============================= WARNING: suspicious RCU usage 4.14.281-syzkaller #0 Not tainted ----------------------------- net/netfilter/nf_queue.c:244 suspicious rcu_dereference_check() usage! netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'. other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by ksoftirqd/0/7: #0: (rcu_callback){....}, at: [] __rcu_reclaim kernel/rcu/rcu.h:185 [inline] #0: (rcu_callback){....}, at: [] rcu_do_batch kernel/rcu/tree.c:2699 [inline] #0: (rcu_callback){....}, at: [] invoke_rcu_callbacks kernel/rcu/tree.c:2962 [inline] #0: (rcu_callback){....}, at: [] __rcu_process_callbacks kernel/rcu/tree.c:2929 [inline] #0: (rcu_callback){....}, at: [] rcu_process_callbacks+0x84e/0x1180 kernel/rcu/tree.c:2946 #1: (&(&inst->lock)->rlock){+.-.}, at: [] spin_lock_bh include/linux/spinlock.h:322 [inline] #1: (&(&inst->lock)->rlock){+.-.}, at: [] nfqnl_flush+0x2f/0x2a0 net/netfilter/nfnetlink_queue.c:232 ip_tables: iptables: counters copy to user failed while replacing table stack backtrace: CPU: 0 PID: 7 Comm: ksoftirqd/0 Not tainted 4.14.281-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 nf_reinject+0x56e/0x700 net/netfilter/nf_queue.c:244 nfqnl_flush+0x1ab/0x2a0 net/netfilter/nfnetlink_queue.c:237 instance_destroy_rcu+0x19/0x30 net/netfilter/nfnetlink_queue.c:171 netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'. __rcu_reclaim kernel/rcu/rcu.h:195 [inline] rcu_do_batch kernel/rcu/tree.c:2699 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2962 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2929 [inline] rcu_process_callbacks+0x780/0x1180 kernel/rcu/tree.c:2946 __do_softirq+0x24d/0x9ff kernel/softirq.c:288 run_ksoftirqd+0x50/0x1a0 kernel/softirq.c:670 smpboot_thread_fn+0x5c1/0x920 kernel/smpboot.c:164 ip_tables: iptables: counters copy to user failed while replacing table kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 netlink: 12 bytes leftover after parsing attributes in process `syz-executor.3'. ip_tables: iptables: counters copy to user failed while replacing table netlink: 12 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'. ip_tables: iptables: counters copy to user failed while replacing table kvm: vcpu 0: requested 128 ns lapic timer period limited to 500000 ns ip_tables: iptables: counters copy to user failed while replacing table kvm: vcpu 0: requested 128 ns lapic timer period limited to 500000 ns netlink: 12 bytes leftover after parsing attributes in process `syz-executor.3'. ip_tables: iptables: counters copy to user failed while replacing table kvm: vcpu 0: requested 128 ns lapic timer period limited to 500000 ns kvm: vcpu 0: requested 128 ns lapic timer period limited to 500000 ns kvm: vcpu 0: requested 128 ns lapic timer period limited to 500000 ns kvm: vcpu 0: requested 128 ns lapic timer period limited to 500000 ns netlink: 176 bytes leftover after parsing attributes in process `syz-executor.5'. device ip6gretap0 entered promiscuous mode netlink: 176 bytes leftover after parsing attributes in process `syz-executor.5'. Zero length message leads to an empty skb netlink: 176 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 176 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 176 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 176 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 176 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 176 bytes leftover after parsing attributes in process `syz-executor.5'. rdma_op ffff88809bec6658 conn xmit_rdma (null) affs: No valid root block on device loop1 affs: No valid root block on device loop1 affs: No valid root block on device loop1 affs: No valid root block on device loop1 tmpfs: Bad value 'local:' for mount option 'mpol'