Hello, syzbot found the following issue on: HEAD commit: 10d4879f9ef0 Merge tag 'thermal-6.0-rc3' of git://git.kern.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=116400e5080000 kernel config: https://syzkaller.appspot.com/x/.config?x=312be25752c7fe30 dashboard link: https://syzkaller.appspot.com/bug?extid=30e9df1b3f1d5117d77f compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=126b8675080000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+30e9df1b3f1d5117d77f@xxxxxxxxxxxxxxxxxxxxxxxxx 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: 12 Comm: kworker/u16:1 Not tainted 6.0.0-rc2-syzkaller-00283-g10d4879f9ef0 #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:1905 Code: 08 e8 7a 39 e0 fc 48 8b 1d 63 54 ae 0c 48 b8 00 00 00 00 00 fc ff df 0f b6 2d b2 3e ae 0c 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:ffffc900005ffc98 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff849b0096 RDI: ffffffff849b2f00 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff849b2f00 R13: 0000000000000001 R14: ffff888012459400 R15: ffff888011875800 FS: 0000000000000000(0000) GS:ffff88802c900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0afb5ff718 CR3: 000000001b6a0000 CR4: 0000000000150ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> floppy_ready+0x83/0x1940 drivers/block/floppy.c:1932 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:start_motor+0x3a/0x3f0 drivers/block/floppy.c:1905 Code: 08 e8 7a 39 e0 fc 48 8b 1d 63 54 ae 0c 48 b8 00 00 00 00 00 fc ff df 0f b6 2d b2 3e ae 0c 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:ffffc900005ffc98 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff849b0096 RDI: ffffffff849b2f00 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff849b2f00 R13: 0000000000000001 R14: ffff888012459400 R15: ffff888011875800 FS: 0000000000000000(0000) GS:ffff88802c900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0afb5ff718 CR3: 00000000284ad000 CR4: 0000000000150ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 08 e8 or %ch,%al 2: 7a 39 jp 0x3d 4: e0 fc loopne 0x2 6: 48 8b 1d 63 54 ae 0c mov 0xcae5463(%rip),%rbx # 0xcae5470 d: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 14: fc ff df 17: 0f b6 2d b2 3e ae 0c movzbl 0xcae3eb2(%rip),%ebp # 0xcae3ed0 1e: 48 89 da mov %rbx,%rdx 21: 48 c1 ea 03 shr $0x3,%rdx 25: 89 e9 mov %ebp,%ecx 27: 41 89 ed mov %ebp,%r13d * 2a: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction 2e: 83 e1 03 and $0x3,%ecx 31: 41 83 e5 03 and $0x3,%r13d 35: 84 c0 test %al,%al 37: 74 08 je 0x41 39: 3c 03 cmp $0x3,%al 3b: 0f .byte 0xf 3c: 8e .byte 0x8e 3d: be .byte 0xbe 3e: 02 00 add (%rax),%al --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
