kernel/erl_boot_server: harden binary_to_term against unknown atoms#11233
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maennchen wants to merge 1 commit into
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kernel/erl_boot_server: harden binary_to_term against unknown atoms#11233maennchen wants to merge 1 commit into
maennchen wants to merge 1 commit into
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handle_command/3 decoded raw TCP data from whitelisted clients with
binary_to_term/1. Even though boot clients are fully trusted, decoding
untrusted-shaped payloads with the default options is unnecessary: any
atoms embedded in a payload are permanently interned before pattern
matching, so a malformed message could grow the atom table.
As a precaution, switch to binary_to_term(Msg, [safe]), which raises
badarg instead of interning unknown atoms or creating new funs. The
existing catch wraps this as {'EXIT', badarg}, now replied to the client
as {error, bad_command}.
This is a defence-in-depth hardening change, not a security fix; the
module already assumes a complete trust relationship with its clients.
Contributor
CT Test Results 2 files 74 suites 1h 11m 5s ⏱️ For more details on these failures, see this check. Results for commit bad018c. ♻️ This comment has been updated with latest results. To speed up review, make sure that you have read Contributing to Erlang/OTP and that all checks pass. See the TESTING and DEVELOPMENT HowTo guides for details about how to run test locally. Artifacts
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handle_command/3decoded raw TCP data from whitelisted clients withbinary_to_term/1. Even though boot clients are fully trusted, decoding untrusted-shaped payloads with the default options is unnecessary: any atoms embedded in a payload are permanently interned before pattern matching, so a malformed message could grow the atom table.As a precaution, this switches to
binary_to_term(Msg, [safe]), which raisesbadarginstead of interning unknown atoms or creating new funs. The existingcatchwraps this as{'EXIT', badarg}, now replied to the client as{error, bad_command}.This is a defence-in-depth hardening change, not a security fix; the module already assumes a complete trust relationship with its clients.