has been resolved: parport: Fix race between port and client registration The parport subsystem registers port devices before they are fully initialised, resulting in a race condition where client drivers such as lp can attach to ports that are not completely initialised or even being torn down. When the port and client drivers are built as modules and loaded around the same time during boot, this occasionally results in a crash. I was able to make this happen reliably in a VM with a PC-style parallel port by patching parport_pc to fail probing: > --- a/drivers/parport/parport_pc.c > +++ b/drivers/parport/parport_pc.c > @@ -2069,7 +2069,7 @@ static struct parport *__parport_pc_probe_port(unsigned long int base, > if (!p) > goto out3; > > - base_res = request_region(base, 3, p->name); > + base_res = NULL; > if (!base_res) > goto out4; > and then running: while true; do modprobe lp & modprobe parport_pc wait rmmod lp parport_pc done for a few seconds. In the long term I think port registration should be changed to put the call to device_add() inside parport_announce_port(), but since the latter currently cannot fail this will require changing all port drivers. For now, add a flag to indicate whether a port has been "announced" and only try to attach client drivers to ports when the flag is set.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

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

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URL Source(s) Tag(s)
https://git.kernel.org/stable/c/15b1723c1472e802f9f7e69ae4e64f7dbf588848 kernel.org
https://git.kernel.org/stable/c/290f515c5e3b3900bc2fe24f179999fd08d23bfa kernel.org
https://git.kernel.org/stable/c/51026cff1f4f3b762a0b5a07c727bd59cef45320 kernel.org
https://git.kernel.org/stable/c/74d6aae1df45d3414178986be743f946988fddf6 kernel.org
https://git.kernel.org/stable/c/a1e81b58da0179531bedf0b9f2811f5f992d5c4b kernel.org
https://git.kernel.org/stable/c/d16548be2ea5058227d79799e81dab61c9bca8ec kernel.org
https://git.kernel.org/stable/c/ef15ccbb3e8640a723c42ad90eaf81d66ae02017 kernel.org
https://git.kernel.org/stable/c/f3378b0d7bd4605de89b083b2900788157a181cc kernel.org

Weakness Enumeration

CWE-ID CWE Name Source

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-63942
NVD Published Date:
07/19/2026
NVD Last Modified:
07/20/2026
Source:
kernel.org