syzbot


WARNING in comedi_compat_ioctl

Status: upstream: reported on 2025/07/17 12:50
Subsystems: comedi
[Documentation on labels]
Reported-by: syzbot+6048f8e5da91c7055339@syzkaller.appspotmail.com
First crash: 12d, last: 4d22h
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] Monthly comedi report (Jul 2025) 0 (1) 2025/07/24 09:32
[syzbot] [kernel?] WARNING in comedi_compat_ioctl 0 (1) 2025/07/17 12:50

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 8047 at mm/page_alloc.c:4935 __alloc_frozen_pages_noprof+0x30b/0x23f0 mm/page_alloc.c:4935
Modules linked in:
CPU: 0 UID: 0 PID: 8047 Comm: syz.3.460 Not tainted 6.16.0-rc6-syzkaller-00287-g990b11a523a8 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__alloc_frozen_pages_noprof+0x30b/0x23f0 mm/page_alloc.c:4935
Code: f0 5b 5d 41 5c 41 5d 41 5e 41 5f e9 7f d3 72 09 83 fe 0a 0f 86 0a fe ff ff 80 3d da eb 7e 0e 00 75 0b c6 05 d1 eb 7e 0e 01 90 <0f> 0b 90 45 31 f6 eb 81 4d 85 f6 74 22 44 89 fa 89 ee 4c 89 f7 e8
RSP: 0018:ffffc9000d08f988 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000015 RDI: 0000000000040dc0
RBP: 0000000140003d68 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000015
R13: 1ffff92001a11f46 R14: 0000000140003d68 R15: 0000000000000015
FS:  0000000000000000(0000) GS:ffff88809752d000(0063) knlGS:00000000f508eb40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f7407994 CR3: 000000006d8b0000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 __alloc_pages_noprof+0xb/0x1b0 mm/page_alloc.c:4993
 __alloc_pages_node_noprof include/linux/gfp.h:284 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:311 [inline]
 ___kmalloc_large_node+0x84/0x1e0 mm/slub.c:4272
 __kmalloc_large_node_noprof+0x1c/0x70 mm/slub.c:4300
 __do_kmalloc_node mm/slub.c:4316 [inline]
 __kmalloc_noprof.cold+0xc/0x61 mm/slub.c:4340
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kmalloc_array_noprof include/linux/slab.h:948 [inline]
 compat_insnlist drivers/comedi/comedi_fops.c:3145 [inline]
 comedi_compat_ioctl+0x3e9/0x910 drivers/comedi/comedi_fops.c:3225
 __do_compat_sys_ioctl fs/ioctl.c:1005 [inline]
 __se_compat_sys_ioctl fs/ioctl.c:948 [inline]
 __ia32_compat_sys_ioctl+0x23f/0x370 fs/ioctl.c:948
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x3a0 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf709e579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f508e55c EFLAGS: 00000296 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 000000008008640b
RDX: 0000000080113800 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	10 06                	adc    %al,(%rsi)
   2:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
   6:	10 07                	adc    %al,(%rdi)
   8:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
   c:	10 08                	adc    %cl,(%rax)
   e:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  1e:	00 51 52             	add    %dl,0x52(%rcx)
  21:	55                   	push   %rbp
  22:	89 e5                	mov    %esp,%ebp
  24:	0f 34                	sysenter
  26:	cd 80                	int    $0x80
* 28:	5d                   	pop    %rbp <-- trapping instruction
  29:	5a                   	pop    %rdx
  2a:	59                   	pop    %rcx
  2b:	c3                   	ret
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	90                   	nop
  2f:	90                   	nop
  30:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi
  37:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/21 02:26 upstream 990b11a523a8 7117feec .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in comedi_compat_ioctl
2025/07/18 20:54 upstream 6832a9317eee f550e092 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in comedi_compat_ioctl
2025/07/13 12:42 upstream 3f31a806a62e 3cda49cf .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in comedi_compat_ioctl
* Struck through repros no longer work on HEAD.