blk-mq: setup queue ->tag_set before initializing hctx

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: blk-mq: setup queue ->tag_set before initializing hctx Commit 7b815817aa58 ("blk-mq: add helper for checking if one CPU is mapped to specified hctx") needs to check queue mapping via tag set in hctx's cpuhp handler. However, q->tag_set may not be setup yet when the cpuhp handler is enabled, then kernel oops is triggered. Fix the issue by setup queue tag_set before initializing hctx.

References

• https://git.kernel.org/stable/c/73d964ce4bc8b4de88a7c2e40df494f0d5cd8950
• https://git.kernel.org/stable/c/25466e5b4bb11a8415ce8d0be89ab77135f7e444
• https://git.kernel.org/stable/c/d28b256db525d9432bc3eb2c8d83f7d3f5e1cc87
• https://git.kernel.org/stable/c/c25c0c9035bb8b28c844dfddeda7b8bdbcfcae95