== 2026-10-11T23:20:25Z E4a: pasta + tapexec + execve, interactive (no systemd unit) + pasta --config-net -q -f -a 192.168.100.2 -n 255.255.255.0 -g 192.168.100.1 --dns-forward 192.168.100.1 -- /bin/sh -c 'exec "$0" tap0 /bin/sh -c "$1"' /tmp/claude-1000/-home-johnandersen777-src-publicdomainrelay-kcp/90fa59d8-02f3-4261-b817-d037e7405f23/scratchpad/linux-proofs/bin/tapexec 'ip -br link show tap0; ip -br addr; exec /tmp/claude-1000/-home-johnandersen777-src-publicdomainrelay-kcp/90fa59d8-02f3-4261-b817-d037e7405f23/scratchpad/linux-proofs/bin/tapexec attach tap0' --- output: tapexec: pid=1 ppid=0 Uid: 0 0 0 0 | CapEff: 000001ffffffffff tapexec: uid_map="0 1000 1" tapexec: created persistent tap0, up; execve [/bin/sh -c ip -br link show tap0; ip -br addr; exec /tmp/claude-1000/-home-johnandersen777-src-publicdomainrelay-kcp/90fa59d8-02f3-4261-b817-d037e7405f23/scratchpad/linux-proofs/bin/tapexec attach tap0] tap0 DOWN 6a:04:14:c6:c6:63 lo UNKNOWN 127.0.0.1/8 ::1/128 enp8s0 UNKNOWN 192.168.100.2/24 fd7a:115c:a1e0::8539:8b59/128 fe80::b424:94ff:fea5:2d35/64 tap0 DOWN attach: pid=1 opened existing tap0 with IFF_TAP|IFF_NO_PI|IFF_VNET_HDR fd=4 (as firecracker does for host_dev_name) --- process tree (session of pasta 70962): PID PPID COMMAND COMMAND 70962 70960 pasta.avx2 pasta --config-net -q -f -a 192.168.100.2 -n 255.255.255.0 -g 192.168.100.1 --dns-forward 192.168.100.1 -- /bin/sh -c exec "$0" 70965 70962 \_ tapexec \_ /tmp/claude-1000/-home-johnandersen777-src-publicdomainrelay-kcp/90fa59d8-02f3-4261-b817-d037e7405f23/scratchpad/linux-proof pasta pid=70962 children=[70965] pid 70962 exe= comm=pasta.avx2 netns= userns= pid 70965 exe=/tmp/claude-1000/-home-johnandersen777-src-publicdomainrelay-kcp/90fa59d8-02f3-4261-b817-d037e7405f23/scratchpad/linux-proofs/bin/tapexec comm=tapexec netns=net:[4026533309] userns=user:[4026533150] grandchildren of 70965: [] host netns: net:[4026531833] --- tap seen from inside ns via nsenter --preserve-credentials -U -n -t 70965: tap0 UP 6a:04:14:c6:c6:63 tun type tap pi off vnet_hdr on persist on addrgenmode eui64 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535 tso_max_size 65536 tso_max_segs 65535 gro_max_size 65536 gso_ipv4_max_size 65536 gro_ipv4_max_size 65536 --- fds of exec'd process (tun fd from tapexec must not leak; attach fd present): 0 -> /dev/null 1 -> /tmp/claude-1000/-home-johnandersen777-src-publicdomainrelay-kcp/90fa59d8-02f3-4261-b817-d037e7405f23/scratchpad/linux-proofs/e4a.out 2 -> /tmp/claude-1000/-home-johnandersen777-src-publicdomainrelay-kcp/90fa59d8-02f3-4261-b817-d037e7405f23/scratchpad/linux-proofs/e4a.out 3 -> /sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/tmux-spawn-c6247bd3-38f6-459b-8a6c-5795c06f30c7.scope/cpu.max 4 -> /dev/net/tun 5 -> anon_inode:[eventpoll] 6 -> anon_inode:[eventfd] == 2026-10-11T23:20:26Z kill -TERM pasta 70962 pid 70962 gone pid 70965 STILL ALIVE cleanup: had to kill leftover attach == 2026-10-11T23:20:27Z E4a': kill -9 of pasta pasta=71020 child=71023 e4.sh: line 34: 71020 Killed setsid pasta --config-net -q -f -a 192.168.100.2 -n 255.255.255.0 -g 192.168.100.1 -- /bin/sh -c 'exec "$0" tap0 /bin/sh -c "$1"' $T "$INNER" > $P/e4a2.out 2>&1 pid 71020 gone pid 71023 STILL ALIVE (PPid: 1) cleanup: had to kill leftover attach == 2026-10-11T23:20:30Z E4a'': kill -9 of the exec'd child (VMM stand-in) -> pasta exits? pasta=71059 child=71062 pasta 71059 exited rc=137