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parport: Fix race between port and client registration

Type: advisorySource: Official CVE List1 source record

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.

Announced Source revision 1
Original source ↗

CVE-2026-63942

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-63942

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
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Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "6fa45a22689722dac9f0e90c0931d4b34b334ede",
        "lessThan": "f3378b0d7bd4605de89b083b2900788157a181cc",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6fa45a22689722dac9f0e90c0931d4b34b334ede",
        "lessThan": "290f515c5e3b3900bc2fe24f179999fd08d23bfa",
        "versionType": "git"
      },
      {
        "status": "affected",
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        "lessThan": "d16548be2ea5058227d79799e81dab61c9bca8ec",
        "versionType": "git"
      },
      {
        "status": "affected",
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        "lessThan": "15b1723c1472e802f9f7e69ae4e64f7dbf588848",
        "versionType": "git"
      },
      {
        "status": "affected",
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        "lessThan": "51026cff1f4f3b762a0b5a07c727bd59cef45320",
        "versionType": "git"
      },
      {
        "status": "affected",
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        "lessThan": "74d6aae1df45d3414178986be743f946988fddf6",
        "versionType": "git"
      },
      {
        "status": "affected",
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      },
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        "lessThan": "ef15ccbb3e8640a723c42ad90eaf81d66ae02017",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "drivers/parport/share.c",
      "include/linux/parport.h"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "4.2"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "4.2",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.10.259",
        "versionType": "semver",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.210",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.176",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.143",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.93",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.35",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.0.12",
        "versionType": "semver",
        "lessThanOrEqual": "7.0.*"
      },
      {
        "status": "unaffected",
        "version": "7.1",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "drivers/parport/share.c",
      "include/linux/parport.h"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-63942

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#40904 · Revision 1
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Publisher date
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