Messages in this thread | | | Subject | Re: [PATCH] x86/pkeys: add check for pkey "overflow" | From | Dave Hansen <> | Date | Wed, 22 Jan 2020 11:09:47 -0800 |
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On 1/22/20 10:51 AM, Cyrill Gorcunov wrote: >> + /* >> + * This code should only be called with valid 'pkey' >> + * values originating from in-kernel users. Complain >> + * if a bad value is observed. >> + */ >> + WARN_ON_ONCE(pkey >= arch_max_pkey()); > Should not we rather abort this operation and exit with EINVAL > or something similar instead of calling wrmsr with overflowed > value? IOW, > > if (pkey >= arch_max_pkey()) { > WARN_ON_ONCE(1); > return -EINVAL; > }
I don't feel strongly about it. The reason I didn't do that is to minimize the chance that this would cause any functional regression.
It's not a huge chance, but I've certainly fat-fingered my share of off-by-one bugs.
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