Bug 2309799 (CVE-2024-44968) - CVE-2024-44968 kernel: tick/broadcast: Move per CPU pointer access into the atomic section
Summary: CVE-2024-44968 kernel: tick/broadcast: Move per CPU pointer access into the a...
Keywords:
Status: NEW
Alias: CVE-2024-44968
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On: 2309818
Blocks:
TreeView+ depends on / blocked
 
Reported: 2024-09-04 19:21 UTC by OSIDB Bzimport
Modified: 2024-09-04 21:10 UTC (History)
4 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2024-09-04 19:21:20 UTC
In the Linux kernel, the following vulnerability has been resolved:

tick/broadcast: Move per CPU pointer access into the atomic section

The recent fix for making the take over of the broadcast timer more
reliable retrieves a per CPU pointer in preemptible context.

This went unnoticed as compilers hoist the access into the non-preemptible
region where the pointer is actually used. But of course it's valid that
the compiler keeps it at the place where the code puts it which rightfully
triggers:

  BUG: using smp_processor_id() in preemptible [00000000] code:
       caller is hotplug_cpu__broadcast_tick_pull+0x1c/0xc0

Move it to the actual usage site which is in a non-preemptible region.


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