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Date: Mon, 26 Feb 2024 18:23:15 -0800
From: Kees Cook <keescook@chromium.org>
To: Jan Bujak <j@exia.io>
Cc: Pedro Falcato <pedro.falcato@gmail.com>, ebiederm@xmission.com,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	viro@zeniv.linux.org.uk, brauner@kernel.org,
	linux-fsdevel@vger.kernel.org
Subject: Re: Recent-ish changes in binfmt_elf made my program segfault
Message-ID: <202402261821.F2812C9475@keescook>
References: <c7209e19-89c4-446a-b364-83100e30cc00@exia.io>
 <CAKbZUD2=W0Ng=rFVDn3UwSxtGQ5c13tRwkpqm54pPCJO0BraWA@mail.gmail.com>
 <f2ee9602-0a32-4f0c-a69b-274916abe27f@exia.io>
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On Tue, Jan 23, 2024 at 12:23:27AM +0900, Jan Bujak wrote:
> On 1/22/24 23:54, Pedro Falcato wrote:
> > Hi!
> > 
> > Where did you get that linker script?
> > 
> > FWIW, I catched this possible issue in review, and this was already
> > discussed (see my email and Eric's reply):
> > https://lore.kernel.org/all/CAKbZUD3E2if8Sncy+M2YKncc_Zh08-86W6U5wR0ZMazShxbHHA@mail.gmail.com/
> > 
> > This was my original testcase
> > (https://github.com/heatd/elf-bug-questionmark), which convinced the
> > loader to map .data over a cleared .bss. Your bug seems similar, but
> > does the inverse: maps .bss over .data.
> > 
> 
> I wrote the linker script myself from scratch.

Do you still need this addressed, or have you been able to adjust the
linker script? (I ask to try to assess the priority of needing to fix
this behavior change...)

-Kees

-- 
Kees Cook