linux-kernel - linux-6.19-rc8/kernel/liveupdate/kexec_handover.c:1089: Possible 32/64 bit mixup ?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID:
 <VI1PR02MB3952964EF347629B2686A36E9C99A@VI1PR02MB3952.eurprd02.prod.outlook.com>
Date: Thu, 5 Feb 2026 09:21:17 +0000
From: David Binderman <dcb314@...mail.com>
To: "graf@...zon.com" <graf@...zon.com>, "rppt@...nel.org" <rppt@...nel.org>,
	"pasha.tatashin@...een.com" <pasha.tatashin@...een.com>,
	"pratyush@...nel.org" <pratyush@...nel.org>, "kexec@...ts.infradead.org"
	<kexec@...ts.infradead.org>, "linux-mm@...ck.org" <linux-mm@...ck.org>, LKML
	<linux-kernel@...r.kernel.org>
Subject: linux-6.19-rc8/kernel/liveupdate/kexec_handover.c:1089: Possible
 32/64 bit mixup ?

Hello there,

Source code analyser cppcheck says:

linux-6.19-rc8/kernel/liveupdate/kexec_handover.c:1089:15: style: int result is assigned to long variable. If the variable is long to avoid loss of information, then you have loss of information. [truncLongCastAssignment]

Source code is

    contig_pages = (1 << order);

I admit the error message is hard to understand, but AFAIK
if local variable order remains under 30 or so, then there is no problem.

However, if it goes above 32, then there will be loss of data. 
Expression 1 << order is type int.

Suggest add some code or comment to document the expected range
of local variable order. If it ever goes above 32, suggest new code

    contig_pages = 1UL << order;

Regards

David Binderman