Impact
A fixed-output derivations on Linux can send file descriptors to files in the Nix store to another program running on the host (or another fixed-output derivation) via Unix domain sockets in the abstract namespace. This allows to modify the output of the derivation, after Nix has registered the path as "valid" and immutable in the Nix database. In particular, this allows the output of fixed-output derivations to be modified from their expected content.
Patches
See below.
Workarounds
Do not allow untrusted builds to occur on shared infrastructure.
References
https://hackmd.io/03UGerewRcy3db44JQoWvw
puckipedia Reporter
lf- Analyst
Impact
A fixed-output derivations on Linux can send file descriptors to files in the Nix store to another program running on the host (or another fixed-output derivation) via Unix domain sockets in the abstract namespace. This allows to modify the output of the derivation, after Nix has registered the path as "valid" and immutable in the Nix database. In particular, this allows the output of fixed-output derivations to be modified from their expected content.
Patches
See below.
Workarounds
Do not allow untrusted builds to occur on shared infrastructure.
References
https://hackmd.io/03UGerewRcy3db44JQoWvw