DEBIAN-CVE-2021-47454

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Source
https://security-tracker.debian.org/tracker/CVE-2021-47454
Import Source
https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47454.json
JSON Data
https://api.test.osv.dev/v1/vulns/DEBIAN-CVE-2021-47454
Upstream
Published
2024-05-22T07:15:10Z
Modified
2025-09-30T09:17:28.303482Z
Severity
  • 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
[none]
Details

In the Linux kernel, the following vulnerability has been resolved: powerpc/smp: do not decrement idle task preempt count in CPU offline With PREEMPTCOUNT=y, when a CPU is offlined and then onlined again, we get: BUG: scheduling while atomic: swapper/1/0/0x00000000 no locks held by swapper/1/0. CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.15.0-rc2+ #100 Call Trace: dumpstacklvl+0xac/0x108 _schedulebug+0xac/0xe0 _schedule+0xcf8/0x10d0 scheduleidle+0x3c/0x70 doidle+0x2d8/0x4a0 cpustartupentry+0x38/0x40 startsecondary+0x2ec/0x3a0 startsecondaryprolog+0x10/0x14 This is because powerpc's archcpuidledead() decrements the idle task's preempt count, for reasons explained in commit a7c2bb8279d2 ("powerpc: Re-enable preemption before cpudie()"), specifically "startsecondary() expects a preemptcount() of 0." However, since commit 2c669ef6979c ("powerpc/preempt: Don't touch the idle task's preemptcount during hotplug") and commit f1a0a376ca0c ("sched/core: Initialize the idle task with preemption disabled"), that justification no longer holds. The idle task isn't supposed to re-enable preemption, so remove the vestigial preempt_enable() from the CPU offline path. Tested with pseries and powernv in qemu, and pseries on PowerVM.

References

Affected packages

Debian:11 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
5.10.84-1

Affected versions

5.*

5.10.46-4
5.10.46-5
5.10.70-1~bpo10+1
5.10.70-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Debian:12 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
5.14.16-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Debian:13 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
5.14.16-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Debian:14 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
5.14.16-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}