[syzbot] [net?] possible deadlock in unix_del_edges

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2b3d5988ae2c Add linux-next specific files for 20240404
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=16c79d29180000
kernel config: https://syzkaller.appspot.com/x/.config?x=9c48fd2523cdee5e
dashboard link: https://syzkaller.appspot.com/bug?extid=7f7f201cc2668a8fd169
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/136270ed2c7b/disk-2b3d5988.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/466d2f7c1952/vmlinux-2b3d5988.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7dfaf3959891/bzImage-2b3d5988.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7f7f20...@syzkaller.appspotmail.com

============================================
WARNING: possible recursive locking detected
6.9.0-rc2-next-20240404-syzkaller #0 Not tainted
--------------------------------------------
kworker/u8:8/2805 is trying to acquire lock:
ffffffff8f6dc178 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffffff8f6dc178 (unix_gc_lock){+.+.}-{2:2}, at: unix_del_edges+0x30/0x590 net/unix/garbage.c:227

but task is already holding lock:
ffffffff8f6dc178 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffffff8f6dc178 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0xc5/0x1830 net/unix/garbage.c:547

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(unix_gc_lock);
lock(unix_gc_lock);

*** DEADLOCK ***

May be due to missing lock nesting notation

4 locks held by kworker/u8:8/2805:
#0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3193 [inline]
#0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3299
#1: ffffc9000a25fd00 (unix_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3194 [inline]
#1: ffffc9000a25fd00 (unix_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3299
#2: ffffffff8f6dc178 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#2: ffffffff8f6dc178 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0xc5/0x1830 net/unix/garbage.c:547
#3: ffff88802317e118 (rlock-AF_UNIX){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#3: ffff88802317e118 (rlock-AF_UNIX){+.+.}-{2:2}, at: unix_collect_skb+0xb8/0x700 net/unix/garbage.c:343

stack backtrace:
CPU: 0 PID: 2805 Comm: kworker/u8:8 Not tainted 6.9.0-rc2-next-20240404-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events_unbound __unix_gc
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
check_deadlock kernel/locking/lockdep.c:3062 [inline]
validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856
__lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
unix_del_edges+0x30/0x590 net/unix/garbage.c:227
unix_destroy_fpl+0x59/0x210 net/unix/garbage.c:286
unix_detach_fds net/unix/af_unix.c:1816 [inline]
unix_destruct_scm+0x13e/0x210 net/unix/af_unix.c:1873
skb_release_head_state+0x100/0x250 net/core/skbuff.c:1162
skb_release_all net/core/skbuff.c:1173 [inline]
__kfree_skb net/core/skbuff.c:1189 [inline]
kfree_skb_reason+0x16d/0x3b0 net/core/skbuff.c:1225
kfree_skb include/linux/skbuff.h:1262 [inline]
unix_collect_skb+0x5e4/0x700 net/unix/garbage.c:361
unix_walk_scc_fast net/unix/garbage.c:533 [inline]
__unix_gc+0x686/0x1830 net/unix/garbage.c:557
process_one_work kernel/workqueue.c:3218 [inline]
process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299
worker_thread+0x86d/0xd70 kernel/workqueue.c:3380
kthread+0x2f0/0x390 kernel/kthread.c:388
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.
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

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 2b3d5988ae2c Add linux-next specific files for 20240404
git tree: linux-next

console output: https://syzkaller.appspot.com/x/log.txt?x=13114d8d180000

kernel config: https://syzkaller.appspot.com/x/.config?x=9c48fd2523cdee5e
dashboard link: https://syzkaller.appspot.com/bug?extid=7f7f201cc2668a8fd169
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=113c7103180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1133aaa9180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/136270ed2c7b/disk-2b3d5988.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/466d2f7c1952/vmlinux-2b3d5988.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7dfaf3959891/bzImage-2b3d5988.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7f7f20...@syzkaller.appspotmail.com

============================================
WARNING: possible recursive locking detected
6.9.0-rc2-next-20240404-syzkaller #0 Not tainted
--------------------------------------------

kworker/u8:3/51 is trying to acquire lock:

ffffffff8f6dc178 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffffff8f6dc178 (unix_gc_lock){+.+.}-{2:2}, at: unix_del_edges+0x30/0x590 net/unix/garbage.c:227

but task is already holding lock:
ffffffff8f6dc178 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffffff8f6dc178 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0xc5/0x1830 net/unix/garbage.c:547

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(unix_gc_lock);
lock(unix_gc_lock);

*** DEADLOCK ***

May be due to missing lock nesting notation

4 locks held by kworker/u8:3/51:

#0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3193 [inline]
#0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3299

#1: ffffc90000bb7d00 (unix_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3194 [inline]
#1: ffffc90000bb7d00 (unix_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3299

#2: ffffffff8f6dc178 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#2: ffffffff8f6dc178 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0xc5/0x1830 net/unix/garbage.c:547

#3: ffff88802bd76118 (rlock-AF_UNIX){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#3: ffff88802bd76118 (rlock-AF_UNIX){+.+.}-{2:2}, at: unix_collect_skb+0xb8/0x700 net/unix/garbage.c:343

stack backtrace:
CPU: 0 PID: 51 Comm: kworker/u8:3 Not tainted 6.9.0-rc2-next-20240404-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events_unbound __unix_gc
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
check_deadlock kernel/locking/lockdep.c:3062 [inline]
validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856
__lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
unix_del_edges+0x30/0x590 net/unix/garbage.c:227
unix_destroy_fpl+0x59/0x210 net/unix/garbage.c:286
unix_detach_fds net/unix/af_unix.c:1816 [inline]
unix_destruct_scm+0x13e/0x210 net/unix/af_unix.c:1873
skb_release_head_state+0x100/0x250 net/core/skbuff.c:1162
skb_release_all net/core/skbuff.c:1173 [inline]
__kfree_skb net/core/skbuff.c:1189 [inline]
kfree_skb_reason+0x16d/0x3b0 net/core/skbuff.c:1225
kfree_skb include/linux/skbuff.h:1262 [inline]
unix_collect_skb+0x5e4/0x700 net/unix/garbage.c:361

__unix_walk_scc net/unix/garbage.c:481 [inline]
unix_walk_scc net/unix/garbage.c:506 [inline]
__unix_gc+0x108c/0x1830 net/unix/garbage.c:559

process_one_work kernel/workqueue.c:3218 [inline]
process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299
worker_thread+0x86d/0xd70 kernel/workqueue.c:3380
kthread+0x2f0/0x390 kernel/kthread.c:388
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>


---

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

[Kuniyuki Iwashima]

From: syzbot <syzbot+7f7f20...@syzkaller.appspotmail.com>
Date: Thu, 04 Apr 2024 09:13:26 -0700

It seems OOB skb has already lost a refcount but not cleared ?

Will look into the repro today.

Thanks!

[Kuniyuki Iwashima]

From: syzbot <syzbot+7f7f20...@syzkaller.appspotmail.com>
Date: Thu, 04 Apr 2024 09:13:26 -0700

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git main

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 61ecfa9c9c6b..12851dadcd4c 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -2619,6 +2619,7 @@ static struct sk_buff *manage_oob(struct sk_buff *skb, struct sock *sk,
}
} else if (!(flags & MSG_PEEK)) {
skb_unlink(skb, &sk->sk_receive_queue);
+ WRITE_ONCE(u->oob_skb, NULL);
consume_skb(skb);
skb = skb_peek(&sk->sk_receive_queue);
}

[Hillf Danton]

On Thu, 04 Apr 2024 09:13:26 -0700

> syzbot has found a reproducer for the following issue on:
>
> HEAD commit: 2b3d5988ae2c Add linux-next specific files for 20240404
> git tree: linux-next

> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1133aaa9180000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 2b3d5988ae2c

--- x/net/unix/garbage.c
+++ y/net/unix/garbage.c
@@ -358,7 +358,7 @@ static void unix_collect_skb(struct list

#if IS_ENABLED(CONFIG_AF_UNIX_OOB)
if (u->oob_skb) {
- kfree_skb(u->oob_skb);
+ __skb_queue_tail(hitlist, u->oob_skb);
u->oob_skb = NULL;
}
#endif
--

[syzbot]

Hello,

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

8.212120][ T1] usbcore: registered new interface driver dln2
[ 8.213619][ T1] usbcore: registered new interface driver pn533_usb
[ 8.219690][ T1] nfcsim 0.2 initialized
[ 8.220521][ T1] usbcore: registered new interface driver port100
[ 8.221680][ T1] usbcore: registered new interface driver nfcmrvl
[ 8.228707][ T1] Loading iSCSI transport class v2.0-870.
[ 8.246261][ T1] virtio_scsi virtio0: 1/0/0 default/read/poll queues
[ 8.257029][ T1] ------------[ cut here ]------------
[ 8.258477][ T1] refcount_t: decrement hit 0; leaking memory.
[ 8.260137][ T1] WARNING: CPU: 0 PID: 1 at lib/refcount.c:31 refcount_warn_saturate+0xfa/0x1d0
[ 8.261845][ T1] Modules linked in:
[ 8.262516][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.9.0-rc1-syzkaller-00587-g1148c4098e91-dirty #0
[ 8.264650][ T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
[ 8.266787][ T1] RIP: 0010:refcount_warn_saturate+0xfa/0x1d0
[ 8.267720][ T1] Code: b2 00 00 00 e8 67 bc e9 fc 5b 5d c3 cc cc cc cc e8 5b bc e9 fc c6 05 01 d6 e7 0a 01 90 48 c7 c7 e0 33 1f 8c e8 97 58 ac fc 90 <0f> 0b 90 90 eb d9 e8 3b bc e9 fc c6 05 de d5 e7 0a 01 90 48 c7 c7
[ 8.270554][ T1] RSP: 0000:ffffc90000066e18 EFLAGS: 00010246
[ 8.271418][ T1] RAX: 974e1ecb508eeb00 RBX: ffff8880215be1cc RCX: ffff8880166d0000
[ 8.272570][ T1] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
[ 8.274748][ T1] RBP: 0000000000000004 R08: ffffffff815800a2 R09: fffffbfff1c396e0
[ 8.276442][ T1] R10: dffffc0000000000 R11: fffffbfff1c396e0 R12: ffffea000085edc0
[ 8.278522][ T1] R13: ffffea000085edc8 R14: 1ffffd400010bdb9 R15: 0000000000000000
[ 8.279919][ T1] FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
[ 8.281604][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 8.282666][ T1] CR2: ffff88823ffff000 CR3: 000000000e132000 CR4: 00000000003506f0
[ 8.284991][ T1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 8.286484][ T1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 8.287637][ T1] Call Trace:
[ 8.288094][ T1] <TASK>
[ 8.288507][ T1] ? __warn+0x163/0x4e0
[ 8.289131][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.290261][ T1] ? report_bug+0x2b3/0x500
[ 8.291100][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.292002][ T1] ? handle_bug+0x3e/0x70
[ 8.292662][ T1] ? exc_invalid_op+0x1a/0x50
[ 8.294170][ T1] ? asm_exc_invalid_op+0x1a/0x20
[ 8.295054][ T1] ? __warn_printk+0x292/0x360
[ 8.295831][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.296625][ T1] ? refcount_warn_saturate+0xf9/0x1d0
[ 8.297711][ T1] __free_pages_ok+0xc60/0xd90
[ 8.298434][ T1] make_alloc_exact+0xa3/0xf0
[ 8.299241][ T1] vring_alloc_queue_split+0x20a/0x600
[ 8.300331][ T1] ? __pfx_vring_alloc_queue_split+0x10/0x10
[ 8.301458][ T1] ? vp_find_vqs+0x4c/0x4e0
[ 8.302182][ T1] ? virtscsi_probe+0x3ea/0xf60
[ 8.303012][ T1] ? virtio_dev_probe+0x991/0xaf0
[ 8.303941][ T1] ? really_probe+0x2b8/0xad0
[ 8.304920][ T1] ? driver_probe_device+0x50/0x430
[ 8.305769][ T1] vring_create_virtqueue_split+0xc6/0x310
[ 8.306675][ T1] ? ret_from_fork+0x4b/0x80
[ 8.307401][ T1] ? __pfx_vring_create_virtqueue_split+0x10/0x10
[ 8.308459][ T1] vring_create_virtqueue+0xca/0x110
[ 8.309400][ T1] ? __pfx_vp_notify+0x10/0x10
[ 8.310185][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.311281][ T1] setup_vq+0xe9/0x2d0
[ 8.311917][ T1] ? __pfx_vp_notify+0x10/0x10
[ 8.312811][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.313707][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.314501][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.315275][ T1] vp_setup_vq+0xbf/0x330
[ 8.315908][ T1] ? __pfx_vp_config_changed+0x10/0x10
[ 8.316689][ T1] ? ioread16+0x2f/0x90
[ 8.317266][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.318047][ T1] vp_find_vqs_msix+0x8b2/0xc80
[ 8.318749][ T1] vp_find_vqs+0x4c/0x4e0
[ 8.319372][ T1] virtscsi_init+0x8db/0xd00
[ 8.320086][ T1] ? __pfx_virtscsi_init+0x10/0x10
[ 8.320818][ T1] ? __pfx_default_calc_sets+0x10/0x10
[ 8.322142][ T1] ? scsi_host_alloc+0xa57/0xea0
[ 8.322957][ T1] ? vp_get+0xfd/0x140
[ 8.323715][ T1] virtscsi_probe+0x3ea/0xf60
[ 8.324363][ T1] ? __pfx_virtscsi_probe+0x10/0x10
[ 8.325113][ T1] ? kernfs_add_one+0x156/0x8b0
[ 8.325945][ T1] ? virtio_no_restricted_mem_acc+0x9/0x10
[ 8.326777][ T1] ? virtio_features_ok+0x10c/0x270
[ 8.327803][ T1] virtio_dev_probe+0x991/0xaf0
[ 8.328575][ T1] ? __pfx_virtio_dev_probe+0x10/0x10
[ 8.329366][ T1] really_probe+0x2b8/0xad0
[ 8.330008][ T1] __driver_probe_device+0x1a2/0x390
[ 8.330931][ T1] driver_probe_device+0x50/0x430
[ 8.331626][ T1] __driver_attach+0x45f/0x710
[ 8.332858][ T1] ? __pfx___driver_attach+0x10/0x10
[ 8.333710][ T1] bus_for_each_dev+0x239/0x2b0
[ 8.334423][ T1] ? __pfx___driver_attach+0x10/0x10
[ 8.335724][ T1] ? __pfx_bus_for_each_dev+0x10/0x10
[ 8.336563][ T1] ? do_raw_spin_unlock+0x13c/0x8b0
[ 8.337303][ T1] bus_add_driver+0x347/0x620
[ 8.337947][ T1] driver_register+0x23a/0x320
[ 8.338742][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.339660][ T1] virtio_scsi_init+0x65/0xe0
[ 8.340487][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.341518][ T1] do_one_initcall+0x248/0x880
[ 8.342203][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.343126][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 8.344315][ T1] ? __pfx_do_one_initcall+0x10/0x10
[ 8.345151][ T1] ? __pfx_parse_args+0x10/0x10
[ 8.345841][ T1] ? do_initcalls+0x1c/0x80
[ 8.347111][ T1] ? rcu_is_watching+0x15/0xb0
[ 8.347855][ T1] do_initcall_level+0x157/0x210
[ 8.348760][ T1] do_initcalls+0x3f/0x80
[ 8.349423][ T1] kernel_init_freeable+0x435/0x5d0
[ 8.350160][ T1] ? __pfx_kernel_init_freeable+0x10/0x10
[ 8.351033][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 8.351922][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.352603][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.353421][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.354169][ T1] kernel_init+0x1d/0x2b0
[ 8.355176][ T1] ret_from_fork+0x4b/0x80
[ 8.356039][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.356939][ T1] ret_from_fork_asm+0x1a/0x30
[ 8.357632][ T1] </TASK>
[ 8.358056][ T1] Kernel panic - not syncing: kernel: panic_on_warn set ...
[ 8.359262][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.9.0-rc1-syzkaller-00587-g1148c4098e91-dirty #0
[ 8.360836][ T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
[ 8.362851][ T1] Call Trace:
[ 8.363394][ T1] <TASK>
[ 8.363394][ T1] dump_stack_lvl+0x241/0x360
[ 8.363394][ T1] ? __pfx_dump_stack_lvl+0x10/0x10
[ 8.363394][ T1] ? __pfx__printk+0x10/0x10
[ 8.363394][ T1] ? _printk+0xd5/0x120
[ 8.363394][ T1] ? vscnprintf+0x5d/0x90
[ 8.363394][ T1] panic+0x349/0x860
[ 8.363394][ T1] ? __warn+0x172/0x4e0
[ 8.363394][ T1] ? __pfx_panic+0x10/0x10
[ 8.363394][ T1] ? show_trace_log_lvl+0x4e6/0x520
[ 8.363394][ T1] ? ret_from_fork_asm+0x1a/0x30
[ 8.363394][ T1] __warn+0x346/0x4e0
[ 8.363394][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.363394][ T1] report_bug+0x2b3/0x500
[ 8.363394][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.363394][ T1] handle_bug+0x3e/0x70
[ 8.363394][ T1] exc_invalid_op+0x1a/0x50
[ 8.363394][ T1] asm_exc_invalid_op+0x1a/0x20
[ 8.363394][ T1] RIP: 0010:refcount_warn_saturate+0xfa/0x1d0
[ 8.363394][ T1] Code: b2 00 00 00 e8 67 bc e9 fc 5b 5d c3 cc cc cc cc e8 5b bc e9 fc c6 05 01 d6 e7 0a 01 90 48 c7 c7 e0 33 1f 8c e8 97 58 ac fc 90 <0f> 0b 90 90 eb d9 e8 3b bc e9 fc c6 05 de d5 e7 0a 01 90 48 c7 c7
[ 8.363394][ T1] RSP: 0000:ffffc90000066e18 EFLAGS: 00010246
[ 8.363394][ T1] RAX: 974e1ecb508eeb00 RBX: ffff8880215be1cc RCX: ffff8880166d0000
[ 8.363394][ T1] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
[ 8.363394][ T1] RBP: 0000000000000004 R08: ffffffff815800a2 R09: fffffbfff1c396e0
[ 8.363394][ T1] R10: dffffc0000000000 R11: fffffbfff1c396e0 R12: ffffea000085edc0
[ 8.363394][ T1] R13: ffffea000085edc8 R14: 1ffffd400010bdb9 R15: 0000000000000000
[ 8.363394][ T1] ? __warn_printk+0x292/0x360
[ 8.363394][ T1] ? refcount_warn_saturate+0xf9/0x1d0
[ 8.363394][ T1] __free_pages_ok+0xc60/0xd90
[ 8.363394][ T1] make_alloc_exact+0xa3/0xf0
[ 8.363394][ T1] vring_alloc_queue_split+0x20a/0x600
[ 8.363394][ T1] ? __pfx_vring_alloc_queue_split+0x10/0x10
[ 8.363394][ T1] ? vp_find_vqs+0x4c/0x4e0
[ 8.363394][ T1] ? virtscsi_probe+0x3ea/0xf60
[ 8.363394][ T1] ? virtio_dev_probe+0x991/0xaf0
[ 8.363394][ T1] ? really_probe+0x2b8/0xad0
[ 8.363394][ T1] ? driver_probe_device+0x50/0x430
[ 8.363394][ T1] vring_create_virtqueue_split+0xc6/0x310
[ 8.363394][ T1] ? ret_from_fork+0x4b/0x80
[ 8.363394][ T1] ? __pfx_vring_create_virtqueue_split+0x10/0x10
[ 8.363394][ T1] vring_create_virtqueue+0xca/0x110
[ 8.363394][ T1] ? __pfx_vp_notify+0x10/0x10
[ 8.363394][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.363394][ T1] setup_vq+0xe9/0x2d0
[ 8.363394][ T1] ? __pfx_vp_notify+0x10/0x10
[ 8.363394][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.363394][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.363394][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.363394][ T1] vp_setup_vq+0xbf/0x330
[ 8.363394][ T1] ? __pfx_vp_config_changed+0x10/0x10
[ 8.363394][ T1] ? ioread16+0x2f/0x90
[ 8.413403][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.413403][ T1] vp_find_vqs_msix+0x8b2/0xc80
[ 8.413403][ T1] vp_find_vqs+0x4c/0x4e0
[ 8.413403][ T1] virtscsi_init+0x8db/0xd00
[ 8.413403][ T1] ? __pfx_virtscsi_init+0x10/0x10
[ 8.413403][ T1] ? __pfx_default_calc_sets+0x10/0x10
[ 8.413403][ T1] ? scsi_host_alloc+0xa57/0xea0
[ 8.413403][ T1] ? vp_get+0xfd/0x140
[ 8.413403][ T1] virtscsi_probe+0x3ea/0xf60
[ 8.413403][ T1] ? __pfx_virtscsi_probe+0x10/0x10
[ 8.413403][ T1] ? kernfs_add_one+0x156/0x8b0
[ 8.413403][ T1] ? virtio_no_restricted_mem_acc+0x9/0x10
[ 8.413403][ T1] ? virtio_features_ok+0x10c/0x270
[ 8.413403][ T1] virtio_dev_probe+0x991/0xaf0
[ 8.413403][ T1] ? __pfx_virtio_dev_probe+0x10/0x10
[ 8.413403][ T1] really_probe+0x2b8/0xad0
[ 8.413403][ T1] __driver_probe_device+0x1a2/0x390
[ 8.413403][ T1] driver_probe_device+0x50/0x430
[ 8.413403][ T1] __driver_attach+0x45f/0x710
[ 8.413403][ T1] ? __pfx___driver_attach+0x10/0x10
[ 8.413403][ T1] bus_for_each_dev+0x239/0x2b0
[ 8.413403][ T1] ? __pfx___driver_attach+0x10/0x10
[ 8.413403][ T1] ? __pfx_bus_for_each_dev+0x10/0x10
[ 8.413403][ T1] ? do_raw_spin_unlock+0x13c/0x8b0
[ 8.413403][ T1] bus_add_driver+0x347/0x620
[ 8.413403][ T1] driver_register+0x23a/0x320
[ 8.413403][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.413403][ T1] virtio_scsi_init+0x65/0xe0
[ 8.413403][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.413403][ T1] do_one_initcall+0x248/0x880
[ 8.413403][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.413403][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 8.413403][ T1] ? __pfx_do_one_initcall+0x10/0x10
[ 8.413403][ T1] ? __pfx_parse_args+0x10/0x10
[ 8.413403][ T1] ? do_initcalls+0x1c/0x80
[ 8.413403][ T1] ? rcu_is_watching+0x15/0xb0
[ 8.413403][ T1] do_initcall_level+0x157/0x210
[ 8.413403][ T1] do_initcalls+0x3f/0x80
[ 8.413403][ T1] kernel_init_freeable+0x435/0x5d0
[ 8.413403][ T1] ? __pfx_kernel_init_freeable+0x10/0x10
[ 8.413403][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 8.413403][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.413403][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.413403][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.413403][ T1] kernel_init+0x1d/0x2b0
[ 8.413403][ T1] ret_from_fork+0x4b/0x80
[ 8.413403][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.413403][ T1] ret_from_fork_asm+0x1a/0x30
[ 8.413403][ T1] </TASK>
[ 8.413403][ T1] Kernel Offset: disabled
[ 8.413403][ 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-build2976360966=/tmp/go-build -gno-record-gcc-switches'

git status (err=<nil>)
HEAD detached at 0ee3535ea
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=0ee3535ea8ff21d50e44372bb1cfd147e299ab5b -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240404-085507'" "-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=0ee3535ea8ff21d50e44372bb1cfd147e299ab5b -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240404-085507'" "-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=0ee3535ea8ff21d50e44372bb1cfd147e299ab5b -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240404-085507'" "-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=\"0ee3535ea8ff21d50e44372bb1cfd147e299ab5b\"


Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=11b3cca9180000


Tested on:

commit: 1148c409 Merge branch 'selftests-net-groundwork-for-yn..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git main
kernel config: https://syzkaller.appspot.com/x/.config?x=898d2273d9f2e9d3

dashboard link: https://syzkaller.appspot.com/bug?extid=7f7f201cc2668a8fd169
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=162dcca9180000

[Kuniyuki Iwashima]

From: syzbot <syzbot+7f7f20...@syzkaller.appspotmail.com>
Date: Thu, 04 Apr 2024 09:13:26 -0700

> syzbot has found a reproducer for the following issue on:
>
> HEAD commit: 2b3d5988ae2c Add linux-next specific files for 20240404
> git tree: linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=13114d8d180000
> kernel config: https://syzkaller.appspot.com/x/.config?x=9c48fd2523cdee5e
> dashboard link: https://syzkaller.appspot.com/bug?extid=7f7f201cc2668a8fd169
> compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=113c7103180000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1133aaa9180000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/136270ed2c7b/disk-2b3d5988.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/466d2f7c1952/vmlinux-2b3d5988.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/7dfaf3959891/bzImage-2b3d5988.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+7f7f20...@syzkaller.appspotmail.com

The boot failure for the previous patch is not related to the patch.
Probably I should've specified the gc commit.

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git 4090fa373f0e763c43610853d2774b5979915959

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 61ecfa9c9c6b..d3bf9f49012d 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -2619,7 +2619,9 @@ static struct sk_buff *manage_oob(struct sk_buff *skb, struct sock *sk,

}
} else if (!(flags & MSG_PEEK)) {
skb_unlink(skb, &sk->sk_receive_queue);

- consume_skb(skb);
+ WRITE_ONCE(u->oob_skb, NULL);
+ kfree_skb(skb);
+ kfree_skb(skb);
skb = skb_peek(&sk->sk_receive_queue);
}
}

[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+7f7f20...@syzkaller.appspotmail.com

Tested on:

commit: 2b3d5988 Add linux-next specific files for 20240404
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=14d06aa9180000

kernel config: https://syzkaller.appspot.com/x/.config?x=9c48fd2523cdee5e
dashboard link: https://syzkaller.appspot.com/bug?extid=7f7f201cc2668a8fd169
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=11d94d8d180000

Note: testing is done by a robot and is best-effort only.

[syzbot]

Hello,

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

006703][ T1] usbcore: registered new interface driver dln2
[ 8.008304][ T1] usbcore: registered new interface driver pn533_usb
[ 8.015792][ T1] nfcsim 0.2 initialized
[ 8.016960][ T1] usbcore: registered new interface driver port100
[ 8.018599][ T1] usbcore: registered new interface driver nfcmrvl
[ 8.024908][ T1] Loading iSCSI transport class v2.0-870.
[ 8.043578][ T1] virtio_scsi virtio0: 1/0/0 default/read/poll queues
[ 8.053585][ T1] ------------[ cut here ]------------
[ 8.054621][ T1] refcount_t: decrement hit 0; leaking memory.
[ 8.056227][ T1] WARNING: CPU: 0 PID: 1 at lib/refcount.c:31 refcount_warn_saturate+0xfa/0x1d0
[ 8.057690][ T1] Modules linked in:
[ 8.058278][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.9.0-rc1-syzkaller-00291-g4090fa373f0e-dirty #0
[ 8.059690][ T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
[ 8.061033][ T1] RIP: 0010:refcount_warn_saturate+0xfa/0x1d0
[ 8.061863][ T1] Code: b2 00 00 00 e8 97 bb e9 fc 5b 5d c3 cc cc cc cc e8 8b bb e9 fc c6 05 2e c7 e7 0a 01 90 48 c7 c7 e0 33 1f 8c e8 c7 57 ac fc 90 <0f> 0b 90 90 eb d9 e8 6b bb e9 fc c6 05 0b c7 e7 0a 01 90 48 c7 c7
[ 8.066117][ T1] RSP: 0000:ffffc90000066e18 EFLAGS: 00010246
[ 8.067097][ T1] RAX: 9bcc421b8c8b6e00 RBX: ffff8881407a5a9c RCX: ffff8880166d0000
[ 8.068202][ T1] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 8.069406][ T1] RBP: 0000000000000004 R08: ffffffff815800a2 R09: fffffbfff1c396e0
[ 8.070770][ T1] R10: dffffc0000000000 R11: fffffbfff1c396e0 R12: ffffea000502cdc0
[ 8.071923][ T1] R13: ffffea000502cdc8 R14: 1ffffd4000a059b9 R15: 0000000000000000
[ 8.073195][ T1] FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
[ 8.074997][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 8.076208][ T1] CR2: ffff88823ffff000 CR3: 000000000e132000 CR4: 00000000003506f0
[ 8.077586][ T1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 8.079021][ T1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 8.080171][ T1] Call Trace:
[ 8.080710][ T1] <TASK>
[ 8.081192][ T1] ? __warn+0x163/0x4e0
[ 8.082027][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.083285][ T1] ? report_bug+0x2b3/0x500
[ 8.084102][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.084911][ T1] ? handle_bug+0x3e/0x70
[ 8.085560][ T1] ? exc_invalid_op+0x1a/0x50
[ 8.086541][ T1] ? asm_exc_invalid_op+0x1a/0x20
[ 8.087289][ T1] ? __warn_printk+0x292/0x360
[ 8.088095][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.089127][ T1] ? refcount_warn_saturate+0xf9/0x1d0
[ 8.090489][ T1] __free_pages_ok+0xc60/0xd90
[ 8.091183][ T1] make_alloc_exact+0xa3/0xf0
[ 8.092072][ T1] vring_alloc_queue_split+0x20a/0x600
[ 8.093385][ T1] ? __pfx_vring_alloc_queue_split+0x10/0x10
[ 8.094888][ T1] ? vp_find_vqs+0x4c/0x4e0
[ 8.095629][ T1] ? virtscsi_probe+0x3ea/0xf60
[ 8.096312][ T1] ? virtio_dev_probe+0x991/0xaf0
[ 8.097239][ T1] ? really_probe+0x2b8/0xad0
[ 8.098468][ T1] ? driver_probe_device+0x50/0x430
[ 8.099254][ T1] vring_create_virtqueue_split+0xc6/0x310
[ 8.100277][ T1] ? ret_from_fork+0x4b/0x80
[ 8.100955][ T1] ? __pfx_vring_create_virtqueue_split+0x10/0x10
[ 8.101863][ T1] vring_create_virtqueue+0xca/0x110
[ 8.102735][ T1] ? __pfx_vp_notify+0x10/0x10
[ 8.103769][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.104746][ T1] setup_vq+0xe9/0x2d0
[ 8.105350][ T1] ? __pfx_vp_notify+0x10/0x10
[ 8.106064][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.106837][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.107892][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.108758][ T1] vp_setup_vq+0xbf/0x330
[ 8.109837][ T1] ? __pfx_vp_config_changed+0x10/0x10
[ 8.110831][ T1] ? ioread16+0x2f/0x90
[ 8.111461][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.112303][ T1] vp_find_vqs_msix+0x8b2/0xc80
[ 8.113109][ T1] vp_find_vqs+0x4c/0x4e0
[ 8.113869][ T1] virtscsi_init+0x8db/0xd00
[ 8.114601][ T1] ? __pfx_virtscsi_init+0x10/0x10
[ 8.115406][ T1] ? __pfx_default_calc_sets+0x10/0x10
[ 8.116284][ T1] ? scsi_host_alloc+0xa57/0xea0
[ 8.117252][ T1] ? vp_get+0xfd/0x140
[ 8.118053][ T1] virtscsi_probe+0x3ea/0xf60
[ 8.118880][ T1] ? __pfx_virtscsi_probe+0x10/0x10
[ 8.119741][ T1] ? kernfs_add_one+0x156/0x8b0
[ 8.120734][ T1] ? virtio_no_restricted_mem_acc+0x9/0x10
[ 8.121670][ T1] ? virtio_features_ok+0x10c/0x270
[ 8.122793][ T1] virtio_dev_probe+0x991/0xaf0
[ 8.123599][ T1] ? __pfx_virtio_dev_probe+0x10/0x10
[ 8.124434][ T1] really_probe+0x2b8/0xad0
[ 8.125161][ T1] __driver_probe_device+0x1a2/0x390
[ 8.125961][ T1] driver_probe_device+0x50/0x430
[ 8.126905][ T1] __driver_attach+0x45f/0x710
[ 8.127791][ T1] ? __pfx___driver_attach+0x10/0x10
[ 8.128630][ T1] bus_for_each_dev+0x239/0x2b0
[ 8.129617][ T1] ? __pfx___driver_attach+0x10/0x10
[ 8.130766][ T1] ? __pfx_bus_for_each_dev+0x10/0x10
[ 8.131869][ T1] ? do_raw_spin_unlock+0x13c/0x8b0
[ 8.133108][ T1] bus_add_driver+0x347/0x620
[ 8.134579][ T1] driver_register+0x23a/0x320
[ 8.135468][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.136268][ T1] virtio_scsi_init+0x65/0xe0
[ 8.137251][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.138124][ T1] do_one_initcall+0x248/0x880
[ 8.139180][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.140100][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 8.141028][ T1] ? __pfx_do_one_initcall+0x10/0x10
[ 8.141940][ T1] ? __pfx_parse_args+0x10/0x10
[ 8.142812][ T1] ? do_initcalls+0x1c/0x80
[ 8.143461][ T1] ? rcu_is_watching+0x15/0xb0
[ 8.144181][ T1] do_initcall_level+0x157/0x210
[ 8.144944][ T1] do_initcalls+0x3f/0x80
[ 8.145717][ T1] kernel_init_freeable+0x435/0x5d0
[ 8.146491][ T1] ? __pfx_kernel_init_freeable+0x10/0x10
[ 8.147543][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 8.148835][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.149734][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.150860][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.151964][ T1] kernel_init+0x1d/0x2b0
[ 8.152905][ T1] ret_from_fork+0x4b/0x80
[ 8.154244][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.155345][ T1] ret_from_fork_asm+0x1a/0x30
[ 8.156184][ T1] </TASK>
[ 8.156670][ T1] Kernel panic - not syncing: kernel: panic_on_warn set ...
[ 8.157851][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.9.0-rc1-syzkaller-00291-g4090fa373f0e-dirty #0
[ 8.161190][ T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
[ 8.162871][ T1] Call Trace:
[ 8.162871][ T1] <TASK>
[ 8.162871][ T1] dump_stack_lvl+0x241/0x360
[ 8.162871][ T1] ? __pfx_dump_stack_lvl+0x10/0x10
[ 8.162871][ T1] ? __pfx__printk+0x10/0x10
[ 8.162871][ T1] ? _printk+0xd5/0x120
[ 8.162871][ T1] ? vscnprintf+0x5d/0x90
[ 8.162871][ T1] panic+0x349/0x860
[ 8.162871][ T1] ? __warn+0x172/0x4e0
[ 8.162871][ T1] ? __pfx_panic+0x10/0x10
[ 8.162871][ T1] ? show_trace_log_lvl+0x4e6/0x520
[ 8.162871][ T1] ? ret_from_fork_asm+0x1a/0x30
[ 8.162871][ T1] __warn+0x346/0x4e0
[ 8.162871][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.162871][ T1] report_bug+0x2b3/0x500
[ 8.162871][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 8.162871][ T1] handle_bug+0x3e/0x70
[ 8.162871][ T1] exc_invalid_op+0x1a/0x50
[ 8.162871][ T1] asm_exc_invalid_op+0x1a/0x20
[ 8.162871][ T1] RIP: 0010:refcount_warn_saturate+0xfa/0x1d0
[ 8.162871][ T1] Code: b2 00 00 00 e8 97 bb e9 fc 5b 5d c3 cc cc cc cc e8 8b bb e9 fc c6 05 2e c7 e7 0a 01 90 48 c7 c7 e0 33 1f 8c e8 c7 57 ac fc 90 <0f> 0b 90 90 eb d9 e8 6b bb e9 fc c6 05 0b c7 e7 0a 01 90 48 c7 c7
[ 8.162871][ T1] RSP: 0000:ffffc90000066e18 EFLAGS: 00010246
[ 8.162871][ T1] RAX: 9bcc421b8c8b6e00 RBX: ffff8881407a5a9c RCX: ffff8880166d0000
[ 8.162871][ T1] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 8.162871][ T1] RBP: 0000000000000004 R08: ffffffff815800a2 R09: fffffbfff1c396e0
[ 8.162871][ T1] R10: dffffc0000000000 R11: fffffbfff1c396e0 R12: ffffea000502cdc0
[ 8.162871][ T1] R13: ffffea000502cdc8 R14: 1ffffd4000a059b9 R15: 0000000000000000
[ 8.162871][ T1] ? __warn_printk+0x292/0x360
[ 8.162871][ T1] ? refcount_warn_saturate+0xf9/0x1d0
[ 8.162871][ T1] __free_pages_ok+0xc60/0xd90
[ 8.162871][ T1] make_alloc_exact+0xa3/0xf0
[ 8.162871][ T1] vring_alloc_queue_split+0x20a/0x600
[ 8.162871][ T1] ? __pfx_vring_alloc_queue_split+0x10/0x10
[ 8.162871][ T1] ? vp_find_vqs+0x4c/0x4e0
[ 8.162871][ T1] ? virtscsi_probe+0x3ea/0xf60
[ 8.162871][ T1] ? virtio_dev_probe+0x991/0xaf0
[ 8.162871][ T1] ? really_probe+0x2b8/0xad0
[ 8.162871][ T1] ? driver_probe_device+0x50/0x430
[ 8.162871][ T1] vring_create_virtqueue_split+0xc6/0x310
[ 8.162871][ T1] ? ret_from_fork+0x4b/0x80
[ 8.162871][ T1] ? __pfx_vring_create_virtqueue_split+0x10/0x10
[ 8.162871][ T1] vring_create_virtqueue+0xca/0x110
[ 8.162871][ T1] ? __pfx_vp_notify+0x10/0x10
[ 8.162871][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.162871][ T1] setup_vq+0xe9/0x2d0
[ 8.162871][ T1] ? __pfx_vp_notify+0x10/0x10
[ 8.162871][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.212873][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.212873][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.212873][ T1] vp_setup_vq+0xbf/0x330
[ 8.212873][ T1] ? __pfx_vp_config_changed+0x10/0x10
[ 8.212873][ T1] ? ioread16+0x2f/0x90
[ 8.212873][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 8.212873][ T1] vp_find_vqs_msix+0x8b2/0xc80
[ 8.212873][ T1] vp_find_vqs+0x4c/0x4e0
[ 8.212873][ T1] virtscsi_init+0x8db/0xd00
[ 8.212873][ T1] ? __pfx_virtscsi_init+0x10/0x10
[ 8.212873][ T1] ? __pfx_default_calc_sets+0x10/0x10
[ 8.212873][ T1] ? scsi_host_alloc+0xa57/0xea0
[ 8.212873][ T1] ? vp_get+0xfd/0x140
[ 8.212873][ T1] virtscsi_probe+0x3ea/0xf60
[ 8.212873][ T1] ? __pfx_virtscsi_probe+0x10/0x10
[ 8.212873][ T1] ? kernfs_add_one+0x156/0x8b0
[ 8.212873][ T1] ? virtio_no_restricted_mem_acc+0x9/0x10
[ 8.212873][ T1] ? virtio_features_ok+0x10c/0x270
[ 8.212873][ T1] virtio_dev_probe+0x991/0xaf0
[ 8.212873][ T1] ? __pfx_virtio_dev_probe+0x10/0x10
[ 8.212873][ T1] really_probe+0x2b8/0xad0
[ 8.212873][ T1] __driver_probe_device+0x1a2/0x390
[ 8.212873][ T1] driver_probe_device+0x50/0x430
[ 8.212873][ T1] __driver_attach+0x45f/0x710
[ 8.212873][ T1] ? __pfx___driver_attach+0x10/0x10
[ 8.212873][ T1] bus_for_each_dev+0x239/0x2b0
[ 8.212873][ T1] ? __pfx___driver_attach+0x10/0x10
[ 8.212873][ T1] ? __pfx_bus_for_each_dev+0x10/0x10
[ 8.212873][ T1] ? do_raw_spin_unlock+0x13c/0x8b0
[ 8.212873][ T1] bus_add_driver+0x347/0x620
[ 8.212873][ T1] driver_register+0x23a/0x320
[ 8.212873][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.212873][ T1] virtio_scsi_init+0x65/0xe0
[ 8.212873][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.212873][ T1] do_one_initcall+0x248/0x880
[ 8.212873][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 8.212873][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 8.212873][ T1] ? __pfx_do_one_initcall+0x10/0x10
[ 8.212873][ T1] ? __pfx_parse_args+0x10/0x10
[ 8.212873][ T1] ? do_initcalls+0x1c/0x80
[ 8.212873][ T1] ? rcu_is_watching+0x15/0xb0
[ 8.212873][ T1] do_initcall_level+0x157/0x210
[ 8.212873][ T1] do_initcalls+0x3f/0x80
[ 8.212873][ T1] kernel_init_freeable+0x435/0x5d0
[ 8.212873][ T1] ? __pfx_kernel_init_freeable+0x10/0x10
[ 8.212873][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 8.212873][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.212873][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.212873][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.212873][ T1] kernel_init+0x1d/0x2b0
[ 8.212873][ T1] ret_from_fork+0x4b/0x80
[ 8.212873][ T1] ? __pfx_kernel_init+0x10/0x10
[ 8.212873][ T1] ret_from_fork_asm+0x1a/0x30
[ 8.212873][ T1] </TASK>
[ 8.212873][ T1] Kernel Offset: disabled
[ 8.212873][ 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-2/linux/gopath/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/syzkaller/jobs-2/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-2/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-build264214063=/tmp/go-build -gno-record-gcc-switches'

git status (err=<nil>)
HEAD detached at 0ee3535ea
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=0ee3535ea8ff21d50e44372bb1cfd147e299ab5b -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240404-085507'" "-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=0ee3535ea8ff21d50e44372bb1cfd147e299ab5b -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240404-085507'" "-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=0ee3535ea8ff21d50e44372bb1cfd147e299ab5b -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240404-085507'" "-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=\"0ee3535ea8ff21d50e44372bb1cfd147e299ab5b\"


Error text is too large and was truncated, full error text is at:

https://syzkaller.appspot.com/x/error.txt?x=169731ad180000


Tested on:

commit: 4090fa37 af_unix: Replace garbage collection algorithm.
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git
kernel config: https://syzkaller.appspot.com/x/.config?x=be1e18a11ee69044

dashboard link: https://syzkaller.appspot.com/bug?extid=7f7f201cc2668a8fd169
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=15b3cca9180000