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: 3757 Comm: kworker/u16:4 Not tainted 5.15.0-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Workqueue: floppy floppy_work_workfn RIP: 0010:start_motor+0x3a/0x3f0 drivers/block/floppy.c:1906 Code: 08 e8 da 3c 05 fd 48 8b 1d 03 14 e6 0b 48 b8 00 00 00 00 00 fc ff df 0f b6 2d 12 fe e5 0b 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 be 02 00 RSP: 0018:ffffc900029a7ca0 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff84728996 RDI: ffffffff8472c6e0 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8472c74a R11: 0000000000000000 R12: ffffffff8472c6e0 R13: 0000000000000001 R14: ffff88801bd62900 R15: ffff888010c71800 FS: 0000000000000000(0000) GS:ffff88802cb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002c125000 CR3: 000000001fd5b000 CR4: 0000000000150ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: floppy_ready+0x83/0x1850 drivers/block/floppy.c:1933 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Modules linked in: ---[ end trace 73c8486563ff86af ]--- RIP: 0010:start_motor+0x3a/0x3f0 drivers/block/floppy.c:1906 Code: 08 e8 da 3c 05 fd 48 8b 1d 03 14 e6 0b 48 b8 00 00 00 00 00 fc ff df 0f b6 2d 12 fe e5 0b 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 be 02 00 RSP: 0018:ffffc900029a7ca0 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff84728996 RDI: ffffffff8472c6e0 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8472c74a R11: 0000000000000000 R12: ffffffff8472c6e0 R13: 0000000000000001 R14: ffff88801bd62900 R15: ffff888010c71800 FS: 0000000000000000(0000) GS:ffff88802cb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002c125000 CR3: 000000001fd5b000 CR4: 0000000000150ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: e8 da 3c 05 fd callq 0xfd053cdf 5: 48 8b 1d 03 14 e6 0b mov 0xbe61403(%rip),%rbx # 0xbe6140f c: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 13: fc ff df 16: 0f b6 2d 12 fe e5 0b movzbl 0xbe5fe12(%rip),%ebp # 0xbe5fe2f 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: be .byte 0xbe 3d: 02 00 add (%rax),%al