bond0 (unregistering): Released all slaves ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 2 PID: 1140 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28 Modules linked in: CPU: 2 PID: 1140 Comm: kworker/u32:10 Not tainted 6.9.0-syzkaller-08995-g0450d2083be6 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Workqueue: netns cleanup_net RIP: 0010:refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28 Code: ff 89 de e8 a8 f5 0e fd 84 db 0f 85 66 ff ff ff e8 1b fb 0e fd c6 05 87 56 4c 0b 01 90 48 c7 c7 60 f6 8e 8b e8 37 7a d1 fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 f8 fa 0e fd 0f b6 1d 62 56 4c 0b 31 RSP: 0018:ffffc900072479d0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81510469 RDX: ffff888020582440 RSI: ffffffff81510476 RDI: 0000000000000001 RBP: ffffe8ffad393ce1 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000003 R12: ffffe8ffad393ce1 R13: 0000000000000000 R14: 0000000000000004 R15: ffffe8ffad393bfd FS: 0000000000000000(0000) GS:ffff88802c200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdb9a1ca440 CR3: 00000000647f8000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_sub_and_test include/linux/refcount.h:275 [inline] __refcount_dec_and_test include/linux/refcount.h:307 [inline] refcount_dec_and_test include/linux/refcount.h:325 [inline] skb_unref include/linux/skbuff.h:1224 [inline] __kfree_skb_reason net/core/skbuff.c:1195 [inline] kfree_skb_reason+0x1e8/0x210 net/core/skbuff.c:1222 kfree_skb include/linux/skbuff.h:1257 [inline] flush_gro_hash net/core/dev.c:6682 [inline] __netif_napi_del net/core/dev.c:6697 [inline] __netif_napi_del+0x311/0x570 net/core/dev.c:6688 gro_cells_destroy net/core/gro_cells.c:117 [inline] gro_cells_destroy+0x10a/0x4d0 net/core/gro_cells.c:106 ip_tunnel_dev_free+0x19/0x60 net/ipv4/ip_tunnel.c:1100 netdev_run_todo+0x775/0x1250 net/core/dev.c:10692 cleanup_net+0x591/0xbf0 net/core/net_namespace.c:636 process_one_work+0x958/0x1ad0 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244