From: Szabolcs Nagy <nsz@port70.net>
To: Norbert Lange <nolange79@gmail.com>
Cc: musl@lists.openwall.com
Subject: Re: [musl] Mark stack as non-executable in asm
Date: Wed, 10 Jun 2020 12:31:02 +0200 [thread overview]
Message-ID: <20200610103102.GF871552@port70.net> (raw)
In-Reply-To: <CADYdroN+CxoPihWQtAR7rOM9A9cDtUr9a9RzP4SrG7d6G1gv0A@mail.gmail.com>
* Norbert Lange <nolange79@gmail.com> [2020-06-10 11:24:04 +0200]:
> I did borrow some assembler files to avoid having to link against
> (any) libc. That was for building a DSO, ultimately loaded via glibc.
> The effect was that glibc did change the protection of all stacks to
> be executable.
>
> Would you consider adding the line [1]
> .section .note.GNU-stack, "", %progbits
> to assembly files?
>
> I know this is not a musl bug, and I can easily add the lines myself.
musl build system (just like other libcs i know of)
pass -noexecstack to the assembler so if you build
the asm files as part of libc the object files should
have the marking, if you build outside of libc i
think it's your responsibility to add the note
(either to the asm or via the -Wa,-noexecstack flag)
readelf -lW libfoo.so | grep GNU_STACK
is one way to verify that everything has the note.
>
> regards, Norbert
>
> [1] - https://wiki.ubuntu.com/SecurityTeam/Roadmap/ExecutableStacks
next prev parent reply other threads:[~2020-06-10 10:31 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-10 9:24 Norbert Lange
2020-06-10 10:31 ` Szabolcs Nagy [this message]
2020-06-10 10:39 ` Jeffrey Walton
2020-06-10 10:43 ` Norbert Lange
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