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bounds: Use the right number of bits for power-of-two CONFIG_NR_CPUS

Steve Best requested to merge sfbest/centos-stream-9:37368 into main

JIRA: https://issues.redhat.com/browse/RHEL-37368
CVE: CVE-2024-35983

Build Info: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=61347638
Tested: Successful sanity booted on Intel systems.

commit 5af385f5f4cddf908f663974847a4083b2ff2c79
Author: Matthew Wilcox (Oracle) willy@infradead.org
Date: Mon Apr 29 15:47:51 2024 +0100

bounds: Use the right number of bits for power-of-two CONFIG_NR_CPUS  

bits_per() rounds up to the next power of two when passed a power of  
two.  This causes crashes on some machines and configurations.  

Reported-by: Михаил Новоселов <m.novosyolov@rosalinux.ru>  
Tested-by: Ильфат Гаптрахманов <i.gaptrakhmanov@rosalinux.ru>  
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/3347  
Link: https://lore.kernel.org/all/1c978cf1-2934-4e66-e4b3-e81b04cb3571@rosalinux.ru/  
Fixes: f2d5dcb48f7b (bounds: support non-power-of-two CONFIG_NR_CPUS)  
Cc:  <stable@vger.kernel.org>  
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>  
Cc: Rik van Riel <riel@surriel.com>  
Cc: Mel Gorman <mgorman@techsingularity.net>  
Cc: Peter Zijlstra <peterz@infradead.org>  
Cc: Ingo Molnar <mingo@kernel.org>  
Cc: Andrew Morton <akpm@linux-foundation.org>  
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Steve Best sbest@redhat.com

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