fix(cli): harden permission stdio check #21778
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bartlomieju
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Jan 3, 2024
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| "❌ Permission prompt length (100017 bytes) was larger than the configured maximum length (10240 bytes): denying request.\r\n", | ||
| "❌ WARNING: This may indicate that code is trying to bypass or hide permission check requests.\r\n", | ||
| "❌ Run again with --allow-read to bypass this check if this is really what you want to do.\r\n", |
bartlomieju
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Jan 4, 2024
Harden the code that does permission checks to protect against re-opening of stdin. Code that runs FFI is vulnerable to an attack where fd 0 is closed during a permission check and re-opened with a file that contains a positive response (ie: `y` or `A`). While FFI code is dangerous in general, we can make it more difficult for FFI-enabled code to bypass additional permission checks. - Checks to see if the underlying file for stdin has changed from the start to the end of the permission check (detects races) - Checks to see if the message is excessively long (lowering the window for races) - Checks to see if stdin and stderr are still terminals at the end of the function (making races more difficult)
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Harden the code that does permission checks to protect against re-opening of stdin.
Code that runs FFI is vulnerable to an attack where fd 0 is closed during a permission check and re-opened with a file that contains a positive response (ie:
yorA). While FFI code is dangerous in general, we can make it more difficult for FFI-enabled code to bypass additional permission checks.