syzbot


divide error in snd_pcm_lib_ioctl

Status: upstream: reported C repro on 2021/08/18 10:38
Reported-by: syzbot+830fc34d2fc44efb7ecb@syzkaller.appspotmail.com
First crash: 1029d, last: 999d
Fix bisection: failed (error log, bisect log)
  
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2021/10/17 11:26 16m bisect fix linux-4.19.y error job log (0)
2021/09/17 11:00 26m bisect fix linux-4.19.y job log (0) log

Sample crash report:
divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 8098 Comm: syz-executor317 Not tainted 4.19.204-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:snd_pcm_lib_ioctl_fifo_size sound/core/pcm_lib.c:1754 [inline]
RIP: 0010:snd_pcm_lib_ioctl+0x450/0x9a0 sound/core/pcm_lib.c:1779
Code: a0 17 fb 4c 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 00 05 00 00 49 8b 84 24 18 02 00 00 89 db 31 d2 <48> f7 f3 49 89 84 24 18 02 00 00 45 31 ed e9 de fb ff ff e8 88 a0
RSP: 0018:ffff888092bf7ba8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff864af1bf
RDX: 0000000000000000 RSI: ffffffff864af1c9 RDI: 0000000000000007
RBP: 000000000000000f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000007 R11: 0000000000000000 R12: ffff8880b32b0000
R13: ffff8880b32b0218 R14: 0000000000000000 R15: 0000000000000000
FS:  00000000016c6300(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020001090 CR3: 00000000b507e000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 fixup_unreferenced_params+0x5c5/0x8a0 sound/core/pcm_native.c:496
 snd_pcm_hw_refine_old_user sound/core/pcm_native.c:3600 [inline]
 snd_pcm_common_ioctl+0x144d/0x29a0 sound/core/pcm_native.c:2948
 snd_pcm_ioctl+0x7e/0xb0 sound/core/pcm_native.c:2985
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x443649
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffec06b0638 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004004a0 RCX: 0000000000443649
RDX: 00000000200010c0 RSI: 00000000c1004110 RDI: 0000000000000003
RBP: 00000000004031f0 R08: 0000000000000000 R09: 00000000004004a0
R10: 000000000000000f R11: 0000000000000246 R12: 0000000000403280
R13: 0000000000000000 R14: 00000000004b1018 R15: 00000000004004a0
Modules linked in:
---[ end trace 272791c8b61acd22 ]---
RIP: 0010:snd_pcm_lib_ioctl_fifo_size sound/core/pcm_lib.c:1754 [inline]
RIP: 0010:snd_pcm_lib_ioctl+0x450/0x9a0 sound/core/pcm_lib.c:1779
Code: a0 17 fb 4c 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 00 05 00 00 49 8b 84 24 18 02 00 00 89 db 31 d2 <48> f7 f3 49 89 84 24 18 02 00 00 45 31 ed e9 de fb ff ff e8 88 a0
RSP: 0018:ffff888092bf7ba8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff864af1bf
RDX: 0000000000000000 RSI: ffffffff864af1c9 RDI: 0000000000000007
RBP: 000000000000000f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000007 R11: 0000000000000000 R12: ffff8880b32b0000
R13: ffff8880b32b0218 R14: 0000000000000000 R15: 0000000000000000
FS:  00000000016c6300(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9c6003a008 CR3: 00000000b507e000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	fb                   	sti    
   1:	4c 89 ea             	mov    %r13,%rdx
   4:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
   b:	fc ff df 
   e:	48 c1 ea 03          	shr    $0x3,%rdx
  12:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
  16:	0f 85 00 05 00 00    	jne    0x51c
  1c:	49 8b 84 24 18 02 00 	mov    0x218(%r12),%rax
  23:	00 
  24:	89 db                	mov    %ebx,%ebx
  26:	31 d2                	xor    %edx,%edx
  28:	48 f7 f3             	div    %rbx <-- trapping instruction
  2b:	49 89 84 24 18 02 00 	mov    %rax,0x218(%r12)
  32:	00 
  33:	45 31 ed             	xor    %r13d,%r13d
  36:	e9 de fb ff ff       	jmpq   0xfffffc19
  3b:	e8                   	.byte 0xe8
  3c:	88                   	.byte 0x88
  3d:	a0                   	.byte 0xa0

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/08/18 10:37 linux-4.19.y 59456c9cc40c a2fe1cb5 .config console log report syz C ci2-linux-4-19 divide error in snd_pcm_lib_ioctl
* Struck through repros no longer work on HEAD.