WARNING: refcount bug in __netif_napi

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	WARNING: refcount bug in __netif_napi_del (3) net	13				18	387d	417d	0/29	auto-obsoleted due to no activity on 2024/09/02 17:25
upstream	WARNING: refcount bug in __netif_napi_del (2) net	13				3	1221d	1256d	0/29	auto-closed as invalid on 2022/06/11 05:51

------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 8 at lib/refcount.c:28 refcount_warn_saturate+0x1d1/0x1e0 lib/refcount.c:28 Modules linked in: CPU: 1 PID: 8 Comm: kworker/u4:0 Not tainted 5.15.0-rc6-syzkaller #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 9c b2 e3 fd e9 8a fe ff ff e8 72 5a 9c fd 48 c7 c7 a0 ee e3 89 c6 05 19 8a 7f 09 01 e8 db 6e 19 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:ffffc90000cd7958 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888011ebd580 RSI: ffffffff815e8da8 RDI: fffff5200019af1d RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815e2b4e R11: 0000000000000000 R12: ffffe8ffffc9621d R13: dffffc0000000000 R14: 0000000000000007 R15: ffffe8ffffc96141 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055ddc90bb160 CR3: 00000000733c8000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 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:1068 [inline] skb_unref include/linux/skbuff.h:1062 [inline] kfree_skb+0x326/0x3f0 net/core/skbuff.c:770 flush_gro_hash net/core/dev.c:6954 [inline] __netif_napi_del.part.0+0x2c6/0x520 net/core/dev.c:6969 __netif_napi_del+0x3c/0x50 net/core/dev.c:6962 gro_cells_destroy net/core/gro_cells.c:102 [inline] gro_cells_destroy+0x115/0x360 net/core/gro_cells.c:92 ip6_dev_free+0x15/0x60 net/ipv6/ip6_tunnel.c:248 netdev_run_todo+0x6b4/0xa80 net/core/dev.c:10600 ip6_tnl_exit_batch_net+0x5fa/0x890 net/ipv6/ip6_tunnel.c:2312 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:171 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:591 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295