feat(seccomp): add seccomp-bpf filter support with TSYNC#93
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noeljackson wants to merge 1 commit intoedera-dev:mainfrom
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feat(seccomp): add seccomp-bpf filter support with TSYNC#93noeljackson wants to merge 1 commit intoedera-dev:mainfrom
noeljackson wants to merge 1 commit intoedera-dev:mainfrom
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Add optional seccomp-bpf filter installation to ExecutableSpec. The caller provides a filter program as BPF instruction tuples and styrolite installs it at the correct point in the execution sequence -- after PR_SET_NO_NEW_PRIVS and capability setup, but before execvpe(). Uses seccomp(2) with SECCOMP_FILTER_FLAG_TSYNC instead of prctl(PR_SET_SECCOMP) to synchronize the filter across all threads, preventing a race where a pre-existing thread could call a blocked syscall before the filter is applied. The seccomp field on ExecutableSpec is Optional and serde(default), so existing configs without seccomp continue to work unchanged.
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Summary
Add optional seccomp-bpf filter support to
ExecutableSpec, allowing callers toprovide a BPF filter program that styrolite installs at the correct point in the
container setup sequence.
Changes:
seccompmodule withSeccompFilterstruct (BPF instruction tuples + install method)ExecutableSpec.seccompfield (Option<SeccompFilter>,serde(default)for backward compat)execute()afterPR_SET_NO_NEW_PRIVSand beforeexecvpe()lib.rsWhy
seccomp(2)withSECCOMP_FILTER_FLAG_TSYNCinstead ofprctl(PR_SET_SECCOMP):prctl(PR_SET_SECCOMP)only applies the filter to the calling thread. If the processhas multiple threads (e.g. from a runtime or async executor), other threads can continue
making blocked syscalls until they individually install the filter.
seccomp(2)withSECCOMP_FILTER_FLAG_TSYNCatomically synchronizes the filter across all threads,closing this race window.
Backward compatible: Existing configs without a
seccompfield continue to workunchanged since the field defaults to
None.Test plan
cargo checkcompilesseccompfield deserialize correctly (serde default)