"No removable drive detected." when /tmp is mounted as noexec

[szotsaki]

• Etcher version: 1.1.2
• Operating system and architecture: openSUSE Leap 42.3, x64

Mount /tmp as noexec (many people and some distros do that by default) and click on "Select drive" after you chose an image. It will show "No removable drive detected".

Console log:

Uncaught Error: spawn EACCES
    at exports._errnoException (util.js:1022:11)
    at ChildProcess.spawn (internal/child_process.js:313:11)
    at exports.spawn (child_process.js:399:9)
    at Object.exports.execFile (child_process.js:160:15)
    at Object.module.(anonymous function) [as execFile] (ELECTRON_ASAR.js:200:20)
    at executeScript (/tmp/.mount_npruyq/usr/bin/resources/app.asar/node_modules/drivelist/lib/execute.js:87:16)
    at createTemporaryScriptFile (/tmp/.mount_npruyq/usr/bin/resources/app.asar/node_modules/drivelist/lib/execute.js:153:5)
    at fs.writeFile (/tmp/.mount_npruyq/usr/bin/resources/app.asar/node_modules/drivelist/lib/execute.js:67:5)
    at FSReqWrap.oncomplete (fs.js:112:15)

[lurch]

Yeah, that'll be because we write the drivelist script to /tmp before executing it. See https://github.com/resin-io-modules/drivelist/blob/master/scripts/linux.sh

We've already moved the drivelist functionality into native code for Windows (because it solved a lot of spawning problems) but we've not yet done that for Linux or macOS.

[jviotti]

@lurch What do you think about spawning the drives somewhere else in the mean-time, like $HOME/.etcher/tmp/ or something like that?

[lurch]

I dunno, that might work. What does @szotsaki think?

I did a bit of googling, and found a bunch of pages telling you how to enable a noexec /tmp directory, and also a bunch of pages telling you how to temporarily disable the noexec option ;-) https://debian-administration.org/article/57/Making_/tmp_non-executable

I did a little bit of digging, and drivelist uses https://nodejs.org/api/os.html#os_os_tmpdir to determine where to write its files, and it seems that function respects the TMPDIR variable:

$ node
> os.tmpdir()
'/tmp'
$ TMPDIR=/foo node
> os.tmpdir()
'/foo'
$ node
> os.tmpdir()
'/tmp'

So @szotsaki could you try running TMPDIR=some/executable/path etcher-electron (or maybe TMPDIR=some/executable/path etcher-1.1.2-linux-x86_64.AppImage) and let us know if that fixes your problem?

[szotsaki]

Yes, I used the remount option to make /tmp executable but only root can do that, so I think it's not a good solution. Modifying it in a program and knowing that that program can accidentally crash leaving /tmp in exec state may have awful consequences.

Directory selection idea: I recommend to adhere to Freedesktop specification, specifically $XDG_RUNTIME_DIR or maybe $XDG_CACHE_HOME.

Running ethcher with TMPDIR=$XDG_RUNTIME_DIR ./etcher-1.1.2-x86_64.AppImage made it work with noexec, thank you for the tip.

[lurch]

Modifying it in a program

Sorry, that's not what I was suggesting. I was just illustrating that other programs can have problems with a non-executable /tmp directory too ;-)

Thanks for the info about $XDG_RUNTIME_DIR !

[jviotti]

@szotsaki Thanks a lot for the XDG suggestions. I'll be sending a PR very soon :)

[jviotti]

See balena-io-modules/drivelist#209

[lurch]

Re-opening this issue, as the proposed fix actually breaks things for other Linux distros, see balena-io-modules/drivelist#209 (comment)

(BTW it seems $XDG_CACHE_HOME isn't set on Ubuntu 14.04)

[lurch]

Closing, as drivelist in Etcher has been upgraded.