linux-kernel - Re: [PATCH v2] fs: binfmt_elf: Add ELF header consistency checks

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]

Date:	Thu, 21 Nov 2013 01:39:19 +0000
From:	Al Viro <viro@...IV.linux.org.uk>
To:	"Geyslan G. Bem" <geyslan@...il.com>
Cc:	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
	kernel-br@...glegroups.com
Subject: Re: [PATCH v2] fs: binfmt_elf: Add ELF header consistency checks

On Wed, Nov 20, 2013 at 09:34:31PM -0300, Geyslan G. Bem wrote:
> The member 'e_ehsize' that holds the ELF header size is compared
> with the elfhdr struct size. If not equal, goes out.
> If 'e_phoff' holds 0 the object has no program header table, so
> goes out.
> Ensures the file being loaded has the correct data encoding, checking
> 'e_ident[EI_DATA]' against 'ELF_DATA'.
> 
> Besides the checks being in accordance with the ELF Specifications,
> they increase the binary consistency reducing the use of malformed ones.

This is completely misguided.  We are allowed to reject such binaries,
but what's the point of doing that?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/