May be somewhat related to #167 , /etc/profile is supposed to be read if bash is a login shell - but even bash.exe --login doesn't seem to use pam_umask

@simonbuchan Thanks for reporting this. I think there are a couple things going on here. I verified that when bash.exe --login is launched /bin/bash does read from /etc/profile. I dumped my default /etc/profile and noticed a comment that:

# The default umask is now handled by pam_umask.
# See pam_umask(8) and /etc/login.defs.

When you run "bash.exe --login" that translates into "/bin/bash --login". We don't run the /bin/login binary and I'm assuming that's what normally sets up pam_umask. Did you try adding a new umask to value to your /etc/profile? It should work (when using bash.exe --login).

Yep, umask in both /etc/profile and ~/.profile run with both bash.exe --login and bash -c "bash --login".
Interestingly, if I revert the umask command and do bash.exe -c "sudo login" then umask is 0002 - no idea where that is coming from!

Please ensure umask is never 0000 no matter how bash is started.

I understand users can set umask to saner defaults in their own bashrc files but it means whatever directories and files auto-installed by scripts after WSL setup and user first bash run till the bad umask was discovered now have to be changed to sane defaults. This is exacerbated in git-based repos because git will track the change of perms to saner defaults as a (needless) change thereby status of git repo becomes dirty which simply put is both: confusing and annoying.

@0xMF don't worry, git only tracks +x, and the .bashrc changes are mentioned as a workaround

This also causes problems for zsh (compinit/compaudit). If you use a tool like antigen the directory permissions will throw shell errors when compinit/compaudit (command completion) is loaded.

Essentially any tool that performs basic checking for "other" write/read permissions will fail.

For anyone else trying to use dropbox, careful with symlinks to the windows /mnt/c/.... You'll likely run into a lot of problems. Unfortunately, dropbox for linux doesn't work yet either (because of the /proc/vmstat issue: #1071 ).

Hello, It's very strange. If I run ./configure, I found that the Makefile in the dir and sub dir only has permission rw no x. So some middle product didn't output, ./configure is right, but can't do make.

It's a big problem.

/usr/bin/m4: m4_esyscmd subprocess failed: Operation not permitted
/usr/bin/m4:configure.ac:489: cannot run command `./scripts/version.sh': Operation not permitted

I have put this in my ~/.profile in the meantime:

# Note: Bash on Windows does not currently apply umask properly.
if [ "$(umask)" = "0000" ]; then
>   umask 022
fi

@benhillis: if you have time to entertain my curiosity - is there a particular reason you don't run /bin/login?