fs.copyFile fails if source is readonly and target is a WSL volume

[juanrgm]

Version

v18.7.0

Platform

Linux 774484ed2c79 5.10.102.1-microsoft-standard-WSL2 #1 SMP Wed Mar 2 00:30:59 UTC 2022 x86_64 Linux

Subsystem

fs

What steps will reproduce the bug?

• Command Prompt

docker run --rm -it ^
-e "CODE=require('fs').copyFileSync('/tmp/file', '/target/file')" ^
-v "%TEMP%:/target" ^
node:alpine ^
sh -c "touch /tmp/file && chmod -w /tmp/file && node -e 'eval(process.env.CODE)'"

• Git Bash

docker run --rm -it \
-e "CODE=require('fs').copyFileSync('/tmp/file', '/target/file')" \
-v "$TEMP:/target" \
node:alpine \
sh -c "touch /tmp/file && chmod -w /tmp/file && node -e 'eval(process.env.CODE)'"

How often does it reproduce? Is there a required condition?

Always.

What is the expected behavior?

No error.

What do you see instead?

node:internal/fs/utils:348
    throw err;
    ^

Error: EACCES: permission denied, copyfile '/tmp/file' -> '/target/file'
    at Object.copyFileSync (node:fs:2866:3)
    at eval (eval at <anonymous> ([eval]:1:1), <anonymous>:1:15)
    at [eval]:1:1
    at Script.runInThisContext (node:vm:129:12)
    at Object.runInThisContext (node:vm:313:38)
    at node:internal/process/execution:76:19
    at [eval]-wrapper:6:22
    at evalScript (node:internal/process/execution:75:60)
    at node:internal/main/eval_string:27:3 {
  errno: -13,
  syscall: 'copyfile',
  code: 'EACCES',
  path: '/tmp/file',
  dest: '/target/file'
}

Additional information

• fs.copyFile fails with permission denied when source is read-only #37284

[prettydiff]

Is the file in question read protected by the operating system? If the operating system has marked a file as read protected, such that it is locked by an underlying operating system process Node will not be able to perform the necessary fs.open method on the file to access the file contents. You will not see this very often on files you, as a user or administrator, own. However, it will happen on some files at the file system root, in system32, file associated with regedit, and so forth. You should still be able to see these files with fs.readdir and fs.stat though.

See also:

• https://support.microsoft.com/en-us/topic/description-of-the-windows-file-protection-feature-db28f515-6512-63d1-6178-982ed2022ffb#:~:text=Windows%20File%20Protection%20(WFP)%20prevents,programs%20and%20the%20operating%20system.
• https://thegeekpage.com/unblock-a-file-blocked-by-windows-10/

[juanrgm]

But this it works:

• Command Prompt

docker run --rm -it ^
-v "%TEMP%:/target" ^
node:alpine ^
sh -c "touch /tmp/file && chmod -w /tmp/file && cp /tmp/file /target/file"