command_status=-1 floppy1: floppy timeout called no cont in shutdown! floppy1: floppy_shutdown: timeout handler died. floppy1: FDC access conflict! 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: 59 Comm: kworker/u16:3 Not tainted 6.6.0-rc2-syzkaller-gd90b0276af8f #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Workqueue: floppy floppy_work_workfn RIP: 0010:start_motor+0x3a/0x3e0 drivers/block/floppy.c:1905 Code: 08 e8 aa 1e 4a fc 48 8b 1d e3 e6 1a 0d 48 b8 00 00 00 00 00 fc ff df 0f b6 2d 32 d1 1a 0d 48 89 da 48 c1 ea 03 89 e9 41 89 ed <0f> b6 04 02 83 e1 03 41 83 e5 03 84 c0 74 08 3c 03 0f 8e a8 02 00 RSP: 0018:ffffc90000cd7c70 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff853ca656 RDI: ffffffff853cdbb0 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff853cdbb0 R13: 0000000000000001 R14: ffffc90000cd7d80 R15: ffff888012c7d000 FS: 0000000000000000(0000) GS:ffff88806b700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc9d2798000 CR3: 000000000c976000 CR4: 0000000000350ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: floppy_ready+0x87/0x1b40 drivers/block/floppy.c:1932 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:start_motor+0x3a/0x3e0 drivers/block/floppy.c:1905 Code: 08 e8 aa 1e 4a fc 48 8b 1d e3 e6 1a 0d 48 b8 00 00 00 00 00 fc ff df 0f b6 2d 32 d1 1a 0d 48 89 da 48 c1 ea 03 89 e9 41 89 ed <0f> b6 04 02 83 e1 03 41 83 e5 03 84 c0 74 08 3c 03 0f 8e a8 02 00 RSP: 0018:ffffc90000cd7c70 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff853ca656 RDI: ffffffff853cdbb0 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff853cdbb0 R13: 0000000000000001 R14: ffffc90000cd7d80 R15: ffff888012c7d000 FS: 0000000000000000(0000) GS:ffff88806b600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc9d3319c98 CR3: 000000003c9ae000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: e8 aa 1e 4a fc call 0xfc4a1eaf 5: 48 8b 1d e3 e6 1a 0d mov 0xd1ae6e3(%rip),%rbx # 0xd1ae6ef c: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 13: fc ff df 16: 0f b6 2d 32 d1 1a 0d movzbl 0xd1ad132(%rip),%ebp # 0xd1ad14f 1d: 48 89 da mov %rbx,%rdx 20: 48 c1 ea 03 shr $0x3,%rdx 24: 89 e9 mov %ebp,%ecx 26: 41 89 ed mov %ebp,%r13d * 29: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction 2d: 83 e1 03 and $0x3,%ecx 30: 41 83 e5 03 and $0x3,%r13d 34: 84 c0 test %al,%al 36: 74 08 je 0x40 38: 3c 03 cmp $0x3,%al 3a: 0f .byte 0xf 3b: 8e .byte 0x8e 3c: a8 02 test $0x2,%al