syzbot


WARNING in comedi_unlocked_ioctl

Status: upstream: reported C repro on 2025/07/11 04:26
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+032ab98511c4a6864a8f@syzkaller.appspotmail.com
First crash: 7d06h, last: 5d12h
Bug presence (1)
Date Name Commit Repro Result
2025/07/12 upstream (ToT) 379f604cc3dc C [report] WARNING in comedi_unlocked_ioctl
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in comedi_unlocked_ioctl kernel -1 C 219 now 14d 2/29 upstream: reported C repro on 2025/07/04 08:17
linux-5.15 WARNING in comedi_unlocked_ioctl origin:upstream -1 C 6 12h08m 7d22h 0/3 upstream: reported C repro on 2025/07/10 11:52
linux-6.1 WARNING in comedi_unlocked_ioctl origin:upstream -1 C 8 4d16h 7d05h 0/3 upstream: reported C repro on 2025/07/11 04:55

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5943 at mm/page_alloc.c:4433 __alloc_pages+0x2de/0x460 mm/page_alloc.c:4433
Modules linked in:
CPU: 1 PID: 5943 Comm: syz.0.16 Not tainted 6.6.97-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__alloc_pages+0x2de/0x460 mm/page_alloc.c:4433
Code: 0c 25 28 00 00 00 48 3b 8c 24 a0 00 00 00 0f 85 a0 00 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 c6 05 c0 cb 62 0c 01 <0f> 0b eb a5 a9 00 00 08 00 8b 74 24 0c 75 3e 44 89 f1 81 e1 7f ff
RSP: 0018:ffffc900033879c0 EFLAGS: 00010246
RAX: ffffc90003387a00 RBX: 1ffff92000670f3c RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc90003387a28
RBP: ffffc90003387ac0 R08: ffffc90003387a27 R09: 0000000000000000
R10: ffffc90003387a00 R11: fffff52000670f45 R12: 000000000000001a
R13: 0000000000000000 R14: 0000000000040dc0 R15: dffffc0000000000
FS:  0000555569a8c500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000001859c0 CR3: 0000000076de6000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 __alloc_pages_node include/linux/gfp.h:237 [inline]
 alloc_pages_node include/linux/gfp.h:260 [inline]
 __kmalloc_large_node+0x8c/0x1e0 mm/slab_common.c:1148
 __do_kmalloc_node mm/slab_common.c:995 [inline]
 __kmalloc+0x111/0x240 mm/slab_common.c:1020
 kmalloc_array include/linux/slab.h:637 [inline]
 kcalloc include/linux/slab.h:668 [inline]
 comedi_unlocked_ioctl+0x9f0/0xf00 drivers/comedi/comedi_fops.c:2242
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fcc69d8e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc0d25d278 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fcc69fb5fa0 RCX: 00007fcc69d8e929
RDX: 00002000001859c0 RSI: 000000008010640b RDI: 0000000000000003
RBP: 00007fcc69e10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcc69fb5fa0 R14: 00007fcc69fb5fa0 R15: 0000000000000003
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/11 11:06 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in comedi_unlocked_ioctl
2025/07/12 22:05 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in comedi_unlocked_ioctl
2025/07/12 22:05 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in comedi_unlocked_ioctl
2025/07/11 04:25 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in comedi_unlocked_ioctl
* Struck through repros no longer work on HEAD.