Configuration Information [Automatically generated, do not change][RW: The
configuration info generated by bashbug is useless, as it is a cross build]:
Machine: x86_64
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS: -g -O2
uname output: Linux foxxylove 6.4.0-150600.23.47-default #1 SMP PREEMPT_DYNAMIC
Thu Apr 3 03:44:04 UTC 2025 (2854fd7) x86_64 x86_64 x86_64 GNU/Linux
Machine Type: x86_64-pc-linux-gnu
Bash Version: 5.2
Patch Level: 37
Release Status: release
Description:
getcwd() as implemented in lib/sh/getcwd.c can return with NULL and a
stale errno value if the algorithm fails. It aborts if readdir()
returns NULL and no matching directory entry was found.
But bash's getcwd() assumes that NULL from readdir() is always an error,
which is not the case.
This can happen on filesystems where d_ino != st_ino such as
on Linux's OverlayFS.
I have observed error messages like:
shell-init: error retrieving current directory: getcwd: cannot access
parent directories: Inappropriate ioctl for device
Or:
shell-init: error retrieving current directory: getcwd: cannot access
parent directories: Success
Repeat-By:
The problem happens when the bash getcwd() implementation is used and
the filesystem
has odd semantics regarding inode numbers reported by readdir() and
stat().
Such semantics can happen with OverayFS on Linux but also with many
other network or
userspace filesystems.
Fix:
I suggest as a fix setting errno to 0 before calling readdir() to
distinguish
between the error and end-of-directory case and setting errno to EINVAL
or such
if the algorithm is unable to determine the directory name.
