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| author |  sommerfeld <sommerfeld@sommerfeld.dev> | 2026-05-29 11:18:13 +0100 |
|---|---|---|
| committer | sommerfeld <sommerfeld@sommerfeld.dev> | 2026-05-29 11:18:13 +0100 |
| commit | 1ab5e40fc75e293b87f645fc2de08e0a0fe3d50f (patch) | |
| tree | b3e5c39fcbcf2a95e1df5b3cf05ac1f150ca6b3a /etc | |
| parent | 88e152d3fe8174f1a2ba338714ceba1cb73ffa40 (diff) | |
| download | dotfiles-1ab5e40fc75e293b87f645fc2de08e0a0fe3d50f.tar.gz dotfiles-1ab5e40fc75e293b87f645fc2de08e0a0fe3d50f.tar.bz2 dotfiles-1ab5e40fc75e293b87f645fc2de08e0a0fe3d50f.zip | |
fix(hardened): restore podman compatibility on linux-hardened
Two breakages observed on first linux-hardened boot:
1. `podman run` failed because linux-hardened sets
kernel.unprivileged_userns_clone=0 by default (stock linux: 1).
Rootless podman requires unprivileged user namespaces. Restoring
the stock-kernel default via sysctl — this is a documented hardened
knob meant to be flipped back if you actually use rootless
containers. No-op on stock kernel.
2. "kernel does not support overlay fs: 'overlay' is not supported over
btrfs". Kernel overlayfs cannot use a btrfs subvolume as lowerdir;
podman needs fuse-overlayfs as the user-mode shim. ~10-30% slower
I/O than native overlay but works correctly and is the upstream
recommendation for btrfs-backed rootless storage.
Diffstat (limited to 'etc')
| -rw-r--r-- | etc/sysctl.d/99-sysctl.conf | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/etc/sysctl.d/99-sysctl.conf b/etc/sysctl.d/99-sysctl.conf index 3a43da9..d20197e 100644 --- a/etc/sysctl.d/99-sysctl.conf +++ b/etc/sysctl.d/99-sysctl.conf @@ -3,12 +3,16 @@ # kernel.dmesg_restrict=0 — read dmesg as user during driver/kernel debug. # kernel.perf_event_paranoid=-1 — `perf record` on own user-space binaries # without sudo. Kernel-space tracepoints still need root. +# kernel.unprivileged_userns_clone=1 — required by rootless podman. +# linux-hardened defaults this to 0; stock linux defaults it to 1. +# Restoring the stock default here. No-op on stock kernel. # kernel.yama.ptrace_scope is left at the kernel default (1, parent-only), # which keeps `gdb ./a.out`, `lldb -- ./bin`, `rust-gdb target/...` working; # attach-by-PID (`gdb -p`) requires sudo. kernel.sysrq = 1 kernel.dmesg_restrict = 0 kernel.perf_event_paranoid = -1 +kernel.unprivileged_userns_clone = 1 net.core.netdev_max_backlog = 16384 net.core.somaxconn = 8192 net.ipv4.tcp_fastopen = 3 |