[qhwudbebd]

Whenever I think about writing a central privileged daemon to grant capabilities to other processes, I'm puzzled by the choice to remove the old version of CAP_SETPCAP in 2.6.24: "grant or remove new capabilities to/from an existing running process" - sadly it still exists but means something else in newer kernels with filesystem capabilities.

(In a sense, not having this capability in processes running as root is theatre anyway: you have /dev/kmem access so could just edit the kernel data structures. It's just doing so cleanly that is no longer possible.)

Being able to briefly escalate my editor to have the capabilities to write /etc/wibble.conf when I started editing it as a non-privileged user, then take away the capability again would be more convenient that always needing to run the editor as root. (So convenient, in fact, that people fake this with little editor helpers that do the equivalent of 'really tee FILE-TO-WRITE >/dev/null', but that's an ugly hack.)

[Denvercoder9]

> you have /dev/kmem access so could just edit the kernel data structures.

Not anymore: since kernel 2.6.26 /dev/kmem only exists if CONFIG_DEVKMEM is enabled, and it was removed completely in 5.13.

[1] https://lwn.net/Articles/851531/ [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin...