Re: [PATCHv2] of: Check for phys_addr_t overflows in early_init_dt_add_memory_arch

[Grant Likely]

On Thu, 19 Jun 2014 23:33:27 -0400 (EDT), Nicolas Pitre <nicolas.pitre@xxxxxxxxxx> wrote:
> On Thu, 19 Jun 2014, Laura Abbott wrote:
> 
> > The common early_init_dt_add_memory_arch takes the base and size
> > of a memory region as u64 types. The function never checks if
> > the base and size can actually fit in a phys_addr_t which may
> > be smaller than 64-bits. This may result in incorrect memory
> > being passed to memblock_add if the memory falls outside the
> > range of phys_addr_t. Add range checks for the base and size if
> > phys_addr_t is smaller than u64.
> > 
> > Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> > Tested-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> > Signed-off-by: Laura Abbott <lauraa@xxxxxxxxxxxxxx>
> 
> Acked-by: Nicolas Pitre <nico@xxxxxxxxxx>

Applied, thanks.

g.

> 
> > ---
> > v2: Switched to sizeof(phys_addr_t) < sizeof(u64) instead of macros.
> > Sending to right e-mails/mailing lists this time.
> > 
> >  drivers/of/fdt.c | 15 +++++++++++++++
> >  1 file changed, 15 insertions(+)
> > 
> > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> > index c4cddf0..b777d8f 100644
> > --- a/drivers/of/fdt.c
> > +++ b/drivers/of/fdt.c
> > @@ -880,6 +880,21 @@ void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
> >  	const u64 phys_offset = __pa(PAGE_OFFSET);
> >  	base &= PAGE_MASK;
> >  	size &= PAGE_MASK;
> > +
> > +	if (sizeof(phys_addr_t) < sizeof(u64)) {
> > +		if (base > ULONG_MAX) {
> > +			pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
> > +					base, base + size);
> > +			return;
> > +		}
> > +
> > +		if (base + size > ULONG_MAX) {
> > +			pr_warning("Ignoring memory range 0x%lx - 0x%llx\n",
> > +					ULONG_MAX, base + size);
> > +			size = ULONG_MAX - base;
> > +		}
> > +	}
> > +
> >  	if (base + size < phys_offset) {
> >  		pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
> >  			   base, base + size);
> > -- 
> > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> > hosted by The Linux Foundation
> > 

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/