CVE-2023-54227

In the Linux kernel, the following vulnerability has been resolved:

blk-mq: fix tags leak when shrink nrhwqueues

Although we don't need to realloc set->tags[] when shrink nrhwqueues, we need to free them. Or these tags will be leaked.

How to reproduce: 1. mount -t configfs configfs /mnt 2. modprobe nullblk nrdevices=0 submitqueues=8 3. mkdir /mnt/nullb/nullb0 4. echo 1 > /mnt/nullb/nullb0/power 5. echo 4 > /mnt/nullb/nullb0/submitqueues 6. rmdir /mnt/nullb/nullb0

In step 4, will alloc 9 tags (8 submit queues and 1 poll queue), then in step 5, newnrhw_queues = 5 (4 submit queues and 1 poll queue). At last in step 6, only these 5 tags are freed, the other 4 tags leaked.