From: Andrew Morton <akpm@linux-foundation.org>
To: Helge Deller <deller@gmx.de>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>,
linux-mm@kvack.org, linux-parisc@vger.kernel.org
Subject: Re: [PATCH] usercopy: Do not fail on memory from former init sections
Date: Fri, 7 Jan 2022 15:44:30 -0800 [thread overview]
Message-ID: <20220107154430.1bd6252e66baada7d84bdd6c@linux-foundation.org> (raw)
In-Reply-To: <YdeHDDAP+TY5wNeT@ls3530>
On Fri, 7 Jan 2022 01:19:24 +0100 Helge Deller <deller@gmx.de> wrote:
> On some platforms the memory area between the _stext and the _etext
> symbols includes the init sections (parisc and csky). If the init
> sections are freed after bootup, the kernel may reuse this memory.
>
> In one test the usercopy checks if the given address is inside the .text
> section (from _stext to _etext), and it wrongly fails on the mentioned
> platforms if the memory is from the former init section.
>
> Fix this failure by first checking against the init sections before
> checking against the _stext/_etext section.
This sounds like it might have very serious runtime effects?
Please always fully describe a bug's runtime effects when fixing that bug.
> Fixes: 98400ad75e95 ("parisc: Fix backtrace to always include init funtion names")
So is this a must-have for 5.16?
next parent reply other threads:[~2022-01-07 23:44 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <YdeHDDAP+TY5wNeT@ls3530>
2022-01-07 23:44 ` Andrew Morton [this message]
2022-01-07 23:46 ` Andrew Morton
2022-01-07 23:51 ` Andrew Morton
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