./strace-static-x86_64 -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f ./syz-executor673679730 <...> Warning: Permanently added '10.128.1.19' (ECDSA) to the list of known hosts. execve("./syz-executor673679730", ["./syz-executor673679730"], 0x7ffefba2e560 /* 10 vars */) = 0 brk(NULL) = 0x5555555ed000 brk(0x5555555edc40) = 0x5555555edc40 arch_prctl(ARCH_SET_FS, 0x5555555ed300) = 0 uname({sysname="Linux", nodename="syzkaller", ...}) = 0 readlink("/proc/self/exe", "/root/syz-executor673679730", 4096) = 27 brk(0x55555560ec40) = 0x55555560ec40 brk(0x55555560f000) = 0x55555560f000 mprotect(0x7ff4b10e4000, 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, [65540], 4) = 0 bind(3, {sa_family=AF_INET6, sin6_port=htons(3618), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::", &sin6_addr), sin6_scope_id=0}, 28) = 0 exit_group(0) = ? syzkaller login: [ 50.869759][ T3609] [ 50.872205][ T3609] ============================= [ 50.877081][ T3609] WARNING: suspicious RCU usage [ 50.881932][ T3609] 6.0.0-rc1-next-20220818-syzkaller #0 Not tainted [ 50.888459][ T3609] ----------------------------- [ 50.893324][ T3609] include/net/sock.h:592 suspicious rcu_dereference_check() usage! [ 50.901245][ T3609] [ 50.901245][ T3609] other info that might help us debug this: [ 50.901245][ T3609] [ 50.911500][ T3609] [ 50.911500][ T3609] rcu_scheduler_active = 2, debug_locks = 1 [ 50.919645][ T3609] 4 locks held by syz-executor673/3609: [ 50.925206][ T3609] #0: ffff8880738c1410 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release+0x86/0x280 [ 50.935793][ T3609] #1: ffffc900014fd2d8 (&table->hash[i].lock){+...}-{2:2}, at: udp_lib_unhash+0x1d5/0x730 [ 50.945873][ T3609] #2: ffffffff8d7beb78 (reuseport_lock){+...}-{2:2}, at: reuseport_detach_sock+0x22/0x4a0 [ 50.955945][ T3609] #3: ffff88814b41b3b8 (clock-AF_INET6){++..}-{2:2}, at: bpf_sk_reuseport_detach+0x26/0x190 [ 50.966213][ T3609] [ 50.966213][ T3609] stack backtrace: [ 50.972150][ T3609] CPU: 1 PID: 3609 Comm: syz-executor673 Not tainted 6.0.0-rc1-next-20220818-syzkaller #0 [ 50.982050][ T3609] syz-executor673[3609] cmdline: a [ 50.987854][ T3609] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 [ 50.997912][ T3609] Call Trace: [ 51.001190][ T3609] [ 51.004123][ T3609] dump_stack_lvl+0xcd/0x134 [ 51.008739][ T3609] bpf_sk_reuseport_detach+0x156/0x190 [ 51.014220][ T3609] reuseport_detach_sock+0x8c/0x4a0 [ 51.019440][ T3609] udp_lib_unhash+0x210/0x730 [ 51.024129][ T3609] ? udpv6_pre_connect+0x180/0x180 [ 51.029245][ T3609] sk_common_release+0xba/0x390 [ 51.034107][ T3609] inet_release+0x12e/0x270 [ 51.038632][ T3609] inet6_release+0x4c/0x70 [ 51.043059][ T3609] __sock_release+0xcd/0x280 [ 51.047671][ T3609] sock_close+0x18/0x20 [ 51.051833][ T3609] __fput+0x27c/0xa90 [ 51.055835][ T3609] ? __sock_release+0x280/0x280 [ 51.060706][ T3609] task_work_run+0xdd/0x1a0 [ 51.065223][ T3609] do_exit+0xc39/0x2b60 [ 51.069390][ T3609] ? lock_downgrade+0x6e0/0x6e0 [ 51.074248][ T3609] ? do_raw_spin_lock+0x120/0x2a0 [ 51.079285][ T3609] ? mm_update_next_owner+0x7a0/0x7a0 [ 51.084663][ T3609] ? rwlock_bug.part.0+0x90/0x90 [ 51.089617][ T3609] ? _raw_spin_unlock_irq+0x1f/0x40 [ 51.094825][ T3609] ? _raw_spin_unlock_irq+0x1f/0x40 [ 51.100040][ T3609] do_group_exit+0xd0/0x2a0 [ 51.104553][ T3609] __x64_sys_exit_group+0x3a/0x50 [ 51.109584][ T3609] do_syscall_64+0x35/0xb0 [ 51.114012][ T3609] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 51.119913][ T3609] RIP: 0033:0x7ff4b1076679 [ 51.124333][ T3609] Code: Unable to access opcode bytes at RIP 0x7ff4b107664f. [ 51.131707][ T3609] RSP: 002b:00007ffcb296e708 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 51.140210][ T3609] RAX: ffffffffffffffda RBX: 00007ff4b10ea270 RCX: 00007ff4b1076679 [ 51.148185][ T3609] RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 [ 51.156156][ T3609] RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000000000 +++ exited with 0 +++ [ 51.164129][ T3609] R10: 0000000000000004 R11: 0000000000000246 R12: 00007ff4b