============================= WARNING: suspicious RCU usage 5.2.0-rc5+ #1 Not tainted ----------------------------- net/ipv4/route.c:2875 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-executor.1/7594: #0: 0000000025de6ea8 (rtnl_mutex){+.+.}, at: netlink_dump+0xcc/0x10c0 net/netlink/af_netlink.c:2199 stack backtrace: CPU: 1 PID: 7594 Comm: syz-executor.1 Not tainted 5.2.0-rc5+ #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x113/0x167 lib/dump_stack.c:113 lockdep_rcu_suspicious+0x14a/0x153 kernel/locking/lockdep.c:5250 fib_dump_info_fnhe+0x70a/0xbc0 net/ipv4/route.c:2875 fn_trie_dump_leaf net/ipv4/fib_trie.c:2141 [inline] fib_table_dump+0x683/0xca0 net/ipv4/fib_trie.c:2175 inet_dump_fib+0x343/0x9c0 net/ipv4/fib_frontend.c:1004 rtnl_dump_all+0x1ca/0x3a0 net/core/rtnetlink.c:3445 netlink_dump+0x49e/0x10c0 net/netlink/af_netlink.c:2244 __netlink_dump_start+0x52b/0x810 net/netlink/af_netlink.c:2352 netlink_dump_start include/linux/netlink.h:226 [inline] rtnetlink_rcv_msg+0x57a/0x8f0 net/core/rtnetlink.c:5182 netlink_rcv_skb+0x13c/0x380 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:5237 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x43f/0x630 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x765/0xc50 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0xf0 net/socket.c:665 sock_write_iter+0x1e9/0x3d0 net/socket.c:994 call_write_iter include/linux/fs.h:1872 [inline] new_sync_write+0x3fd/0x7e0 fs/read_write.c:483 __vfs_write+0x94/0x110 fs/read_write.c:496 vfs_write+0x150/0x4e0 fs/read_write.c:558 ksys_write+0x105/0x220 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x6e/0xb0 fs/read_write.c:620 do_syscall_64+0xd0/0x530 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459519 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffa05f45c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459519 RDX: 000000000000001c RSI: 0000000020000000 RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffa05f466d4 R13: 00000000004c58be R14: 00000000004df8c0 R15: 00000000ffffffff