block: Fix handling of offline queues in blk_mq_alloc_request_hctx()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: block: Fix handling of offline queues in blk_mq_alloc_request_hctx() This patch prevents that test nvme/004 triggers the following: UBSAN: array-index-out-of-bounds in block/blk-mq.h:135:9 index 512 is out of range for type 'long unsigned int [512]' Call Trace: show_stack+0x52/0x58 dump_stack_lvl+0x49/0x5e dump_stack+0x10/0x12 ubsan_epilogue+0x9/0x3b __ubsan_handle_out_of_bounds.cold+0x44/0x49 blk_mq_alloc_request_hctx+0x304/0x310 __nvme_submit_sync_cmd+0x70/0x200 [nvme_core] nvmf_connect_io_queue+0x23e/0x2a0 [nvme_fabrics] nvme_loop_connect_io_queues+0x8d/0xb0 [nvme_loop] nvme_loop_create_ctrl+0x58e/0x7d0 [nvme_loop] nvmf_create_ctrl+0x1d7/0x4d0 [nvme_fabrics] nvmf_dev_write+0xae/0x111 [nvme_fabrics] vfs_write+0x144/0x560 ksys_write+0xb7/0x140 __x64_sys_write+0x42/0x50 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae

References

• https://git.kernel.org/stable/c/7fa28a7c3d74933a4fc22d341b60927952f31c19
• https://git.kernel.org/stable/c/b5e65ef044d627effdc2599040b6d204e003f955
• https://git.kernel.org/stable/c/b202a0bd2580ee5b0453772c46d464152fafff73
• https://git.kernel.org/stable/c/14dc7a18abbe4176f5626c13c333670da8e06aa1