linux-kernel - Re: Recent-ish changes in binfmt

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

Message-ID: <f2ee9602-0a32-4f0c-a69b-274916abe27f@exia.io>
Date: Tue, 23 Jan 2024 00:23:27 +0900
From: Jan Bujak <j@...a.io>
To: Pedro Falcato <pedro.falcato@...il.com>
Cc: ebiederm@...ssion.com, keescook@...omium.org, linux-mm@...ck.org,
 linux-kernel@...r.kernel.org, viro@...iv.linux.org.uk, brauner@...nel.org,
 linux-fsdevel@...r.kernel.org
Subject: Re: Recent-ish changes in binfmt_elf made my program segfault

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.

Thank you for the link to the previous discussion. So assuming this
breakage was intended my question here is - doesn't this run afoul
of the "we do not break userspace" rule?