=============================
WARNING: suspicious RCU usage
4.16.0-rc2+ #246 Not tainted
-----------------------------
./include/net/inet_sock.h:136 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-executor0/24191:
 #0:  (sk_lock-AF_INET6){+.+.}, at: [<000000007814c553>] lock_sock include/net/sock.h:1464 [inline]
 #0:  (sk_lock-AF_INET6){+.+.}, at: [<000000007814c553>] inet_csk_accept+0xac/0xde0 net/ipv4/inet_connection_sock.c:438

stack backtrace:
CPU: 0 PID: 24191 Comm: syz-executor0 Not tainted 4.16.0-rc2+ #246
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+0x194/0x24d lib/dump_stack.c:53
 lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4592
 ireq_opt_deref include/net/inet_sock.h:135 [inline]
 inet_csk_route_req+0x824/0xca0 net/ipv4/inet_connection_sock.c:543
 dccp_v4_send_response+0xa7/0x650 net/dccp/ipv4.c:485
 dccp_v4_conn_request+0x9ee/0x11b0 net/dccp/ipv4.c:633
 dccp_v6_conn_request+0xd30/0x1410 net/dccp/ipv6.c:317
 dccp_rcv_state_process+0x574/0x1620 net/dccp/input.c:612
 dccp_v4_do_rcv+0xf1/0x160 net/dccp/ipv4.c:682
 dccp_v6_do_rcv+0x86a/0xa70 net/dccp/ipv6.c:578
 sk_backlog_rcv include/net/sock.h:909 [inline]
 __release_sock+0x124/0x360 net/core/sock.c:2275
 release_sock+0xa4/0x2a0 net/core/sock.c:2790
 inet_csk_wait_for_connect net/ipv4/inet_connection_sock.c:405 [inline]
 inet_csk_accept+0x48c/0xde0 net/ipv4/inet_connection_sock.c:456
 inet_accept+0x12c/0x930 net/ipv4/af_inet.c:699
 SYSC_accept4+0x386/0x840 net/socket.c:1571
 SyS_accept4+0x2c/0x40 net/socket.c:1522
 do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x453d69
RSP: 002b:00007f06e977dc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000120
RAX: ffffffffffffffda RBX: 00007f06e977e6d4 RCX: 0000000000453d69
RDX: 0000000020752ffc RSI: 0000000020975000 RDI: 0000000000000013
RBP: 000000000072c010 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000000b R14: 00000000006f01a8 R15: 0000000000000002

=============================
WARNING: suspicious RCU usage
4.16.0-rc2+ #246 Not tainted
-----------------------------
./include/net/inet_sock.h:136 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-executor0/24191:
 #0:  (sk_lock-AF_INET6){+.+.}, at: [<000000007814c553>] lock_sock include/net/sock.h:1464 [inline]
 #0:  (sk_lock-AF_INET6){+.+.}, at: [<000000007814c553>] inet_csk_accept+0xac/0xde0 net/ipv4/inet_connection_sock.c:438

stack backtrace:
CPU: 0 PID: 24191 Comm: syz-executor0 Not tainted 4.16.0-rc2+ #246
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+0x194/0x24d lib/dump_stack.c:53
 lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4592
 ireq_opt_deref include/net/inet_sock.h:135 [inline]
 dccp_v4_send_response+0x4b6/0x650 net/dccp/ipv4.c:496
 dccp_v4_conn_request+0x9ee/0x11b0 net/dccp/ipv4.c:633
 dccp_v6_conn_request+0xd30/0x1410 net/dccp/ipv6.c:317
 dccp_rcv_state_process+0x574/0x1620 net/dccp/input.c:612
 dccp_v4_do_rcv+0xf1/0x160 net/dccp/ipv4.c:682
 dccp_v6_do_rcv+0x86a/0xa70 net/dccp/ipv6.c:578
 sk_backlog_rcv include/net/sock.h:909 [inline]
 __release_sock+0x124/0x360 net/core/sock.c:2275
 release_sock+0xa4/0x2a0 net/core/sock.c:2790
 inet_csk_wait_for_connect net/ipv4/inet_connection_sock.c:405 [inline]
 inet_csk_accept+0x48c/0xde0 net/ipv4/inet_connection_sock.c:456
 inet_accept+0x12c/0x930 net/ipv4/af_inet.c:699
 SYSC_accept4+0x386/0x840 net/socket.c:1571
 SyS_accept4+0x2c/0x40 net/socket.c:1522
 do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x453d69
RSP: 002b:00007f06e977dc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000120
RAX: ffffffffffffffda RBX: 00007f06e977e6d4 RCX: 0000000000453d69
RDX: 0000000020752ffc RSI: 0000000020975000 RDI: 0000000000000013
RBP: 000000000072c010 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000000b R14: 00000000006f01a8 R15: 0000000000000002
dccp_close: ABORT with 65423 bytes unread
netlink: 8 bytes leftover after parsing attributes in process `syz-executor3'.
netlink: 8 bytes leftover after parsing attributes in process `syz-executor3'.