============================= WARNING: suspicious RCU usage 5.15.0-rc2-next-20210920-syzkaller #0 Not tainted ----------------------------- net/xfrm/xfrm_user.c:1157 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by syz-executor917/6560: #0: ffffffff8d0d4818 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{3:3}, at: xfrm_netlink_rcv+0x5c/0x90 net/xfrm/xfrm_user.c:2928 stack backtrace: CPU: 0 PID: 6560 Comm: syz-executor917 Not tainted 5.15.0-rc2-next-20210920-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 xfrm_nlmsg_multicast net/xfrm/xfrm_user.c:1157 [inline] xfrm_notify_userpolicy net/xfrm/xfrm_user.c:1991 [inline] xfrm_set_default+0x789/0x8b0 net/xfrm/xfrm_user.c:2017 xfrm_user_rcv_msg+0x430/0xa20 net/xfrm/xfrm_user.c:2907 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504 xfrm_netlink_rcv+0x6b/0x90 net/xfrm/xfrm_user.c:2929 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2409 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2492 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fe115dcd079 Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffedbf3ee68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe115dcd079 RDX: 0000000000000000 RSI: 0000000020000280 RDI: 0000000000000003 RBP: 00007fe115d91060 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe115d910f0 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 unsupported nlmsg_t