============================= WARNING: suspicious RCU usage syzkaller #0 Not tainted ----------------------------- net/xfrm/xfrm_user.c:1630 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.2.45/6036: #0: ffff88804fef1c50 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{4:4}, at: xfrm_netlink_rcv+0x62/0x90 net/xfrm/xfrm_user.c:3928 stack backtrace: CPU: 0 UID: 0 PID: 6036 Comm: syz.2.45 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 lockdep_rcu_suspicious.cold+0x4f/0xb1 kernel/locking/lockdep.c:6876 xfrm_nlmsg_multicast net/xfrm/xfrm_user.c:1630 [inline] xfrm_send_migrate_state net/xfrm/xfrm_user.c:3340 [inline] xfrm_do_migrate_state+0x2463/0x2f10 net/xfrm/xfrm_user.c:3507 xfrm_user_rcv_msg+0x411/0xd00 net/xfrm/xfrm_user.c:3907 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556 xfrm_netlink_rcv+0x71/0x90 net/xfrm/xfrm_user.c:3929 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2684 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2738 __sys_sendmsg+0x160/0x210 net/socket.c:2770 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf6fdefec Code: Unable to access opcode bytes at 0xf6fdefc2. RSP: 002b:00000000f53cd50c EFLAGS: 00000292 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080000500 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000