CVE-2026-63942

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.
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*

History

26 Oct 2026, 13:35

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/15b1723c1472e802f9f7e69ae4e64f7dbf588848 - () https://git.kernel.org/stable/c/15b1723c1472e802f9f7e69ae4e64f7dbf588848 - Patch
References () https://git.kernel.org/stable/c/290f515c5e3b3900bc2fe24f179999fd08d23bfa - () https://git.kernel.org/stable/c/290f515c5e3b3900bc2fe24f179999fd08d23bfa - Patch
References () https://git.kernel.org/stable/c/51026cff1f4f3b762a0b5a07c727bd59cef45320 - () https://git.kernel.org/stable/c/51026cff1f4f3b762a0b5a07c727bd59cef45320 - Patch
References () https://git.kernel.org/stable/c/74d6aae1df45d3414178986be743f946988fddf6 - () https://git.kernel.org/stable/c/74d6aae1df45d3414178986be743f946988fddf6 - Patch
References () https://git.kernel.org/stable/c/a1e81b58da0179531bedf0b9f2811f5f992d5c4b - () https://git.kernel.org/stable/c/a1e81b58da0179531bedf0b9f2811f5f992d5c4b - Patch
References () https://git.kernel.org/stable/c/d16548be2ea5058227d79799e81dab61c9bca8ec - () https://git.kernel.org/stable/c/d16548be2ea5058227d79799e81dab61c9bca8ec - Patch
References () https://git.kernel.org/stable/c/ef15ccbb3e8640a723c42ad90eaf81d66ae02017 - () https://git.kernel.org/stable/c/ef15ccbb3e8640a723c42ad90eaf81d66ae02017 - Patch
References () https://git.kernel.org/stable/c/f3378b0d7bd4605de89b083b2900788157a181cc - () https://git.kernel.org/stable/c/f3378b0d7bd4605de89b083b2900788157a181cc - Patch
CPE cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*
First Time Linux linux Kernel
Linux

19 Oct 2026, 21:17

Type Values Removed Values Added
CWE CWE-362

Information

Published : 2026-07-19 16:17

Updated : 2026-10-26 13:35


NVD link : CVE-2026-63942

Mitre link : CVE-2026-63942

CVE.ORG link : CVE-2026-63942


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-362

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')