floppy0: no floppy controllers found general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 PID: 10 Comm: kworker/u4:0 Not tainted 6.2.0-rc8-next-20230214-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 Workqueue: events_unbound async_run_entry_fn RIP: 0010:blkg_destroy_all+0xa6/0x260 block/blk-cgroup.c:529 Code: 08 e8 7e 87 14 06 48 8b 44 24 10 80 38 00 0f 85 a5 01 00 00 48 8b 04 24 48 8b 98 80 05 00 00 48 8d 6b f8 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 0f 85 77 01 00 00 48 8b 03 49 39 dd 4c 8d 78 f8 0f RSP: 0000:ffffc900000f7ad0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81667f94 RDX: 1ffff11003c4e019 RSI: 0000000000000004 RDI: ffffc900000f7a60 RBP: fffffffffffffff8 R08: 0000000000000001 R09: 0000000000000003 R10: fffff5200001ef4c R11: 0000000000000001 R12: dffffc0000000000 R13: ffff88801e124580 R14: ffff88801e124090 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000000c571000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: blkcg_exit_disk+0x15/0x50 block/blk-cgroup.c:1352 disk_release+0xe3/0x490 block/genhd.c:1167 device_release+0xa3/0x240 drivers/base/core.c:2436 kobject_cleanup lib/kobject.c:681 [inline] kobject_release lib/kobject.c:712 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1c2/0x4d0 lib/kobject.c:729 put_device+0x1f/0x30 drivers/base/core.c:3701 put_disk+0x45/0x60 block/genhd.c:1453 do_floppy_init drivers/block/floppy.c:4758 [inline] floppy_async_init+0x39e/0x2cc0 drivers/block/floppy.c:4767 async_run_entry_fn+0x9c/0x530 kernel/async.c:127 process_one_work+0x9bf/0x1820 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:blkg_destroy_all+0xa6/0x260 block/blk-cgroup.c:529 Code: 08 e8 7e 87 14 06 48 8b 44 24 10 80 38 00 0f 85 a5 01 00 00 48 8b 04 24 48 8b 98 80 05 00 00 48 8d 6b f8 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 0f 85 77 01 00 00 48 8b 03 49 39 dd 4c 8d 78 f8 0f RSP: 0000:ffffc900000f7ad0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81667f94 RDX: 1ffff11003c4e019 RSI: 0000000000000004 RDI: ffffc900000f7a60 RBP: fffffffffffffff8 R08: 0000000000000001 R09: 0000000000000003 R10: fffff5200001ef4c R11: 0000000000000001 R12: dffffc0000000000 R13: ffff88801e124580 R14: ffff88801e124090 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000000c571000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 08 e8 or %ch,%al 2: 7e 87 jle 0xffffff8b 4: 14 06 adc $0x6,%al 6: 48 8b 44 24 10 mov 0x10(%rsp),%rax b: 80 38 00 cmpb $0x0,(%rax) e: 0f 85 a5 01 00 00 jne 0x1b9 14: 48 8b 04 24 mov (%rsp),%rax 18: 48 8b 98 80 05 00 00 mov 0x580(%rax),%rbx 1f: 48 8d 6b f8 lea -0x8(%rbx),%rbp 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction 2f: 0f 85 77 01 00 00 jne 0x1ac 35: 48 8b 03 mov (%rbx),%rax 38: 49 39 dd cmp %rbx,%r13 3b: 4c 8d 78 f8 lea -0x8(%rax),%r15 3f: 0f .byte 0xf