fix: allow sendmsg(2) and recvmsg(2) syscalls in our Linux sandbox #7779
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bolinfest
changed the title
wpt-oai
approved these changes
Dec 9, 2025
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This changes our default Landlock policy to allow
sendmsg(2)andrecvmsg(2)syscalls. We believe these were originally denied out of an abundance of caution, but given thatsend(2)norrecv(2)are allowed today [which provide comparable capability to the*msgequivalents], we do not believe allowing them grants any privileges beyond what we already allow.Rather than using the syscall as the security boundary, preventing access to the potentially hazardous file descriptor in the first place seems like the right layer of defense.
In particular, this makes it possible for
shell-tool-mcpto run on Linux when using a read-only sandbox for the Bash process, as demonstrated byaccept_elicitation_for_prompt_rule()now succeeding in CI.