This is a note to let you know that I've just added the patch titled null_blk: fix ida error handling in null_add_dev() to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: null_blk-fix-ida-error-handling-in-null_add_dev.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit ee622dea8fd80a82ec75ce0b0eded0b4a09f288f Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Date: Fri Jul 15 11:12:14 2022 +0300 null_blk: fix ida error handling in null_add_dev() [ Upstream commit ee452a8d984f94fa8e894f003a52e776e4572881 ] There needs to be some error checking if ida_simple_get() fails. Also call ida_free() if there are errors later. Fixes: 94bc02e30fb8 ("nullb: use ida to manage index") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Link: https://lore.kernel.org/r/YtEhXsr6vJeoiYhd@kili Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c index 13eae973eaea..6cbdd8a691d2 100644 --- a/drivers/block/null_blk_main.c +++ b/drivers/block/null_blk_main.c @@ -1711,8 +1711,13 @@ static int null_add_dev(struct nullb_device *dev) blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, nullb->q); mutex_lock(&lock); - nullb->index = ida_simple_get(&nullb_indexes, 0, 0, GFP_KERNEL); - dev->index = nullb->index; + rv = ida_simple_get(&nullb_indexes, 0, 0, GFP_KERNEL); + if (rv < 0) { + mutex_unlock(&lock); + goto out_cleanup_zone; + } + nullb->index = rv; + dev->index = rv; mutex_unlock(&lock); blk_queue_logical_block_size(nullb->q, dev->blocksize); @@ -1724,13 +1729,16 @@ static int null_add_dev(struct nullb_device *dev) rv = null_gendisk_register(nullb); if (rv) - goto out_cleanup_zone; + goto out_ida_free; mutex_lock(&lock); list_add_tail(&nullb->list, &nullb_list); mutex_unlock(&lock); return 0; + +out_ida_free: + ida_free(&nullb_indexes, nullb->index); out_cleanup_zone: if (dev->zoned) null_zone_exit(dev);