parport: Fix race between port and client registration

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-63942
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-19 16:17:12 UTC
Updated2026-07-20 15:16:57 UTC
DescriptionIn 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.

Risk And Classification

Primary CVSS: v3.1 7.8 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS: 0.002100000 probability, percentile 0.113680000 (date 2026-07-20)

VersionSourceTypeScoreSeverityVector
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 6fa45a22689722dac9f0e90c0931d4b34b334ede f3378b0d7bd4605de89b083b2900788157a181cc git Not specified
CNA Linux Linux affected 6fa45a22689722dac9f0e90c0931d4b34b334ede 290f515c5e3b3900bc2fe24f179999fd08d23bfa git Not specified
CNA Linux Linux affected 6fa45a22689722dac9f0e90c0931d4b34b334ede d16548be2ea5058227d79799e81dab61c9bca8ec git Not specified
CNA Linux Linux affected 6fa45a22689722dac9f0e90c0931d4b34b334ede 15b1723c1472e802f9f7e69ae4e64f7dbf588848 git Not specified
CNA Linux Linux affected 6fa45a22689722dac9f0e90c0931d4b34b334ede 51026cff1f4f3b762a0b5a07c727bd59cef45320 git Not specified
CNA Linux Linux affected 6fa45a22689722dac9f0e90c0931d4b34b334ede 74d6aae1df45d3414178986be743f946988fddf6 git Not specified
CNA Linux Linux affected 6fa45a22689722dac9f0e90c0931d4b34b334ede a1e81b58da0179531bedf0b9f2811f5f992d5c4b git Not specified
CNA Linux Linux affected 6fa45a22689722dac9f0e90c0931d4b34b334ede ef15ccbb3e8640a723c42ad90eaf81d66ae02017 git Not specified
CNA Linux Linux affected 4.2 Not specified
CNA Linux Linux unaffected 4.2 semver Not specified
CNA Linux Linux unaffected 5.10.259 5.10.* semver Not specified
CNA Linux Linux unaffected 5.15.210 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.176 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.143 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.93 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.35 6.18.* semver Not specified
CNA Linux Linux unaffected 7.0.12 7.0.* semver Not specified
CNA Linux Linux unaffected 7.1 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/a1e81b58da0179531bedf0b9f2811f5f992d5c4b 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/290f515c5e3b3900bc2fe24f179999fd08d23bfa 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/ef15ccbb3e8640a723c42ad90eaf81d66ae02017 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/d16548be2ea5058227d79799e81dab61c9bca8ec 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/74d6aae1df45d3414178986be743f946988fddf6 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/f3378b0d7bd4605de89b083b2900788157a181cc 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/15b1723c1472e802f9f7e69ae4e64f7dbf588848 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/51026cff1f4f3b762a0b5a07c727bd59cef45320 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
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