[kaltsit-10]

Motivation

launch_cache_manager / launch_cache_messager assemble a shell command by interpolating configuration-derived values (model path, cache protocol/dtype, splitwise role, the speculative-config JSON, ...) and run it via subprocess.Popen(..., shell=True).

If any interpolated value contains shell metacharacters (space, ;, &&, quotes), the command is re-parsed by the shell:

• an argument is corrupted (e.g. a model path containing a space breaks the launch),
• a single quote inside the --speculative_config / --default_dtype values breaks the manually added quoting,
• a crafted value (...; cmd) is executed as a separate shell command (CWE-78, command injection).

Modifications

fastdeploy/cache_manager/prefix_cache_manager.py

• Quote every string-valued argument interpolated into the two launch commands with shlex.quote(), including the executable path (sys.executable, py_path).
• Remove the manual single quotes around --speculative_config / --default_dtype; shlex.quote() escapes them correctly even when the JSON contains quotes.
• Numeric arguments (int(...) conversions), the environment-variable prefixes and the trailing log redirection are unchanged.
• The change is behavior-preserving for values without metacharacters - shlex.quote() returns such values unchanged - so this is a minimal hardening rather than a refactor of the command assembly (env prefixes and the > redirection are intentionally untouched).

tests/cache_manager/test_prefix_cache_manager.py

• Add two unit tests that capture the launch command and assert, via shlex.split(), that values carrying shell metacharacters (model dir; touch ..., zmq && ...) arrive as single, unmodified argv elements for both the cache-manager and cache-messager launch paths.

Usage or Command

No new usage. To run the new tests:

python -m pytest tests/cache_manager/test_prefix_cache_manager.py -k quotes_source_values -v

Accuracy Tests

Not applicable - this change does not touch model computation, kernels or outputs.

Checklist

• Add at least a tag in the PR title. ([BugFix])
• Format your code, run pre-commit before commit.
• Add unit tests. Please write the reason in this PR if no unit tests.
• Provide accuracy results. (N/A - see above)
• If the current PR is submitting to the release branch, make sure the PR has been submitted to the develop branch, then cherry-pick it to the release branch with the [Cherry-Pick] PR tag. (N/A - this PR targets develop)

[CLAassistant]

All committers have signed the CLA.