Messages in this thread | | | Date | Thu, 31 Jan 2008 15:04:28 +0100 | From | devzero@web ... | Subject | Re: [PATCH] x86: introduce /dev/mem restrictions with a config option |
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nice !
did you think about some boot-time param , e.g. "insecure-devmem" or something like that?
recompiling kernel is time consuming.....
From: Arjan van de Ven <arjan@linux.intel.com> Subject: [PATCH] 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 <arjan@linux.intel.com> _______________________________________________________________________ Jetzt neu! Schützen Sie Ihren PC mit McAfee und WEB.DE. 30 Tage kostenlos testen. http://www.pc-sicherheit.web.de/startseite/?mc=022220
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