On 3/30/23 15:45, Damien Le Moal wrote:
> On 3/31/23 06:31, Chaitanya Kulkarni wrote:
>> Right now we don't check for valid module parameter value for
>> block size, that allows user to set negative values.
>>
>> Add a callback to error out when block size value is set < 1 before
>> module is loaded.
>>
>> Signed-off-by: Chaitanya Kulkarni <kch@xxxxxxxxxx>
>> ---
>> drivers/block/null_blk/main.c | 17 ++++++++++++++++-
>> 1 file changed, 16 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
>> index f55d88ebd7e6..d8d79c66a7aa 100644
>> --- a/drivers/block/null_blk/main.c
>> +++ b/drivers/block/null_blk/main.c
>> @@ -190,8 +190,23 @@ static int g_gb = 250;
>> device_param_cb(gb, &null_gb_param_ops, &g_gb, 0444);
>> MODULE_PARM_DESC(gb, "Size in GB");
>>
>> +static int null_set_bs(const char *s, const struct kernel_param *kp)
>> +{
>> + int ret;
>> +
>> + ret = null_param_store_int(s, kp->arg, 512, INT_MAX);
>> + if (ret)
>> + pr_err("valid range for bs value [512 ... %d]\n", INT_MAX);
> This is is only checking the range. block sizes must be power-of-2 as well but
> that is not checked. And for the range, block size up to INT_MAX ? That is not
> very reasonable.
>
>
I'll add ^2 check to next version.
any suggestions on what is a reasonable size we should limit to ?
-ck
