Messages in this thread | | | Date | Wed, 31 Mar 2021 14:54:57 -0700 | From | Kees Cook <> | Subject | Re: [PATCH v8 3/6] stack: Optionally randomize kernel stack offset each syscall |
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On Wed, Mar 31, 2021 at 09:53:26AM +0200, Thomas Gleixner wrote: > On Tue, Mar 30 2021 at 13:57, Kees Cook wrote: > > +/* > > + * Do not use this anywhere else in the kernel. This is used here because > > + * it provides an arch-agnostic way to grow the stack with correct > > + * alignment. Also, since this use is being explicitly masked to a max of > > + * 10 bits, stack-clash style attacks are unlikely. For more details see > > + * "VLAs" in Documentation/process/deprecated.rst > > + * The asm statement is designed to convince the compiler to keep the > > + * allocation around even after "ptr" goes out of scope. > > Nit. That explanation of "ptr" might be better placed right at the > add_random...() macro.
Ah, yes! Fixed in v9.
> Other than that. > > Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Thank you for the reviews!
Do you want to take this via -tip (and leave off the arm64 patch until it is acked), or would you rather it go via arm64? (I've sent v9 now...)
-- Kees Cook
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