./strace-static-x86_64 -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f ./syz-executor1210296805 <...> Warning: Permanently added '10.128.0.27' (ECDSA) to the list of known hosts. execve("./syz-executor1210296805", ["./syz-executor1210296805"], 0x7ffdaf4f19e0 /* 10 vars */) = 0 brk(NULL) = 0x555556ecf000 brk(0x555556ecfc40) = 0x555556ecfc40 arch_prctl(ARCH_SET_FS, 0x555556ecf300) = 0 uname({sysname="Linux", nodename="syzkaller", ...}) = 0 readlink("/proc/self/exe", "/root/syz-executor1210296805", 4096) = 28 brk(0x555556ef0c40) = 0x555556ef0c40 brk(0x555556ef1000) = 0x555556ef1000 mprotect(0x7f9aaf851000, 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_INET, SOCK_DCCP, IPPROTO_IP) = 3 setsockopt(3, SOL_SOCKET, SO_REUSEPORT, [30272], 4) = 0 setsockopt(3, SOL_SOCKET, SO_ATTACH_REUSEPORT_CBPF, {len=1, filter=0x20f07000}, 16) = 0 exit_group(0) = ? syzkaller login: [ 49.877650][ T3609] [ 49.880089][ T3609] ============================= [ 49.884952][ T3609] WARNING: suspicious RCU usage [ 49.889784][ T3609] 6.0.0-rc1-next-20220818-syzkaller #0 Not tainted [ 49.896296][ T3609] ----------------------------- [ 49.901125][ T3609] include/net/sock.h:592 suspicious rcu_dereference_check() usage! [ 49.909041][ T3609] [ 49.909041][ T3609] other info that might help us debug this: [ 49.909041][ T3609] [ 49.919309][ T3609] [ 49.919309][ T3609] rcu_scheduler_active = 2, debug_locks = 1 [ 49.927427][ T3609] 3 locks held by syz-executor121/3609: [ 49.933012][ T3609] #0: ffff888071078e10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release+0x86/0x280 [ 49.943697][ T3609] #1: ffffffff8d7beb78 (reuseport_lock){+...}-{2:2}, at: reuseport_detach_sock+0x22/0x4a0 [ 49.953825][ T3609] #2: ffff8880214083b8 (clock-AF_INET){++..}-{2:2}, at: bpf_sk_reuseport_detach+0x26/0x190 [ 49.963989][ T3609] [ 49.963989][ T3609] stack backtrace: [ 49.969903][ T3609] CPU: 1 PID: 3609 Comm: syz-executor121 Not tainted 6.0.0-rc1-next-20220818-syzkaller #0 [ 49.979797][ T3609] syz-executor121[3609] cmdline: a [ 49.985603][ T3609] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 [ 49.995664][ T3609] Call Trace: [ 49.998954][ T3609] [ 50.001892][ T3609] dump_stack_lvl+0xcd/0x134 [ 50.006525][ T3609] bpf_sk_reuseport_detach+0x156/0x190 [ 50.012012][ T3609] reuseport_detach_sock+0x8c/0x4a0 [ 50.017227][ T3609] ? mark_held_locks+0x9f/0xe0 [ 50.022023][ T3609] __sk_free+0x130/0x460 [ 50.026275][ T3609] sk_free+0x78/0xa0 [ 50.030197][ T3609] dccp_close+0xa0c/0xd50 [ 50.034545][ T3609] ? dccp_recvmsg+0x9d0/0x9d0 [ 50.039250][ T3609] ? down_write+0xde/0x150 [ 50.043682][ T3609] ? ip_mc_drop_socket+0x16/0x260 [ 50.048716][ T3609] ? locks_remove_file+0x2f7/0x570 [ 50.053850][ T3609] inet_release+0x12e/0x270 [ 50.058380][ T3609] __sock_release+0xcd/0x280 [ 50.062997][ T3609] sock_close+0x18/0x20 [ 50.067168][ T3609] __fput+0x27c/0xa90 [ 50.071165][ T3609] ? __sock_release+0x280/0x280 [ 50.076034][ T3609] task_work_run+0xdd/0x1a0 [ 50.080549][ T3609] do_exit+0xc39/0x2b60 [ 50.084715][ T3609] ? lock_downgrade+0x6e0/0x6e0 [ 50.089588][ T3609] ? do_raw_spin_lock+0x120/0x2a0 [ 50.094623][ T3609] ? mm_update_next_owner+0x7a0/0x7a0 [ 50.100005][ T3609] ? rwlock_bug.part.0+0x90/0x90 [ 50.104954][ T3609] ? _raw_spin_unlock_irq+0x1f/0x40 [ 50.110182][ T3609] ? _raw_spin_unlock_irq+0x1f/0x40 [ 50.115406][ T3609] do_group_exit+0xd0/0x2a0 [ 50.119932][ T3609] __x64_sys_exit_group+0x3a/0x50 [ 50.124968][ T3609] do_syscall_64+0x35/0xb0 [ 50.129405][ T3609] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 50.135327][ T3609] RIP: 0033:0x7f9aaf7e3699 [ 50.139769][ T3609] Code: Unable to access opcode bytes at RIP 0x7f9aaf7e366f. [ 50.147145][ T3609] RSP: 002b:00007ffc5cf2b068 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 50.155570][ T3609] RAX: ffffffffffffffda RBX: 00007f9aaf857270 RCX: 00007f9aaf7e3699 [ 50.163546][ T3609] RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 +++ exited with 0 +++ [ 50.171520][ T3609] RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 00000000000000