============================= WARNING: suspicious RCU usage 5.11.0-rc2-syzkaller #0 Not tainted ----------------------------- include/net/sock.h:1975 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by syz-executor.2/10193: #0: ffff88810b4b8120 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1594 [inline] #0: ffff88810b4b8120 (sk_lock-AF_INET6){+.+.}-{0:0}, at: inet_shutdown+0x32/0x100 net/ipv4/af_inet.c:871 stack backtrace: CPU: 0 PID: 10193 Comm: syz-executor.2 Not tainted 5.11.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x77/0x97 lib/dump_stack.c:120 __sk_dst_set include/net/sock.h:1974 [inline] __sk_dst_reset include/net/sock.h:1994 [inline] tcp_disconnect+0x66c/0x690 net/ipv4/tcp.c:2963 mptcp_disconnect+0x2e/0x40 net/mptcp/protocol.c:2650 inet_shutdown+0xa1/0x100 net/ipv4/af_inet.c:901 __sys_shutdown+0x37/0x70 net/socket.c:2196 __do_sys_shutdown net/socket.c:2204 [inline] __se_sys_shutdown net/socket.c:2202 [inline] __x64_sys_shutdown+0xd/0x10 net/socket.c:2202 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e219 Code: 0d b4 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 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0e37bddc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000030 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 000000000045e219 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000119bfb8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffd49a0564f R14: 00007f0e37bde9c0 R15: 000000000119bf8c