[syzbot] [virt?] [dri?] WARNING in virtio_gpu_alloc_vbufs

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fc02acf6ac0c Merge tag 'platform-drivers-x86-v7.2-4' of gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=171d103e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=145fa60d73086782
dashboard link: https://syzkaller.appspot.com/bug?extid=1b129b44597a126d2d79
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-fc02acf6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/eca05900a79c/vmlinux-fc02acf6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e655b72e0b5f/bzImage-fc02acf6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1b129b...@syzkaller.appspotmail.com

[drm] features: -virgl +edid -resource_blob -host_visible
[drm] features: -context_init -blob_alignment
------------[ cut here ]------------
kmem_cache of name 'virtio-gpu-vbufs' already exists
WARNING: mm/slab_common.c:111 at kmem_cache_sanity_check mm/slab_common.c:111 [inline], CPU#2: syz.4.468/7600
WARNING: mm/slab_common.c:111 at __kmem_cache_create_args+0xa6/0x420 mm/slab_common.c:352, CPU#2: syz.4.468/7600
Modules linked in:
CPU: 2 UID: 0 PID: 7600 Comm: syz.4.468 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:kmem_cache_sanity_check mm/slab_common.c:111 [inline]
RIP: 0010:__kmem_cache_create_args+0xa9/0x420 mm/slab_common.c:352
Code: 48 8b 43 60 48 8d 58 a0 48 3d 30 82 d8 8e 74 1f 48 8b 7b 58 48 89 ee e8 a5 a3 5d 09 85 c0 75 e0 48 8d 3d fa 2d ce 0e 48 89 ee <67> 48 0f b9 3a be 20 00 00 00 48 89 ef e8 25 a5 5d 09 48 85 c0 0f
RSP: 0018:ffffc9000c80ef58 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888026364500 RCX: fffff52001901dc6
RDX: 0000000000000000 RSI: ffffffff8c6f7ae0 RDI: ffffffff912750c0
RBP: ffffffff8c6f7ae0 R08: 0000000000000000 R09: fffffbfff2244f3a
R10: ffffc9000c80ef58 R11: 0000000000000000 R12: 0000000000000000
R13: ffffc9000c80efc8 R14: 00000000000000d8 R15: 0000000000000000
FS: 00007f71682e66c0(0000) GS:ffff8880d5fdc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8a775556c8 CR3: 000000005c66a000 CR4: 0000000000352ef0
Call Trace:
<TASK>
__kmem_cache_create include/linux/slab.h:399 [inline]
virtio_gpu_alloc_vbufs+0xc2/0x150 drivers/gpu/drm/virtio/virtgpu_vq.c:75
virtio_gpu_init.cold+0x51c/0x126e drivers/gpu/drm/virtio/virtgpu_kms.c:228
virtio_gpu_probe+0x21c/0x360 drivers/gpu/drm/virtio/virtgpu_drv.c:103
virtio_dev_probe+0x6a2/0xbe0 drivers/virtio/virtio.c:347
call_driver_probe drivers/base/dd.c:628 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:706
__driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
__device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
bus_probe_device+0x64/0x160 drivers/base/bus.c:620
device_add+0x121d/0x1970 drivers/base/core.c:3772
register_virtio_device+0x4f0/0x5d0 drivers/virtio/virtio.c:568
virtio_pci_probe+0x255/0x410 drivers/virtio/virtio_pci_common.c:722
local_pci_probe+0xdd/0x1b0 drivers/pci/pci-driver.c:332
pci_call_probe+0x176/0x800 drivers/pci/pci-driver.c:394
__pci_device_probe drivers/pci/pci-driver.c:455 [inline]
pci_device_probe+0x1cd/0x370 drivers/pci/pci-driver.c:489
call_driver_probe drivers/base/dd.c:628 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:706
__driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
__device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
pci_bus_add_device+0xc5/0x100 drivers/pci/bus.c:373
pci_bus_add_devices+0x9a/0x1f0 drivers/pci/bus.c:394
pci_rescan_bus+0x2a/0x40 drivers/pci/probe.c:3500
rescan_store+0xfb/0x130 drivers/pci/pci-sysfs.c:473
bus_attr_store+0x74/0xb0 drivers/base/bus.c:172
sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6ac/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f716739df99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f71682e6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f7167626090 RCX: 00007f716739df99
RDX: 0000000000000001 RSI: 00002000000001c0 RDI: 0000000000000006
RBP: 00007f7167434ec4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7167626128 R14: 00007f7167626090 R15: 00007ffd459912c8
</TASK>
----------------
Code disassembly (best guess):
0: 48 8b 43 60 mov 0x60(%rbx),%rax
4: 48 8d 58 a0 lea -0x60(%rax),%rbx
8: 48 3d 30 82 d8 8e cmp $0xffffffff8ed88230,%rax
e: 74 1f je 0x2f
10: 48 8b 7b 58 mov 0x58(%rbx),%rdi
14: 48 89 ee mov %rbp,%rsi
17: e8 a5 a3 5d 09 call 0x95da3c1
1c: 85 c0 test %eax,%eax
1e: 75 e0 jne 0x0
20: 48 8d 3d fa 2d ce 0e lea 0xece2dfa(%rip),%rdi # 0xece2e21
27: 48 89 ee mov %rbp,%rsi
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: be 20 00 00 00 mov $0x20,%esi
34: 48 89 ef mov %rbp,%rdi
37: e8 25 a5 5d 09 call 0x95da561
3c: 48 85 c0 test %rax,%rax
3f: 0f .byte 0xf


---
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 syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup