On 2023/4/8 02:41, Bart Van Assche wrote: > On 4/6/23 07:50, Chengming Zhou wrote: >> These are some cleanup patches of blk-cgroup. Thanks for review. > > With these patches applied, my kernel test VM crashes during boot. The following crash disappears if I revert these patches: Thanks for the report. I will try to reproduce it first and look into this today. > > BUG: KASAN: null-ptr-deref in bio_associate_blkg_from_css+0x83/0x240 > Read of size 8 at addr 0000000000000518 by task blkid/5885 > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-debian-1.16.0-5 04/01/2014 > Call Trace: > dump_stack_lvl+0x4a/0x80 > print_report+0x21e/0x260 > kasan_report+0xc2/0xf0 > __asan_load8+0x69/0x90 > bio_associate_blkg_from_css+0x83/0x240 > bfq_bio_bfqg+0xce/0x120 [bfq] > bfq_bic_update_cgroup+0x2f/0x3c0 [bfq] > bfq_init_rq+0x1e8/0xb10 [bfq] > bfq_insert_request.isra.0+0xa3/0x420 [bfq] > bfq_insert_requests+0xca/0xf0 [bfq] > blk_mq_dispatch_rq_list+0x4c0/0xb00 > __blk_mq_sched_dispatch_requests+0x15e/0x200 > blk_mq_sched_dispatch_requests+0x8b/0xc0 > __blk_mq_run_hw_queue+0x3ff/0x500 > __blk_mq_delay_run_hw_queue+0x23a/0x300 > blk_mq_run_hw_queue+0x14e/0x350 > blk_mq_sched_insert_request+0x181/0x1f0 > blk_execute_rq+0xf4/0x300 > scsi_execute_cmd+0x23e/0x350 > sr_do_ioctl+0x173/0x3d0 [sr_mod] > sr_packet+0x60/0x90 [sr_mod] > cdrom_get_track_info.constprop.0+0x125/0x170 [cdrom] > cdrom_get_last_written+0x1d4/0x2d0 [cdrom] > mmc_ioctl_cdrom_last_written+0x85/0x120 [cdrom] > mmc_ioctl+0x10b/0x1d0 [cdrom] > cdrom_ioctl+0xa66/0x1270 [cdrom] > sr_block_ioctl+0xee/0x130 [sr_mod] > blkdev_ioctl+0x1bb/0x3f0 > __x64_sys_ioctl+0xc7/0xe0 > do_syscall_64+0x34/0x80 > entry_SYSCALL_64_after_hwframe+0x46/0xb0 > > Bart.
