From: André Almeida Date: Wed, 11 Sep 2019 14:46:36 +0000 (-0300) Subject: null_blk: validate the number of devices X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f7c4ce890dd23f2d41ad9630263aad6e9720af58;p=linux.git null_blk: validate the number of devices A negative number of devices is nonsensical, so change the type to unsigned. If the number of devices is 0, it is impossible for userspace to interact with the module, so refuse loading the driver for that case. Signed-off-by: André Almeida Signed-off-by: Jens Axboe --- diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c index bd6e5cd02a57b..53d4c15299844 100644 --- a/drivers/block/null_blk_main.c +++ b/drivers/block/null_blk_main.c @@ -141,7 +141,7 @@ static int g_bs = 512; module_param_named(bs, g_bs, int, 0444); MODULE_PARM_DESC(bs, "Block size (in bytes)"); -static int nr_devices = 1; +static unsigned int nr_devices = 1; module_param(nr_devices, int, 0444); MODULE_PARM_DESC(nr_devices, "Number of devices to register"); @@ -1767,6 +1767,10 @@ static int __init null_init(void) pr_err("null_blk: legacy IO path no longer available\n"); return -EINVAL; } + if (!nr_devices) { + pr_err("null_blk: invalid number of devices\n"); + return -EINVAL; + } if (g_queue_mode == NULL_Q_MQ && g_use_per_node_hctx) { if (g_submit_queues != nr_online_nodes) { pr_warn("null_blk: submit_queues param is set to %u.\n",