bug#22354: Hash-bang line length

[Ludovic Courtès]

Greg Wooledge <address@hidden> skribis:

> On Wed, Jan 13, 2016 at 11:25:03AM +0100, Ludovic Courtès wrote:
>> Hello,
>> 
>> The ???READ_SAMPLE_BUF??? macro in execute_cmd.c reads at most 80 bytes from
>> the hash-bang line.  This is less than the already-small 128-byte limit
>> in the Linux kernel¹ and can quite easily be hit².
>
> That's actually much bigger than one expects for shebang handling on
> any traditional Unix system.

Sure, but the fact that it’s smaller than that of the kernel Linux is
problematic: when a hash-bang line > 127 chars is encountered, ‘execve’
fails with ENOENT, so Bash’s fallback code is executed, fails as well,
but it prints a misleading error message with an even more truncated
hash-bang line.

Ludo’.