./strace-static-x86_64 -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f ./syz-executor2903297926 <...> DUID 00:04:cd:7d:74:7d:04:96:3f:c0:f2:1a:da:5a:49:b1:9f:fb forked to background, child pid 3187 [ 26.937114][ T3188] 8021q: adding VLAN 0 to HW filter on device bond0 [ 26.946687][ T3188] eql: remember to turn off Van-Jacobson compression on your slave devices Starting sshd: OK syzkaller Warning: Permanently added '10.128.0.218' (ECDSA) to the list of known hosts. execve("./syz-executor2903297926", ["./syz-executor2903297926"], 0x7ffd498d2860 /* 10 vars */) = 0 brk(NULL) = 0x5555559a7000 brk(0x5555559a7c40) = 0x5555559a7c40 arch_prctl(ARCH_SET_FS, 0x5555559a7300) = 0 uname({sysname="Linux", nodename="syzkaller", ...}) = 0 readlink("/proc/self/exe", "/root/syz-executor2903297926", 4096) = 28 brk(0x5555559c8c40) = 0x5555559c8c40 brk(0x5555559c9000) = 0x5555559c9000 mprotect(0x7f8e61fe4000, 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|SOCK_CLOEXEC, IPPROTO_IP) = 3 setsockopt(3, SOL_SOCKET, SO_REUSEPORT, [11], 4) = 0 bind(3, {sa_family=AF_INET6, sin6_port=htons(20000), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::", &sin6_addr), sin6_scope_id=0}, 28) = 0 exit_group(0) = ? syzkaller login: [ 50.058163][ T3608] [ 50.060638][ T3608] ============================= [ 50.065473][ T3608] WARNING: suspicious RCU usage [ 50.070345][ T3608] 6.0.0-rc1-next-20220818-syzkaller #0 Not tainted [ 50.076852][ T3608] ----------------------------- [ 50.081731][ T3608] include/net/sock.h:592 suspicious rcu_dereference_check() usage! [ 50.089649][ T3608] [ 50.089649][ T3608] other info that might help us debug this: [ 50.089649][ T3608] [ 50.099909][ T3608] [ 50.099909][ T3608] rcu_scheduler_active = 2, debug_locks = 1 [ 50.107994][ T3608] 4 locks held by syz-executor290/3608: [ 50.113603][ T3608] #0: ffff8880743bbe10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release+0x86/0x280 [ 50.124219][ T3608] #1: ffffc900014f59e8 (&table->hash[i].lock){+...}-{2:2}, at: udp_lib_unhash+0x1d5/0x730 [ 50.135518][ T3608] #2: ffffffff8d7beb78 (reuseport_lock){+...}-{2:2}, at: reuseport_detach_sock+0x22/0x4a0 [ 50.145623][ T3608] #3: ffff88801c0733b8 (clock-AF_INET6){++..}-{2:2}, at: bpf_sk_reuseport_detach+0x26/0x190 [ 50.155964][ T3608] [ 50.155964][ T3608] stack backtrace: [ 50.161896][ T3608] CPU: 1 PID: 3608 Comm: syz-executor290 Not tainted 6.0.0-rc1-next-20220818-syzkaller #0 [ 50.171797][ T3608] syz-executor290[3608] cmdline: a [ 50.177611][ T3608] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 [ 50.187669][ T3608] Call Trace: [ 50.190952][ T3608] [ 50.193910][ T3608] dump_stack_lvl+0xcd/0x134 [ 50.198529][ T3608] bpf_sk_reuseport_detach+0x156/0x190 [ 50.204011][ T3608] reuseport_detach_sock+0x8c/0x4a0 [ 50.209232][ T3608] udp_lib_unhash+0x210/0x730 [ 50.213922][ T3608] ? udpv6_pre_connect+0x180/0x180 [ 50.219043][ T3608] sk_common_release+0xba/0x390 [ 50.223907][ T3608] inet_release+0x12e/0x270 [ 50.228435][ T3608] inet6_release+0x4c/0x70 [ 50.232865][ T3608] __sock_release+0xcd/0x280 [ 50.237493][ T3608] sock_close+0x18/0x20 [ 50.241682][ T3608] __fput+0x27c/0xa90 [ 50.245702][ T3608] ? __sock_release+0x280/0x280 [ 50.250573][ T3608] task_work_run+0xdd/0x1a0 [ 50.255088][ T3608] do_exit+0xc39/0x2b60 [ 50.259260][ T3608] ? lock_downgrade+0x6e0/0x6e0 [ 50.264138][ T3608] ? do_raw_spin_lock+0x120/0x2a0 [ 50.269179][ T3608] ? mm_update_next_owner+0x7a0/0x7a0 [ 50.274561][ T3608] ? rwlock_bug.part.0+0x90/0x90 [ 50.279512][ T3608] ? _raw_spin_unlock_irq+0x1f/0x40 [ 50.284720][ T3608] ? _raw_spin_unlock_irq+0x1f/0x40 [ 50.289932][ T3608] do_group_exit+0xd0/0x2a0 [ 50.294446][ T3608] __x64_sys_exit_group+0x3a/0x50 [ 50.299486][ T3608] do_syscall_64+0x35/0xb0 [ 50.303926][ T3608] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 50.309830][ T3608] RIP: 0033:0x7f8e61f76679 [ 50.314257][ T3608] Code: Unable to access opcode bytes at RIP 0x7f8e61f7664f. [ 50.321620][ T3608] RSP: 002b:00007ffd1a26b548 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 50.330057][ T3608] RAX: ffffffffffffffda RBX: 00007f8e61fea270 RCX: 00007f8e61f76679 [ 50.338033][ T3608] RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 [ 50.346013][ T3608] RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000000000 +++ exited with 0 +++ [ 50.353997][ T3608] R10: 0000000000000004 R11: 0000000000000246