Messages in this thread | | | Date | Fri, 6 Mar 2015 19:08:34 -0700 | Subject | Rcceiving a generic netlink multicast - should be restricted to the root user? | From | Craig Davison <> |
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I wrote a kernel module that sends generic Netlink multicasts, and wrote a userland client using libmnl that receives them.
That all works fine, but my client works even when it's not the root user.
man 7 netlink says:
Only processes with an effective UID of 0 or the CAP_NET_ADMIN capability may send or listen to a netlink multicast group.
The listen part of this is seemingly not true. I've tried this on kernels 3.13 (Ubuntu 14.04), 2.6.32 (CentOS 6) and 2.6.18 (CentOS 5).
Is this a bug?
If not: I know that restricting receiving generic netlink commands incoming to the kernel to being only from root is possible with GENL_ADMIN_PERM flag, but is it possible to send multicasts from the kernel that can only be received by root?
Thank you
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