6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Damien Le Moal <dlemoal@xxxxxxxxxx>
commit d9ff882b54f99f96787fa3df7cd938966843c418 upstream.
When powering on a null_blk device that is not already on, the return
value ret that is initialized to be count is reused to check the return
value of null_add_dev(), leading to nullb_device_power_store() to return
null_add_dev() return value (0 on success) instead of "count".
So make sure to set ret to be equal to count when there are no errors.
Fixes: a2db328b0839 ("null_blk: fix null-ptr-dereference while configuring 'power' and 'submit_queues'")
Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
Reviewed-by: Yu Kuai <yukuai3@xxxxxxxxxx>
Reviewed-by: Kanchan Joshi <joshi.k@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240527043445.235267-1-dlemoal@xxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/block/null_blk/main.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -470,6 +470,7 @@ static ssize_t nullb_device_power_store(
set_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags);
dev->power = newp;
+ ret = count;
} else if (dev->power && !newp) {
if (test_and_clear_bit(NULLB_DEV_FL_UP, &dev->flags)) {
dev->power = newp;
