oss-sec mailing list archives
Disabling reading of kernel log buffer reading for user
From: halfdog <me () halfdog net>
Date: Fri, 13 Mar 2015 09:56:58 +0000
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello List, After years working on Linux, I just found out, that any user not only root can read the kernel log buffer - I never even considered that this could be the case. As this behavior is documented and expected, this is not a security vulnerability. But to avoid things like in [1], I would like to disable that on my machines. Questions: * What would be the side effects of making /dev/kmesg only root accessible? Maybe syslog not able to write kmessages to log? * Would it be safe to disable the syslog syscall for action SYSLOG_ACTION_READ_* and all users except root and syslog? Does someone have tested selinux config for that? hd [1] http://www.halfdog.net/Security/2015/HavingFunWithDmesg/ - -- http://www.halfdog.net/ PGP: 156A AE98 B91F 0114 FE88 2BD8 C459 9386 feed a bee -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlUCtGQACgkQxFmThv7tq+4FFQCeN4Txgu40/tDsWGSVaK2sm7La VusAnRUCtETL9IGmaeSyQUt2dyCQgCpV =Krnc -----END PGP SIGNATURE-----
Current thread:
- Disabling reading of kernel log buffer reading for user halfdog (Mar 13)
- Re: Disabling reading of kernel log buffer reading for user Marek Kroemeke (Mar 13)
- Re: Disabling reading of kernel log buffer reading for user Jann Horn (Mar 13)
- Re: Disabling reading of kernel log buffer reading for user Grandma Eubanks (Mar 13)