From: =?UTF-8?q?Andr=C3=A9=20Almeida?= <andrealmeid@collabora.com>
Date: Wed, 11 Sep 2019 11:46:36 -0300
Subject: [PATCH] null_blk: validate the number of devices
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Git-commit: f7c4ce890dd23f2d41ad9630263aad6e9720af58
Patch-Mainline: v5.4-rc1
References: bsc#1175995,jsc#SLE-15608
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 <andrealmeid@collabora.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
drivers/block/null_blk_main.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c
index bd6e5cd02a57..53d4c1529984 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",
--
2.16.4