./strace-static-x86_64 -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f ./syz-executor4008601033 <...> Warning: Permanently added '10.128.0.6' (ECDSA) to the list of known hosts. execve("./syz-executor4008601033", ["./syz-executor4008601033"], 0x7ffd7463b230 /* 10 vars */) = 0 brk(NULL) = 0x555555dd5000 brk(0x555555dd5c40) = 0x555555dd5c40 arch_prctl(ARCH_SET_FS, 0x555555dd5300) = 0 uname({sysname="Linux", nodename="syzkaller", ...}) = 0 readlink("/proc/self/exe", "/root/syz-executor4008601033", 4096) = 28 brk(0x555555df6c40) = 0x555555df6c40 brk(0x555555df7000) = 0x555555df7000 mprotect(0x7f7ffcdf6000, 16384, PROT_READ) = 0 mmap(0x1ffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x1ffff000 mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000 mmap(0x21000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x21000000 socket(AF_INET6, SOCK_DGRAM, IPPROTO_IP) = 3 setsockopt(3, SOL_SOCKET, SO_REUSEPORT, [6], 4) = 0 bind(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::ffff:255.255.255.255", &sin6_addr), sin6_scope_id=0}, 28) = 0 exit_group(0) = ? syzkaller login: [ 49.951273][ T3608] [ 49.953730][ T3608] ============================= [ 49.958561][ T3608] WARNING: suspicious RCU usage [ 49.963447][ T3608] 6.0.0-rc1-next-20220818-syzkaller #0 Not tainted [ 49.969943][ T3608] ----------------------------- [ 49.974800][ T3608] include/net/sock.h:592 suspicious rcu_dereference_check() usage! [ 49.982717][ T3608] [ 49.982717][ T3608] other info that might help us debug this: [ 49.982717][ T3608] [ 49.993142][ T3608] [ 49.993142][ T3608] rcu_scheduler_active = 2, debug_locks = 1 [ 50.001248][ T3608] 4 locks held by syz-executor400/3608: [ 50.006798][ T3608] #0: ffff88801ebdac10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release+0x86/0x280 [ 50.017448][ T3608] #1: ffffc90001501388 (&table->hash[i].lock){+...}-{2:2}, at: udp_lib_unhash+0x1d5/0x730 [ 50.027514][ T3608] #2: ffffffff8d7beb78 (reuseport_lock){+...}-{2:2}, at: reuseport_detach_sock+0x22/0x4a0 [ 50.037587][ T3608] #3: ffff88807c8293b8 (clock-AF_INET6){++..}-{2:2}, at: bpf_sk_reuseport_detach+0x26/0x190 [ 50.047860][ T3608] [ 50.047860][ T3608] stack backtrace: [ 50.053850][ T3608] CPU: 1 PID: 3608 Comm: syz-executor400 Not tainted 6.0.0-rc1-next-20220818-syzkaller #0 [ 50.063768][ T3608] syz-executor400[3608] cmdline: a [ 50.069588][ T3608] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 [ 50.079664][ T3608] Call Trace: [ 50.082988][ T3608] [ 50.085937][ T3608] dump_stack_lvl+0xcd/0x134 [ 50.091861][ T3608] bpf_sk_reuseport_detach+0x156/0x190 [ 50.097386][ T3608] reuseport_detach_sock+0x8c/0x4a0 [ 50.102627][ T3608] udp_lib_unhash+0x210/0x730 [ 50.107343][ T3608] ? udpv6_pre_connect+0x180/0x180 [ 50.112480][ T3608] sk_common_release+0xba/0x390 [ 50.117386][ T3608] inet_release+0x12e/0x270 [ 50.121923][ T3608] inet6_release+0x4c/0x70 [ 50.126372][ T3608] __sock_release+0xcd/0x280 [ 50.130986][ T3608] sock_close+0x18/0x20 [ 50.135160][ T3608] __fput+0x27c/0xa90 [ 50.139167][ T3608] ? __sock_release+0x280/0x280 [ 50.144052][ T3608] task_work_run+0xdd/0x1a0 [ 50.148587][ T3608] do_exit+0xc39/0x2b60 [ 50.152762][ T3608] ? lock_downgrade+0x6e0/0x6e0 [ 50.157625][ T3608] ? do_raw_spin_lock+0x120/0x2a0 [ 50.162670][ T3608] ? mm_update_next_owner+0x7a0/0x7a0 [ 50.168049][ T3608] ? rwlock_bug.part.0+0x90/0x90 [ 50.173000][ T3608] ? _raw_spin_unlock_irq+0x1f/0x40 [ 50.178205][ T3608] ? _raw_spin_unlock_irq+0x1f/0x40 [ 50.183415][ T3608] do_group_exit+0xd0/0x2a0 [ 50.187929][ T3608] __x64_sys_exit_group+0x3a/0x50 [ 50.192961][ T3608] do_syscall_64+0x35/0xb0 [ 50.197390][ T3608] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 50.203319][ T3608] RIP: 0033:0x7f7ffcd88699 [ 50.207750][ T3608] Code: Unable to access opcode bytes at RIP 0x7f7ffcd8866f. [ 50.215110][ T3608] RSP: 002b:00007ffceb32ef08 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 50.223529][ T3608] RAX: ffffffffffffffda RBX: 00007f7ffcdfc270 RCX: 00007f7ffcd88699 [ 50.231502][ T3608] RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 [ 50.239474][ T3608] RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000000000 +++ exited with 0 +++ [ 50.247554][ T3608] R10: 0000000000000004 R11: 0000000000