Re: Don't execute binary files if execve() returned ENOEXEC.

[Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>]

On Tue, Feb 07, 2017 at 09:33:07AM +0100, Adam Borowski wrote:
> Both "dash -c foo" and "./foo" are supposed to be able to run hashbang-less
> scripts, but attempts to execute common binary files tend to be nasty:
> especially both ELF and PE tend to make dash create a bunch of files with
> unprintable names, that in turn confuse some tools up to causing data loss.
> 
> Thus, let's read the first line and see if it looks like text.  This is a
> variant of the approach used by bash and zsh; mksh instead checks for
> signatures of a bunch of common file types.
> 
> POSIX says: "If the executable file is not a text file, the shell may bypass
> this command execution.".
> 
> Signed-off-by: Adam Borowski <kilobyte@xxxxxxxxxx>

I'm not going to apply this patch because

1) It's not required by POSIX.
2) As you said the detection is imperfect, both false positives
and false negatives can occur.

Cheers,
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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