Messages in this thread | | | Date | Wed, 8 Nov 2006 20:14:00 -0800 | From | Chris Wright <> | Subject | Re: RFC PATCH: apply security_syslog() only to the syslog() syscall, not to /proc/kmsg |
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* Sergey Vlasov (vsu@altlinux.ru) wrote: > Then what would you think about another solution: > > 1) When sys_syslog() is called with commands 2 (read) or 9 (get unread > count), additionally call security_syslog(1) to check that the > process has permissions to open the kernel log. This change by > itself will not make any difference, because all existing > implementations of the security_ops->syslog hook treat the operation > codes 1, 2 and 9 the same way. > > 2) Change cap_syslog() and dummy_syslog() to permit commands 2 and 9 > for unprivileged users, in addition to 3 and 10 which are currently > permitted. This will not really permit access through sys_syslog() > due to the added security_syslog(1) check, but if a process somehow > got access to an open file descriptor for /proc/kmsg, it would be > able to read from it. Also, because selinux_syslog() is not > changed, under SELinux the process will still need to have > additional privileges even if it has /proc/kmsg open.
It's a bit clumsy in the extra caveats for sys_syslog and cap_syslog, but does achieve what you're after. We lose default checking on the actual read access, but perhaps this is a fair tradeoff. Stephen, James do you have any issues with this for SELinux?
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