Messages in this thread | | | From | Richard Weinberger <> | Date | Mon, 25 May 2020 09:54:49 +0200 | Subject | Re: Re: [PATCH v12 00/18] Enable FSGSBASE instructions |
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On Sun, May 24, 2020 at 11:20 PM Sasha Levin <sashal@kernel.org> wrote: > > On Sun, May 24, 2020 at 12:45:18PM -0700, hpa@zytor.com wrote: > >There are legitimate reasons to write a root-hole module, the main one being able to test security features like SMAP. I have requested before a TAINT flag specifically for this purpose, because TAINT_CRAP is nowhere near explicit enough, and is also used for staging drivers. Call it TAINT_TOXIC or TAINT_ROOTHOLE; it should always be accompanied with a CRIT level alert. > > What I don't like about our current system of TAINT_* flags is that > while we can improve it as much as we want, no one outside of the kernel > tree seems to be using it. While Thomas may have been commenting on > Graphene's behaviour, look at any other code that did the same thing:
Even if these modules would set TAINT_ROOTHOLE/TOXIC, the vast majority of users have no clue what these flags really mean nor bother to take them seriously.
Almost every customer system I get my hands on has the following flags set: C: Some driver from staging was "needed", mostly media or wifi stuff. O: Customer did a custom module. W: Random warning from vendor kernel at bootup because of a slightly configured device-tree, etc. P: Sadly too. Mostly because customer has custom module and forgot to set it GPL
All this trained users to believe that a few taint flags don't hurt and only in a perfect world none are set.
What works and raises attention is Steve's trace_printk() warning:
pr_warn("**********************************************************\n"); pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); pr_warn("** **\n"); pr_warn("** trace_printk() being used. Allocating extra memory. **\n"); pr_warn("** **\n"); pr_warn("** This means that this is a DEBUG kernel and it is **\n"); pr_warn("** unsafe for production use. **\n"); pr_warn("** **\n"); pr_warn("** If you see this message and you are not debugging **\n"); pr_warn("** the kernel, report this immediately to your vendor! **\n"); pr_warn("** **\n"); pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); pr_warn("**********************************************************\n");
Maybe we can add something like this for taints too? :-)
-- Thanks, //richard
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