LinuxDerivationBuilder: Use FD-based mounting API when available#15955
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xokdvium wants to merge 1 commit into
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LinuxDerivationBuilder: Use FD-based mounting API when available#15955xokdvium wants to merge 1 commit into
xokdvium wants to merge 1 commit into
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xokdvium
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Jun 1, 2026
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Amazing, musl still doesn't have open_tree/move_mount wrappers :( |
We now use open_tree/move_mount syscalls when available. glibc version support shouldn't be too much of a concern at this point - the wrappers have been added in glibc 2.36. There also was not a whole lot of validation of the sandbox paths, which is now fixed too (`.`, `..` filename are rejected, everything escaping the chroot is too).
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Also fixed the build with musl |
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If /nix/store is writeable at the source the bind mounts in the sandbox will be writeable too. Is it out of scope to control the read-only state of the sandbox mounts? |
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That's already the case, nothing has changed wrt to that. We have file level permissions to make stuff read-only, though I agree that it might be feasible to mount readonly, but I'm not sure how badly it would break things in practice. It might have ossified already enough that it would be a breaking change. I've done that previously for the new jail-based FreeBSD derivation builder. |
xokdvium
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Jun 2, 2026
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Probably needs a few more tests.
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Motivation
We now use open_tree/move_mount syscalls when available. glibc version support shouldn't be too much of a concern at this point - the wrappers have been added in glibc 2.36.
There also was not a whole lot of validation of the sandbox paths, which is now fixed too (
.,..filename are rejected, everything escaping the chroot is too).Context
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