Bug 2266594 (CVE-2021-47018) - CVE-2021-47018 kernel: ensure definition of the fixmap area is in a limit
Summary: CVE-2021-47018 kernel: ensure definition of the fixmap area is in a limit
Status: NEW
Alias: CVE-2021-47018
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Product Security
QA Contact:
Depends On: 2266596
Blocks: 2266587
TreeView+ depends on / blocked
Reported: 2024-02-28 12:44 UTC by Rohit Keshri
Modified: 2024-06-18 18:49 UTC (History)
50 users (show)

Fixed In Version:
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Doc Text:
A flaw was found in the Linux kernel. The fixmap area that was defined for the PPC64 architecture was invalid.
Clone Of:
Last Closed:

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Description Rohit Keshri 2024-02-28 12:44:08 UTC
In the Linux kernel, the following vulnerability has been resolved:

powerpc/64: Fix the definition of the fixmap area

At the time being, the fixmap area is defined at the top of
the address space or just below KASAN.

This definition is not valid for PPC64.

For PPC64, use the top of the I/O space.

Because of circular dependencies, it is not possible to include
asm/fixmap.h in asm/book3s/64/pgtable.h , so define a fixed size
AREA at the top of the I/O space for fixmap and ensure during
build that the size is big enough.


Comment 1 Rohit Keshri 2024-02-28 12:47:24 UTC
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2266596]

Comment 3 Justin M. Forbes 2024-02-28 18:49:50 UTC
This was fixed for Fedora with the 5.12.4 stable kernel update.

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