syzbot


general protection fault in start_motor
Status: upstream: reported on 2021/10/21 14:07
Reported-by: syzbot+4e9b2677f1f8fba5cb18@syzkaller.appspotmail.com
First crash: 222d, last: 75d

Sample crash report:
floppy1: disk change line=0
floppy1: flags=20
setup_rw_floppy:rw_command dtime=17
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: 9 Comm: kworker/u16:0 Not tainted 5.17.0-rc7-syzkaller-00235-gaad611a868d1 #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 2a fc fb fc 48 8b 1d d3 43 04 0c 48 b8 00 00 00 00 00 fc ff df 0f b6 2d e2 2d 04 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:ffffc900005cfca8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff847bf966 RDI: ffffffff847c0d60
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff847c0dca R11: 0000000000000000 R12: ffffffff847c0d60
R13: 0000000000000001 R14: ffff888011850700 R15: ffff888010c75800
FS:  0000000000000000(0000) GS:ffff88802cb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c00027d0a0 CR3: 000000004f98c000 CR4: 0000000000150ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 floppy_ready+0x83/0x1850 drivers/block/floppy.c:1933
 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307
 worker_thread+0x657/0x1110 kernel/workqueue.c:2454
 kthread+0x2e9/0x3a0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:start_motor+0x3a/0x3f0 drivers/block/floppy.c:1906
Code: 08 e8 2a fc fb fc 48 8b 1d d3 43 04 0c 48 b8 00 00 00 00 00 fc ff df 0f b6 2d e2 2d 04 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:ffffc900005cfca8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff847bf966 RDI: ffffffff847c0d60
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff847c0dca R11: 0000000000000000 R12: ffffffff847c0d60
R13: 0000000000000001 R14: ffff888011850700 R15: ffff888010c75800
FS:  0000000000000000(0000) GS:ffff88802ca00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8f6e145300 CR3: 000000000b88e000 CR4: 0000000000150ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	08 e8                	or     %ch,%al
   2:	2a fc                	sub    %ah,%bh
   4:	fb                   	sti
   5:	fc                   	cld
   6:	48 8b 1d d3 43 04 0c 	mov    0xc0443d3(%rip),%rbx        # 0xc0443e0
   d:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  14:	fc ff df
  17:	0f b6 2d e2 2d 04 0c 	movzbl 0xc042de2(%rip),%ebp        # 0xc042e00
  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

Crashes (10):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-qemu-upstream 2022/03/13 06:33 upstream aad611a868d1 9e8eaa75 .config log report info general protection fault in start_motor
ci-qemu-upstream 2022/01/15 12:29 upstream 112450df61b7 723cfaf0 .config log report info general protection fault in start_motor
ci-qemu-upstream 2021/11/16 14:47 upstream 8ab774587903 600426bd .config log report info general protection fault in start_motor
ci-qemu-upstream 2021/11/15 14:58 upstream 8ab774587903 83f5c9b5 .config log report info general protection fault in start_motor
ci-qemu-upstream 2021/11/01 02:26 upstream 8bb7eca972ad 098b5d53 .config log report info general protection fault in start_motor
ci-qemu-upstream-386 2022/01/14 23:25 upstream 871bfa02d08d 53e00b45 .config log report info general protection fault in start_motor
ci-qemu-upstream-386 2021/12/04 22:39 upstream bbef3c7a63d2 a617004c .config log report info general protection fault in start_motor
ci-qemu-upstream-386 2021/11/12 11:05 upstream 5833291ab6de 75b04091 .config log report info general protection fault in start_motor
ci-qemu-upstream-386 2021/10/17 13:44 upstream d999ade1cc86 0c5d9412 .config log report info general protection fault in start_motor
ci-qemu-upstream-386 2021/11/21 00:54 upstream a90af8f15bdc 4eb20a4e .config log report info KASAN: use-after-free Read in start_motor