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by westurner 122 days ago
Flatpak manifests include a list of ACLs per app. Flatseal is one way to change the permissions granted to a flatpak. Restarting an app is required for permissions changes to take effect.

Audit2allow and desbma/shh can generate policies. systrack, list-syscalls.rb, "B-Side: Binary-Level Static System Call Identification"; https://news.ycombinator.com/item?id=46726677

/? which linux lsm's allow online policy changes: https://www.google.com/search?q=which+linux+lsm%27s+allow+on...

Writing to securityfs requires root privs.

> for resource metering.

Also for optimization with objective costs.

> It's closer to metered execution than sandboxing,

Linux cgroups support resource quotas. Systemd supports specifying per-unit resource quotas.

/? what part of linux containers supports resource quotas? profiling? opcode counting? what part of linux containers supports resource quotas? profiling? opcode counting?

>> Opcode Counting: This is typically done through hardware counters and kernel instrumentation, specifically using perf_events and eBPF (specifically tracepoints or kprobes

Kernel docs > admin guide > perf_events: https://docs.kernel.org/admin-guide/perf-security.html :

> Usage of Performance Counters for Linux (perf_events) [1] , [2] , [3] can impose a considerable risk of leaking sensitive data accessed by monitored processes.

How to mitigate such concerns with lower-level opcode counting for eWASM?

Brendan Gegg's > perf examples: https://www.brendangregg.com/perf.html , and BPF/Perf book: https://www.brendangregg.com/bpf-performance-tools-book.html

I respectfully doubt that it's safe to trust runtime sandboxing. Containersec folks can probably explain why userspace filtering can never solve as well

bubblewrap README > Sandboxing: https://github.com/containers/bubblewrap#sandboxing

arch wiki > Bubblewrap > Using portals; XDG Desktop Portal: https://wiki.archlinux.org/title/Bubblewrap#Using_portals

> cloudflared/workerd: https://github.com/cloudflare/workerd :

>> WARNING: workerd is not a hardened sandbox

wasmtime-mte requires support for ARM64 Memory Tagging Extensions.