Messages in this thread | | | Subject | Frustrated with capabilities.. | From | Markku Savela <> | Date | Wed, 27 Aug 2008 12:31:10 +0300 |
| |
I just want to run an exectable with limited capabilities and assumed the following approach would work fine:
1) fork process 2) in child
2.1 set current capabilities (eip) using cap_set_proc 2.2 execve the executable.
But it frigging does not work! Just before the execve, the result of cap_to_text is
= cap_net_bind_service+eip
but, in the execve executable, the result is suddenly
= cap_net_bind_service+i
Why does the execve clear the effective and permitted capabities, against my clear instructions? (I also have the prctl KEEP_CAPS set, though in this case it should be irrelevant).
- The kernel is from ubuntu distro, 2.6.24.
- the executable *does* *not* have any setuid/setgid bits
- the upcoming file capabities will not be any help, because I will need to start the same executable with different capabilities depending on context.
If this is not a bug in kernel, it is a misdesign, which makes the obvious use of cap_set_proc rather useless...
-- Markku Savela
| |