From: Arjan van de Ven Date: Thu, 24 Apr 2008 21:40:47 +0000 (+0200) Subject: x86: introduce /dev/mem restrictions with a config option X-Git-Tag: v2.6.26-rc1~1058^2~7 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ae531c26c5c2a28ca1b35a75b39b3b256850f2c8;p=pandora-kernel.git x86: introduce /dev/mem restrictions with a config option This patch introduces a restriction on /dev/mem: Only non-memory can be read or written unless the newly introduced config option is set. The X server needs access to /dev/mem for the PCI space, but it doesn't need access to memory; both the file permissions and SELinux permissions of /dev/mem just make X effectively super-super powerful. With the exception of the BIOS area, there's just no valid app that uses /dev/mem on actual memory. Other popular users of /dev/mem are rootkits and the like. (note: mmap access of memory via /dev/mem was already not allowed since a really long time) People who want to use /dev/mem for kernel debugging can enable the config option. The restrictions of this patch have been in the Fedora and RHEL kernels for at least 4 years without any problems. Signed-off-by: Arjan van de Ven Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- Reading git-diff-tree failed