Re: Broken elf header incorrectly identified as missing file

On Fri, Apr 17, 2026 at 2:22 PM Oliver Kiddle <[email protected]> wrote:
>
> Nathan wrote:
> > On zsh 5.9 (x86_64-ubuntu-linux-gnu)
> >
> > To reproduce:
> > 1. Create a malformed elf binary by deleting everything past part way through
> > the file (a broken binary that triggers the bug is attached)
> > 2. Make the binary executable
> > 3. Attempt to run the binary with ./b.out
> > 4. Observe that the file is incorrectly identified as not existing, when the
> > actual issue is a broken elf header
>
> It is not the job of the shell to dig in to malformed binaries. We pass
> it on to the operating system and system loader and error handling is
> their job.
>
> > Bash returns the correct error message, but several other shells return the
> > same wrong error.
>
> Probably because bash does go poking around in ELF binaries. This was
> proposed (and rejected) also for zsh, see:
>
> zsh-workers/34909 or https://www.zsh.org/mla/workers/2015/msg00833.html
>
> I've not examined the attached binary as such. If there are ways to get
> better errors just from the OS APIs then let us know. Not all systems
> zsh runs on use ELF.

And if the file is not readable, this won't work anyway, so even the
corner case has a corner case.