[syzbot] [virtualization?] upstream boot error: WARNING: refcount bug in __free_pages_ok

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: b3603fcb79b1 Merge tag 'dlm-6.9' of git://git.kernel.org/p..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10f04c81180000
kernel config: https://syzkaller.appspot.com/x/.config?x=fcb5bfbee0a42b54
dashboard link: https://syzkaller.appspot.com/bug?extid=70f57d8a3ae84934c003
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/43969dffd4a6/disk-b3603fcb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ef48ab3b378b/vmlinux-b3603fcb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/728f5ff2b6fe/bzImage-b3603fcb.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+70f57d...@syzkaller.appspotmail.com

Key type pkcs7_test registered
Block layer SCSI generic (bsg) driver version 0.4 loaded (major 239)
io scheduler mq-deadline registered
io scheduler kyber registered
io scheduler bfq registered
input: Power Button as /devices/LNXSYSTM:00/LNXPWRBN:00/input/input0
ACPI: button: Power Button [PWRF]
input: Sleep Button as /devices/LNXSYSTM:00/LNXSLPBN:00/input/input1
ACPI: button: Sleep Button [SLPF]
ioatdma: Intel(R) QuickData Technology Driver 5.00
ACPI: \_SB_.LNKC: Enabled at IRQ 11
virtio-pci 0000:00:03.0: virtio_pci: leaving for legacy driver
ACPI: \_SB_.LNKD: Enabled at IRQ 10
virtio-pci 0000:00:04.0: virtio_pci: leaving for legacy driver
ACPI: \_SB_.LNKB: Enabled at IRQ 10
virtio-pci 0000:00:06.0: virtio_pci: leaving for legacy driver
virtio-pci 0000:00:07.0: virtio_pci: leaving for legacy driver
N_HDLC line discipline registered with maxframe=4096
Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
00:03: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
00:04: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a 16550A
00:05: ttyS2 at I/O 0x3e8 (irq = 6, base_baud = 115200) is a 16550A
00:06: ttyS3 at I/O 0x2e8 (irq = 7, base_baud = 115200) is a 16550A
Non-volatile memory driver v1.3
Linux agpgart interface v0.103
ACPI: bus type drm_connector registered
[drm] Initialized vgem 1.0.0 20120112 for vgem on minor 0
[drm] Initialized vkms 1.0.0 20180514 for vkms on minor 1
Console: switching to colour frame buffer device 128x48
platform vkms: [drm] fb0: vkmsdrmfb frame buffer device
usbcore: registered new interface driver udl
brd: module loaded
loop: module loaded
zram: Added device: zram0
null_blk: disk nullb0 created
null_blk: module loaded
Guest personality initialized and is inactive
VMCI host device registered (name=vmci, major=10, minor=118)
Initialized host personality
usbcore: registered new interface driver rtsx_usb
usbcore: registered new interface driver viperboard
usbcore: registered new interface driver dln2
usbcore: registered new interface driver pn533_usb
nfcsim 0.2 initialized
usbcore: registered new interface driver port100
usbcore: registered new interface driver nfcmrvl
Loading iSCSI transport class v2.0-870.
virtio_scsi virtio0: 1/0/0 default/read/poll queues
------------[ cut here ]------------
refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 0 PID: 1 at lib/refcount.c:31 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:31
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.8.0-syzkaller-11567-gb3603fcb79b1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
RIP: 0010:refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:31
Code: b2 00 00 00 e8 57 d4 f2 fc 5b 5d c3 cc cc cc cc e8 4b d4 f2 fc c6 05 0c f9 ef 0a 01 90 48 c7 c7 a0 5d 1e 8c e8 b7 75 b5 fc 90 <0f> 0b 90 90 eb d9 e8 2b d4 f2 fc c6 05 e9 f8 ef 0a 01 90 48 c7 c7
RSP: 0000:ffffc90000066e18 EFLAGS: 00010246
RAX: 76f86e452fcad900 RBX: ffff8880210d2aec RCX: ffff888016ac8000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000004 R08: ffffffff8157ffe2 R09: fffffbfff1c396e0
R10: dffffc0000000000 R11: fffffbfff1c396e0 R12: ffffea000502cdc0
R13: ffffea000502cdc8 R14: 1ffffd4000a059b9 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88823ffff000 CR3: 000000000e132000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1141 [inline]
__free_pages_ok+0xc54/0xd80 mm/page_alloc.c:1270
make_alloc_exact+0xa3/0xf0 mm/page_alloc.c:4829
vring_alloc_queue drivers/virtio/virtio_ring.c:319 [inline]
vring_alloc_queue_split+0x20a/0x600 drivers/virtio/virtio_ring.c:1108
vring_create_virtqueue_split+0xc6/0x310 drivers/virtio/virtio_ring.c:1158
vring_create_virtqueue+0xca/0x110 drivers/virtio/virtio_ring.c:2683
setup_vq+0xe9/0x2d0 drivers/virtio/virtio_pci_legacy.c:131
vp_setup_vq+0xbf/0x330 drivers/virtio/virtio_pci_common.c:189
vp_find_vqs_msix+0x8b2/0xc80 drivers/virtio/virtio_pci_common.c:331
vp_find_vqs+0x4c/0x4e0 drivers/virtio/virtio_pci_common.c:408
virtio_find_vqs include/linux/virtio_config.h:233 [inline]
virtscsi_init+0x8db/0xd00 drivers/scsi/virtio_scsi.c:887
virtscsi_probe+0x3ea/0xf60 drivers/scsi/virtio_scsi.c:945
virtio_dev_probe+0x991/0xaf0 drivers/virtio/virtio.c:311
really_probe+0x29e/0xc50 drivers/base/dd.c:658
__driver_probe_device+0x1a2/0x3e0 drivers/base/dd.c:800
driver_probe_device+0x50/0x430 drivers/base/dd.c:830
__driver_attach+0x45f/0x710 drivers/base/dd.c:1216
bus_for_each_dev+0x239/0x2b0 drivers/base/bus.c:368
bus_add_driver+0x347/0x620 drivers/base/bus.c:673
driver_register+0x23a/0x320 drivers/base/driver.c:246
virtio_scsi_init+0x65/0xe0 drivers/scsi/virtio_scsi.c:1083
do_one_initcall+0x248/0x880 init/main.c:1238
do_initcall_level+0x157/0x210 init/main.c:1300
do_initcalls+0x3f/0x80 init/main.c:1316
kernel_init_freeable+0x435/0x5d0 init/main.c:1548
kernel_init+0x1d/0x2b0 init/main.c:1437
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
</TASK>


---
This report is generated by a bot. It may contain errors.
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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:
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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

[Michael S. Tsirkin]

I think I saw this already and also with virtio scsi. virtio
core does not seem to be doing anything special here,
Cc virtio scsi maintainers.

[Stefan Hajnoczi]

The oldest commit that syzkaller found is a memory management pull
request:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?id=e5eb28f6d1afebed4bb7d740a797d0390bd3a357

I can't reproduce the issue locally with QEMU 8.2.0 so I don't have a
way to bisect.

I reviewed the virtio_scsi.c git log and there have been few changes
over the last several months. I couldn't spot an issue in this patch,
but the most likely virtio-scsi commit is:

commit 95e7249691f082a5178d4d6f60fcdee91da458ab
Author: Mike Christie <michael....@oracle.com>
Date: Wed Dec 13 23:26:49 2023 -0600

scsi: virtio_scsi: Add mq_poll support

Stefan

[Michael S. Tsirkin]

Send a revert and ask syzbot to test it then?

[Stefan Hajnoczi]

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 52998cdd8d3438df9a77c858a827b8932da1bb28

This is the last time virtio_scsi.c was touched. If the test passes then
the issue is probably in another subsystem and we can bisect more recent
commits. If it fails, then older virtio_scsi.c commits need to be
bisected.

Stefan

[Mike Christie]

I also tested the current kernel and didn't hit it.

In this mail:

https://lore.kernel.org/all/ZfKPf_pG...@localhost.localdomain/

from this thread:

https://lore.kernel.org/all/37cb2e7c-97f1-4179...@I-love.SAKURA.ne.jp/T/

it looks like Oscar is saying he has a fix right?

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+70f57d...@syzkaller.appspotmail.com

Tested on:

commit: 52998cdd Merge branch '6.8/scsi-staging' into 6.8/scsi..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel config: https://syzkaller.appspot.com/x/.config?x=7b1f286a7e950707

dashboard link: https://syzkaller.appspot.com/bug?extid=70f57d8a3ae84934c003
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Note: no patches were applied.
Note: testing is done by a robot and is best-effort only.

[Stefan Hajnoczi]

Yes, here is Oscar's work-in-progress fix:
https://lore.kernel.org/all/20240319183212.1...@suse.de/

Commit 217b2119b9e2 ("mm,page_owner: implement the tracking of the
stacks count") introduced the issue and it was merged via commit
902861e34c40 ("Merge tag 'mm-stable-2024-03-13-20-04' of
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm").

To be 100% sure, I'll test the commit in question and its parent:

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 4bedfb314bdd85c1662ecc46fa25b33b998f994d

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 217b2119b9e260609958db413876f211038f00ee

Stefan

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+70f57d...@syzkaller.appspotmail.com

Tested on:

commit: 4bedfb31 mm,page_owner: maintain own list of stack_rec..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel config: https://syzkaller.appspot.com/x/.config?x=527195e149aa3091

dashboard link: https://syzkaller.appspot.com/bug?extid=70f57d8a3ae84934c003
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

[Stefan Hajnoczi]

Good, that was the expected last working commit. Here is the next commit
(it should fail):

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

bcore: registered new interface driver viperboard

[ 7.297712][ T1] usbcore: registered new interface driver dln2
[ 7.299149][ T1] usbcore: registered new interface driver pn533_usb
[ 7.304759][ T924] kworker/u4:1 (924) used greatest stack depth: 22768 bytes left
[ 7.308971][ T1] nfcsim 0.2 initialized
[ 7.310068][ T1] usbcore: registered new interface driver port100
[ 7.311312][ T1] usbcore: registered new interface driver nfcmrvl
[ 7.318405][ T1] Loading iSCSI transport class v2.0-870.
[ 7.334687][ T1] virtio_scsi virtio0: 1/0/0 default/read/poll queues
[ 7.344927][ T1] ------------[ cut here ]------------
[ 7.345739][ T1] refcount_t: decrement hit 0; leaking memory.
[ 7.346982][ T1] WARNING: CPU: 0 PID: 1 at lib/refcount.c:31 refcount_warn_saturate+0xfa/0x1d0
[ 7.348761][ T1] Modules linked in:
[ 7.349418][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.8.0-rc5-syzkaller-00257-g217b2119b9e2 #0
[ 7.351070][ T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
[ 7.352824][ T1] RIP: 0010:refcount_warn_saturate+0xfa/0x1d0
[ 7.353979][ T1] Code: b2 00 00 00 e8 97 2d fc fc 5b 5d c3 cc cc cc cc e8 8b 2d fc fc c6 05 0d d9 d6 0a 01 90 48 c7 c7 a0 46 fd 8b e8 e7 2c c0 fc 90 <0f> 0b 90 90 eb d9 e8 6b 2d fc fc c6 05 ea d8 d6 0a 01 90 48 c7 c7
[ 7.358181][ T1] RSP: 0000:ffffc90000066e10 EFLAGS: 00010246
[ 7.360206][ T1] RAX: 67b097fa09053300 RBX: ffff88814073377c RCX: ffff8880166c0000
[ 7.362234][ T1] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 7.363496][ T1] RBP: 0000000000000004 R08: ffffffff81589d62 R09: 1ffff9200000cd14
[ 7.365139][ T1] R10: dffffc0000000000 R11: fffff5200000cd15 R12: ffffea000501edc0
[ 7.366612][ T1] R13: ffffea000501edc8 R14: 1ffffd4000a03db9 R15: 0000000000000000
[ 7.368171][ T1] FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
[ 7.370111][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7.371030][ T1] CR2: ffff88823ffff000 CR3: 000000000df34000 CR4: 00000000003506f0
[ 7.372121][ T1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 7.373506][ T1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 7.374889][ T1] Call Trace:
[ 7.375371][ T1] <TASK>
[ 7.375798][ T1] ? __warn+0x162/0x4b0
[ 7.376442][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 7.377482][ T1] ? report_bug+0x2b3/0x500
[ 7.378161][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 7.379268][ T1] ? handle_bug+0x3e/0x70
[ 7.379887][ T1] ? exc_invalid_op+0x1a/0x50
[ 7.380563][ T1] ? asm_exc_invalid_op+0x1a/0x20
[ 7.381253][ T1] ? __warn_printk+0x292/0x360
[ 7.381912][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 7.382752][ T1] __free_pages_ok+0xc36/0xd60
[ 7.384180][ T1] make_alloc_exact+0xc4/0x140
[ 7.385037][ T1] vring_alloc_queue_split+0x20a/0x600
[ 7.386037][ T1] ? __pfx_vring_alloc_queue_split+0x10/0x10
[ 7.387029][ T1] ? vp_find_vqs+0x4c/0x4e0
[ 7.387719][ T1] ? virtscsi_probe+0x3ea/0xf60
[ 7.388408][ T1] ? virtio_dev_probe+0x991/0xaf0
[ 7.389665][ T1] ? really_probe+0x29e/0xc50
[ 7.390429][ T1] ? driver_probe_device+0x50/0x430
[ 7.391176][ T1] vring_create_virtqueue_split+0xc6/0x310
[ 7.392014][ T1] ? ret_from_fork+0x4b/0x80
[ 7.392800][ T1] ? __pfx_vring_create_virtqueue_split+0x10/0x10
[ 7.394115][ T1] vring_create_virtqueue+0xca/0x110
[ 7.395151][ T1] ? __pfx_vp_notify+0x10/0x10
[ 7.395888][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.396674][ T1] setup_vq+0xe9/0x2d0
[ 7.397283][ T1] ? __pfx_vp_notify+0x10/0x10
[ 7.397938][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.398806][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.399938][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.400951][ T1] vp_setup_vq+0xbf/0x330
[ 7.401889][ T1] ? __pfx_vp_config_changed+0x10/0x10
[ 7.403092][ T1] ? ioread16+0x2f/0x90
[ 7.403909][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.405136][ T1] vp_find_vqs_msix+0x8b2/0xc80
[ 7.405892][ T1] vp_find_vqs+0x4c/0x4e0
[ 7.406823][ T1] virtscsi_init+0x8db/0xd00
[ 7.407669][ T1] ? __pfx_virtscsi_init+0x10/0x10
[ 7.408413][ T1] ? __pfx_default_calc_sets+0x10/0x10
[ 7.409369][ T1] ? scsi_host_alloc+0xa57/0xea0
[ 7.410333][ T1] ? vp_get+0xfd/0x140
[ 7.410899][ T1] virtscsi_probe+0x3ea/0xf60
[ 7.411673][ T1] ? __pfx_virtscsi_probe+0x10/0x10
[ 7.412520][ T1] ? kernfs_add_one+0x159/0x8b0
[ 7.413222][ T1] ? virtio_no_restricted_mem_acc+0x9/0x10
[ 7.414081][ T1] ? virtio_features_ok+0x10c/0x270
[ 7.414875][ T1] virtio_dev_probe+0x991/0xaf0
[ 7.415574][ T1] ? __pfx_virtio_dev_probe+0x10/0x10
[ 7.416501][ T1] really_probe+0x29e/0xc50
[ 7.417330][ T1] __driver_probe_device+0x1a2/0x3e0
[ 7.418134][ T1] driver_probe_device+0x50/0x430
[ 7.418922][ T1] __driver_attach+0x45f/0x710
[ 7.419731][ T1] ? __pfx___driver_attach+0x10/0x10
[ 7.420653][ T1] bus_for_each_dev+0x239/0x2b0
[ 7.421541][ T1] ? __pfx___driver_attach+0x10/0x10
[ 7.422345][ T1] ? __pfx_bus_for_each_dev+0x10/0x10
[ 7.423094][ T1] ? do_raw_spin_unlock+0x13b/0x8b0
[ 7.423964][ T1] bus_add_driver+0x347/0x620
[ 7.424702][ T1] driver_register+0x23a/0x320
[ 7.425353][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 7.426126][ T1] virtio_scsi_init+0x65/0xe0
[ 7.426855][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 7.427617][ T1] do_one_initcall+0x238/0x830
[ 7.428285][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 7.429095][ T1] ? __pfx_do_one_initcall+0x10/0x10
[ 7.430084][ T1] ? lockdep_hardirqs_on_prepare+0x43c/0x780
[ 7.431238][ T1] ? __pfx_parse_args+0x10/0x10
[ 7.431953][ T1] ? do_initcalls+0x1c/0x80
[ 7.432616][ T1] ? rcu_is_watching+0x15/0xb0
[ 7.433413][ T1] do_initcall_level+0x157/0x210
[ 7.434175][ T1] do_initcalls+0x3f/0x80
[ 7.434918][ T1] kernel_init_freeable+0x42f/0x5d0
[ 7.435664][ T1] ? __pfx_kernel_init_freeable+0x10/0x10
[ 7.436745][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 7.437747][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.438487][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.439268][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.439947][ T1] kernel_init+0x1d/0x2b0
[ 7.440600][ T1] ret_from_fork+0x4b/0x80
[ 7.441572][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.442531][ T1] ret_from_fork_asm+0x1b/0x30
[ 7.443322][ T1] </TASK>
[ 7.443865][ T1] Kernel panic - not syncing: kernel: panic_on_warn set ...
[ 7.444976][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.8.0-rc5-syzkaller-00257-g217b2119b9e2 #0
[ 7.446451][ T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
[ 7.447782][ T1] Call Trace:
[ 7.448300][ T1] <TASK>
[ 7.448752][ T1] dump_stack_lvl+0x1e7/0x2e0
[ 7.449206][ T1] ? __pfx_dump_stack_lvl+0x10/0x10
[ 7.449206][ T1] ? __pfx__printk+0x10/0x10
[ 7.449206][ T1] ? _printk+0xd5/0x120
[ 7.449206][ T1] ? vscnprintf+0x5d/0x90
[ 7.449206][ T1] panic+0x349/0x860
[ 7.449206][ T1] ? __warn+0x171/0x4b0
[ 7.449206][ T1] ? __pfx_panic+0x10/0x10
[ 7.449206][ T1] ? show_trace_log_lvl+0x4e4/0x520
[ 7.449206][ T1] ? ret_from_fork_asm+0x1b/0x30
[ 7.449206][ T1] __warn+0x31c/0x4b0
[ 7.449206][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 7.449206][ T1] report_bug+0x2b3/0x500
[ 7.449206][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 7.458645][ T1] handle_bug+0x3e/0x70
[ 7.458645][ T1] exc_invalid_op+0x1a/0x50
[ 7.458645][ T1] asm_exc_invalid_op+0x1a/0x20
[ 7.458645][ T1] RIP: 0010:refcount_warn_saturate+0xfa/0x1d0
[ 7.458645][ T1] Code: b2 00 00 00 e8 97 2d fc fc 5b 5d c3 cc cc cc cc e8 8b 2d fc fc c6 05 0d d9 d6 0a 01 90 48 c7 c7 a0 46 fd 8b e8 e7 2c c0 fc 90 <0f> 0b 90 90 eb d9 e8 6b 2d fc fc c6 05 ea d8 d6 0a 01 90 48 c7 c7
[ 7.458645][ T1] RSP: 0000:ffffc90000066e10 EFLAGS: 00010246
[ 7.458645][ T1] RAX: 67b097fa09053300 RBX: ffff88814073377c RCX: ffff8880166c0000
[ 7.458645][ T1] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 7.468739][ T1] RBP: 0000000000000004 R08: ffffffff81589d62 R09: 1ffff9200000cd14
[ 7.468739][ T1] R10: dffffc0000000000 R11: fffff5200000cd15 R12: ffffea000501edc0
[ 7.468739][ T1] R13: ffffea000501edc8 R14: 1ffffd4000a03db9 R15: 0000000000000000
[ 7.468739][ T1] ? __warn_printk+0x292/0x360
[ 7.468739][ T1] __free_pages_ok+0xc36/0xd60
[ 7.468739][ T1] make_alloc_exact+0xc4/0x140
[ 7.468739][ T1] vring_alloc_queue_split+0x20a/0x600
[ 7.468739][ T1] ? __pfx_vring_alloc_queue_split+0x10/0x10
[ 7.468739][ T1] ? vp_find_vqs+0x4c/0x4e0
[ 7.468739][ T1] ? virtscsi_probe+0x3ea/0xf60
[ 7.478647][ T1] ? virtio_dev_probe+0x991/0xaf0
[ 7.478647][ T1] ? really_probe+0x29e/0xc50
[ 7.478647][ T1] ? driver_probe_device+0x50/0x430
[ 7.478647][ T1] vring_create_virtqueue_split+0xc6/0x310
[ 7.478647][ T1] ? ret_from_fork+0x4b/0x80
[ 7.478647][ T1] ? __pfx_vring_create_virtqueue_split+0x10/0x10
[ 7.478647][ T1] vring_create_virtqueue+0xca/0x110
[ 7.478647][ T1] ? __pfx_vp_notify+0x10/0x10
[ 7.478647][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.478647][ T1] setup_vq+0xe9/0x2d0
[ 7.478647][ T1] ? __pfx_vp_notify+0x10/0x10
[ 7.478647][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.488714][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.488714][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.488714][ T1] vp_setup_vq+0xbf/0x330
[ 7.488714][ T1] ? __pfx_vp_config_changed+0x10/0x10
[ 7.488714][ T1] ? ioread16+0x2f/0x90
[ 7.488714][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.488714][ T1] vp_find_vqs_msix+0x8b2/0xc80
[ 7.488714][ T1] vp_find_vqs+0x4c/0x4e0
[ 7.488714][ T1] virtscsi_init+0x8db/0xd00
[ 7.488714][ T1] ? __pfx_virtscsi_init+0x10/0x10
[ 7.488714][ T1] ? __pfx_default_calc_sets+0x10/0x10
[ 7.498614][ T1] ? scsi_host_alloc+0xa57/0xea0
[ 7.498614][ T1] ? vp_get+0xfd/0x140
[ 7.498614][ T1] virtscsi_probe+0x3ea/0xf60
[ 7.498614][ T1] ? __pfx_virtscsi_probe+0x10/0x10
[ 7.498614][ T1] ? kernfs_add_one+0x159/0x8b0
[ 7.498614][ T1] ? virtio_no_restricted_mem_acc+0x9/0x10
[ 7.498614][ T1] ? virtio_features_ok+0x10c/0x270
[ 7.498614][ T1] virtio_dev_probe+0x991/0xaf0
[ 7.498614][ T1] ? __pfx_virtio_dev_probe+0x10/0x10
[ 7.498614][ T1] really_probe+0x29e/0xc50
[ 7.498614][ T1] __driver_probe_device+0x1a2/0x3e0
[ 7.508689][ T1] driver_probe_device+0x50/0x430
[ 7.508689][ T1] __driver_attach+0x45f/0x710
[ 7.508689][ T1] ? __pfx___driver_attach+0x10/0x10
[ 7.508689][ T1] bus_for_each_dev+0x239/0x2b0
[ 7.508689][ T1] ? __pfx___driver_attach+0x10/0x10
[ 7.508689][ T1] ? __pfx_bus_for_each_dev+0x10/0x10
[ 7.508689][ T1] ? do_raw_spin_unlock+0x13b/0x8b0
[ 7.508689][ T1] bus_add_driver+0x347/0x620
[ 7.508689][ T1] driver_register+0x23a/0x320
[ 7.508689][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 7.508689][ T1] virtio_scsi_init+0x65/0xe0
[ 7.518645][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 7.518645][ T1] do_one_initcall+0x238/0x830
[ 7.518645][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 7.518645][ T1] ? __pfx_do_one_initcall+0x10/0x10
[ 7.518645][ T1] ? lockdep_hardirqs_on_prepare+0x43c/0x780
[ 7.518645][ T1] ? __pfx_parse_args+0x10/0x10
[ 7.518645][ T1] ? do_initcalls+0x1c/0x80
[ 7.518645][ T1] ? rcu_is_watching+0x15/0xb0
[ 7.518645][ T1] do_initcall_level+0x157/0x210
[ 7.518645][ T1] do_initcalls+0x3f/0x80
[ 7.518645][ T1] kernel_init_freeable+0x42f/0x5d0
[ 7.528806][ T1] ? __pfx_kernel_init_freeable+0x10/0x10
[ 7.528806][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 7.528806][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.528806][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.528806][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.528806][ T1] kernel_init+0x1d/0x2b0
[ 7.528806][ T1] ret_from_fork+0x4b/0x80
[ 7.528806][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.528806][ T1] ret_from_fork_asm+0x1b/0x30
[ 7.528806][ T1] </TASK>
[ 7.528806][ T1] Kernel Offset: disabled
[ 7.528806][ T1] Rebooting in 86400 seconds..


syzkaller build log:
go env (err=<nil>)
GO111MODULE='auto'
GOARCH='amd64'
GOBIN=''
GOCACHE='/syzkaller/.cache/go-build'
GOENV='/syzkaller/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMODCACHE='/syzkaller/jobs/linux/gopath/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/syzkaller/jobs/linux/gopath'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.21.4'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOMOD='/syzkaller/jobs/linux/gopath/src/github.com/google/syzkaller/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build2530895313=/tmp/go-build -gno-record-gcc-switches'

git status (err=<nil>)
HEAD detached at 6753db5cd
nothing to commit, working tree clean


tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
go list -f '{{.Stale}}' ./sys/syz-sysgen | grep -q false || go install ./sys/syz-sysgen
make .descriptions
tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
bin/syz-sysgen
touch .descriptions
GOOS=linux GOARCH=amd64 go build "-ldflags=-s -w -X github.com/google/syzkaller/prog.GitRevision=6753db5cdc04330ec9d1a5116b890c19481d69b3 -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240320-145051'" "-tags=syz_target syz_os_linux syz_arch_amd64 " -o ./bin/linux_amd64/syz-fuzzer github.com/google/syzkaller/syz-fuzzer
GOOS=linux GOARCH=amd64 go build "-ldflags=-s -w -X github.com/google/syzkaller/prog.GitRevision=6753db5cdc04330ec9d1a5116b890c19481d69b3 -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240320-145051'" "-tags=syz_target syz_os_linux syz_arch_amd64 " -o ./bin/linux_amd64/syz-execprog github.com/google/syzkaller/tools/syz-execprog
GOOS=linux GOARCH=amd64 go build "-ldflags=-s -w -X github.com/google/syzkaller/prog.GitRevision=6753db5cdc04330ec9d1a5116b890c19481d69b3 -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240320-145051'" "-tags=syz_target syz_os_linux syz_arch_amd64 " -o ./bin/linux_amd64/syz-stress github.com/google/syzkaller/tools/syz-stress
mkdir -p ./bin/linux_amd64
gcc -o ./bin/linux_amd64/syz-executor executor/executor.cc \
-m64 -O2 -pthread -Wall -Werror -Wparentheses -Wunused-const-variable -Wframe-larger-than=16384 -Wno-stringop-overflow -Wno-array-bounds -Wno-format-overflow -Wno-unused-but-set-variable -Wno-unused-command-line-argument -static-pie -fpermissive -w -DGOOS_linux=1 -DGOARCH_amd64=1 \
-DHOSTGOOS_linux=1 -DGIT_REVISION=\"6753db5cdc04330ec9d1a5116b890c19481d69b3\"


Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=1254e231180000


Tested on:

commit: 217b2119 mm,page_owner: implement the tracking of the ..

[Stefan Hajnoczi]

On Thu, Mar 21, 2024 at 08:52:03AM -0700, syzbot wrote:
> Hello,
>
> syzbot tried to test the proposed patch but the build/boot failed:
>
> bcore: registered new interface driver viperboard
> [ 7.297712][ T1] usbcore: registered new interface driver dln2
> [ 7.299149][ T1] usbcore: registered new interface driver pn533_usb
> [ 7.304759][ T924] kworker/u4:1 (924) used greatest stack depth: 22768 bytes left
> [ 7.308971][ T1] nfcsim 0.2 initialized
> [ 7.310068][ T1] usbcore: registered new interface driver port100
> [ 7.311312][ T1] usbcore: registered new interface driver nfcmrvl
> [ 7.318405][ T1] Loading iSCSI transport class v2.0-870.
> [ 7.334687][ T1] virtio_scsi virtio0: 1/0/0 default/read/poll queues
> [ 7.344927][ T1] ------------[ cut here ]------------
> [ 7.345739][ T1] refcount_t: decrement hit 0; leaking memory.

This confirms that the following commit introduced this issue:

commit 217b2119b9e260609958db413876f211038f00ee
Author: Oscar Salvador <osal...@suse.de>
Date: Thu Feb 15 22:59:04 2024 +0100

mm,page_owner: implement the tracking of the stacks count

Mike: thanks for pointing out the fix that Oscar is working on!

Oscar: Please add the syzbot trailer to the next revision of your
"[PATCH v2 0/2] page_owner: Refcount fixups" series so this issue can be
closed.

[Tetsuo Handa]

#syz fix: mm,page_owner: Fix refcount imbalance

[Tetsuo Handa]

#syz fix: mm,page_owner: fix refcount imbalance