When null_blk queue mode is specified together with modprobe/insmod, a
check to prevent setting the nullb device queue mode to 1 (NULL_Q_RQ) is
done. However, the same check is not performed when setting up a nullb
device through configfs, resulting in a oops (NULL pointer dereference
for the device request queue).
Fix this problem by checking for an invalid queue mode value in
null_validate_conf(), propagating -EINVAL to null_add_dev() if the queue
mode is NULL_Q_RQ. While at it, also fix the propagation to user space
of null_add_dev() return value when a nullb device is created through
the power attribute of configfs.
Finally, remove the "1=rq" value from the list of possible values of
the queue_mode module argument to make it clear that this is no longer
a valid setting.
Fixes: e50b1e327aeb ("null_blk: remove legacy IO path")
Cc: [email protected]
Signed-off-by: Damien Le Moal <[email protected]>
---
Changes from v2:
* Fixed "Fixes" tag
Changes from v1:
* Removed reference to rq mode from queue_mode description
drivers/block/null_blk_main.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c
index 62c9654b9ce8..155dcef3b21a 100644
--- a/drivers/block/null_blk_main.c
+++ b/drivers/block/null_blk_main.c
@@ -130,7 +130,7 @@ static const struct kernel_param_ops
null_queue_mode_param_ops = {
};
device_param_cb(queue_mode, &null_queue_mode_param_ops, &g_queue_mode, 0444);
-MODULE_PARM_DESC(queue_mode, "Block interface to use
(0=bio,1=rq,2=multiqueue)");
+MODULE_PARM_DESC(queue_mode, "Block interface to use (0=bio,2=multiqueue)");
static int g_gb = 250;
module_param_named(gb, g_gb, int, 0444);
@@ -318,9 +318,10 @@ static ssize_t nullb_device_power_store(struct config_item
*item,
if (!dev->power && newp) {
if (test_and_set_bit(NULLB_DEV_FL_UP, &dev->flags))
return count;
- if (null_add_dev(dev)) {
+ ret = null_add_dev(dev);
+ if (ret) {
clear_bit(NULLB_DEV_FL_UP, &dev->flags);
- return -ENOMEM;
+ return ret;
}
set_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags);
@@ -1561,8 +1562,13 @@ static int null_init_tag_set(struct nullb *nullb, struct
blk_mq_tag_set *set)
return blk_mq_alloc_tag_set(set);
}
-static void null_validate_conf(struct nullb_device *dev)
+static int null_validate_conf(struct nullb_device *dev)
{
+ if (dev->queue_mode == NULL_Q_RQ) {
+ pr_err("null_blk: legacy IO path no longer available\n");
+ return -EINVAL;
+ }
+
dev->blocksize = round_down(dev->blocksize, 512);
dev->blocksize = clamp_t(unsigned int, dev->blocksize, 512, 4096);
@@ -1588,6 +1594,8 @@ static void null_validate_conf(struct nullb_device *dev)
/* can not stop a queue */
if (dev->queue_mode == NULL_Q_BIO)
dev->mbps = 0;
+
+ return 0;
}
#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
@@ -1620,7 +1628,9 @@ static int null_add_dev(struct nullb_device *dev)
struct nullb *nullb;
int rv;
- null_validate_conf(dev);
+ rv = null_validate_conf(dev);
+ if (rv)
+ goto out;
nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, dev->home_node);
if (!nullb) {
@@ -1648,8 +1658,10 @@ static int null_add_dev(struct nullb_device *dev)
if (rv)
goto out_cleanup_queues;
- if (!null_setup_fault())
+ if (!null_setup_fault()) {
+ rv = -EINVAL;
goto out_cleanup_queues;
+ }
nullb->tag_set->timeout = 5 * HZ;
nullb->q = blk_mq_init_queue(nullb->tag_set);
--
2.20.1
