Hi Grant,

On 04/10/13 17:40, Grant Likely wrote:
> The size of each hwid in a cpu nodes 'reg' property is defined by the
> parents #address-cells property in the normal way. The cpu parsing code
> has a bug where it will overrun the end of the property if
> address-cells is greater than one. This commit fixes the problem by
> adjusting the array size by the number of address cells. It also makes
> sure address-cells isn't zero for that would cause an infinite loop.
> 
> Signed-off-by: Grant Likely <[email protected]>
> Cc: Rob Herring <[email protected]>
> Cc: Benjamin Herrenschmidt <[email protected]>
> ---
> 
> I discovered this during code inspection. I don't think it is an actual
> bug seen in the wild, but the code does look wrong. I'd appreciate
> someone take a look and confirm that I've read the code right.
> 

Thanks for finding and fixing the bug.
I have tested this on ARM64 with 2 cell reg value using [1].

Tested-by: Sudeep KarkadaNagesha <[email protected]>

Regards,
Sudeep

[1] 
http://lists.infradead.org/pipermail/linux-arm-kernel/2013-October/206401.html

>  drivers/of/base.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index e4c9945..470b871 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -263,11 +263,11 @@ static bool __of_find_n_match_cpu_property(struct 
> device_node *cpun,
>       int ac, prop_len, tid;
>       u64 hwid;
>  
> -     ac = of_n_addr_cells(cpun);
> +     ac = of_n_addr_cells(cpun) ? : OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
>       cell = of_get_property(cpun, prop_name, &prop_len);
>       if (!cell)
>               return false;
> -     prop_len /= sizeof(*cell);
> +     prop_len /= sizeof(*cell) * ac;
>       for (tid = 0; tid < prop_len; tid++) {
>               hwid = of_read_number(cell, ac);
>               if (arch_match_cpu_phys_id(cpu, hwid)) {
> 


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

Reply via email to