WARNING: CPU: 0 PID: 7194 at lib/refcount.c:28 refcount_warn_saturate+0x1d1/0x1e0 lib/refcount.c:28 Modules linked in: CPU: 1 PID: 7194 Comm: kworker/u4:10 Not tainted 5.17.0-rc6-syzkaller-01984-gd3b351f65bf4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:refcount_warn_saturate+0x1d1/0x1e0 lib/refcount.c:28 Code: e9 db fe ff ff 48 89 df e8 4c 0f e1 fd e9 8a fe ff ff e8 62 32 99 fd 48 c7 c7 80 39 06 8a c6 05 66 8a a0 09 01 e8 26 e2 2c 05 <0f> 0b e9 af fe ff ff 0f 1f 84 00 00 00 00 00 41 56 41 55 41 54 55 RSP: 0018:ffffc90006087968 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888079ffba00 RSI: ffffffff815fe2c8 RDI: fffff52000c10f1f RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815f895e R11: 0000000000000000 R12: ffffe8ffffd6f655 R13: 0000000000000000 R14: 0000000000000007 R15: ffffe8ffffd6f579 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f28429f9718 CR3: 000000004f2cb000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] skb_unref include/linux/skbuff.h:1204 [inline] skb_unref include/linux/skbuff.h:1198 [inline] kfree_skb_reason+0xf6/0x110 net/core/skbuff.c:772 kfree_skb include/linux/skbuff.h:1218 [inline] flush_gro_hash net/core/dev.c:6362 [inline] __netif_napi_del.part.0+0x2ca/0x530 net/core/dev.c:6377 __netif_napi_del+0x3c/0x50 net/core/dev.c:6370 gro_cells_destroy net/core/gro_cells.c:117 [inline] gro_cells_destroy+0x115/0x430 net/core/gro_cells.c:106 ip6_dev_free+0x15/0x60 net/ipv6/ip6_tunnel.c:248 netdev_run_todo+0x68b/0x10b0 net/core/dev.c:10244 ip6_tnl_exit_batch_net+0x5fa/0x890 net/ipv6/ip6_tunnel.c:2320 ops_exit_list+0x125/0x170 net/core/net_namespace.c:167 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:594 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295