./strace-static-x86_64 -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f ./syz-executor2559216496 <...> Warning: Permanently added '10.128.0.143' (ED25519) to the list of known hosts. execve("./syz-executor2559216496", ["./syz-executor2559216496"], 0x7ffc83481580 /* 10 vars */) = 0 brk(NULL) = 0x55555e89f000 brk(0x55555e89fe00) = 0x55555e89fe00 arch_prctl(ARCH_SET_FS, 0x55555e89f480) = 0 set_tid_address(0x55555e89f750) = 5833 set_robust_list(0x55555e89f760, 24) = 0 rseq(0x55555e89fda0, 0x20, 0, 0x53053053) = 0 prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0 readlink("/proc/self/exe", "/root/syz-executor2559216496", 4096) = 28 getrandom("\xb0\xd2\xb9\xa7\xc6\x25\x44\x5a", 8, GRND_NONBLOCK) = 8 brk(NULL) = 0x55555e89fe00 brk(0x55555e8c0e00) = 0x55555e8c0e00 brk(0x55555e8c1000) = 0x55555e8c1000 mprotect(0x7f16d8c2a000, 16384, PROT_READ) = 0 mmap(0x1ffffffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x1ffffffff000 mmap(0x200000000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x200000000000 mmap(0x200001000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x200001000000 clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD./strace-static-x86_64: Process 5835 attached [pid 5835] set_robust_list(0x55555e89f760, 24 [pid 5833] <... clone resumed>, child_tidptr=0x55555e89f750) = 5835 [pid 5835] <... set_robust_list resumed>) = 0 [pid 5833] openat(AT_FDCWD, "/sys/kernel/debug/x86/nmi_longest_ns", O_WRONLY|O_CLOEXEC) = 3 [pid 5833] write(3, "10000000000", 11) = 11 [pid 5833] close(3) = 0 [pid 5833] openat(AT_FDCWD, "/proc/sys/kernel/hung_task_check_interval_secs", O_WRONLY|O_CLOEXEC) = 3 [pid 5833] write(3, "20", 2) = 2 [pid 5833] close(3) = 0 [pid 5833] openat(AT_FDCWD, "/proc/sys/net/core/bpf_jit_kallsyms", O_WRONLY|O_CLOEXEC) = 3 [pid 5833] write(3, "1", 1) = 1 [pid 5833] close(3) = 0 [pid 5833] openat(AT_FDCWD, "/proc/sys/net/core/bpf_jit_harden", O_WRONLY|O_CLOEXEC) = 3 [pid 5833] write(3, "0", 1) = 1 [pid 5833] close(3) = 0 [pid 5833] openat(AT_FDCWD, "/proc/sys/kernel/kptr_restrict", O_WRONLY|O_CLOEXEC) = 3 [pid 5833] write(3, "0", 1) = 1 [pid 5833] close(3) = 0 [pid 5833] openat(AT_FDCWD, "/proc/sys/kernel/softlockup_all_cpu_backtrace", O_WRONLY|O_CLOEXEC) = 3 [pid 5833] write(3, "1", 1) = 1 [pid 5833] close(3) = 0 [pid 5833] openat(AT_FDCWD, "/proc/sys/fs/mount-max", O_WRONLY|O_CLOEXEC) = 3 [pid 5833] write(3, "100", 3) = 3 [pid 5833] close(3) = 0 [pid 5833] openat(AT_FDCWD, "/proc/sys/vm/oom_dump_tasks", O_WRONLY|O_CLOEXEC) = 3 [pid 5833] write(3, "0", 1) = 1 [pid 5833] close(3) = 0 [pid 5833] openat(AT_FDCWD, "/proc/sys/debug/exception-trace", O_WRONLY|O_CLOEXEC) = 3 [pid 5833] write(3, "0", 1) = 1 [pid 5833] close(3) = 0 [pid 5833] openat(AT_FDCWD, "/proc/sys/kernel/printk", O_WRONLY|O_CLOEXEC) = 3 [pid 5833] write(3, "7 4 1 3", 7) = 7 [pid 5833] close(3) = 0 [pid 5833] openat(AT_FDCWD, "/proc/sys/kernel/keys/gc_delay", O_WRONLY|O_CLOEXEC) = 3 [pid 5833] write(3, "1", 1) = 1 [pid 5833] close(3) = 0 [pid 5833] openat(AT_FDCWD, "/proc/sys/vm/oom_kill_allocating_task", O_WRONLY|O_CLOEXEC) = 3 [pid 5833] write(3, "1", 1) = 1 [pid 5833] close(3) = 0 [pid 5833] openat(AT_FDCWD, "/proc/sys/kernel/ctrl-alt-del", O_WRONLY|O_CLOEXEC) = 3 [pid 5833] write(3, "0", 1) = 1 [pid 5833] close(3) = 0 [pid 5833] openat(AT_FDCWD, "/proc/sys/kernel/cad_pid", O_WRONLY|O_CLOEXEC) = 3 [pid 5833] write(3, "5835", 4) = 4 [pid 5833] close(3) = 0 [pid 5833] kill(5835, SIGKILL) = 0 [pid 5835] +++ killed by SIGKILL +++ --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_KILLED, si_pid=5835, si_uid=0, si_status=SIGKILL, si_utime=0, si_stime=0} --- rt_sigaction(SIGRTMIN, {sa_handler=SIG_IGN, sa_mask=[], sa_flags=0}, NULL, 8) = 0 rt_sigaction(SIGRT_1, {sa_handler=SIG_IGN, sa_mask=[], sa_flags=0}, NULL, 8) = 0 rt_sigaction(SIGSEGV, {sa_handler=0x7f16d8b85c30, sa_mask=[], sa_flags=SA_RESTORER|SA_NODEFER|SA_SIGINFO, sa_restorer=0x7f16d8b8ce10}, NULL, 8) = 0 rt_sigaction(SIGBUS, {sa_handler=0x7f16d8b85c30, sa_mask=[], sa_flags=SA_RESTORER|SA_NODEFER|SA_SIGINFO, sa_restorer=0x7f16d8b8ce10}, NULL, 8) = 0 mkdir("./syzkaller.vNSfpw", 0700) = 0 chmod("./syzkaller.vNSfpw", 0777) = 0 chdir("./syzkaller.vNSfpw") = 0 executing program write(1, "executing program\n", 18) = 18 bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_RINGBUF, key_size=0, value_size=0, max_entries=32768, map_flags=0, inner_map_fd=-1, map_name="", map_ifindex=0, btf_fd=-1, btf_key_type_id=0, btf_value_type_id=0, btf_vmlinux_value_type_id=0, map_extra=0}, 72) = 3 bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_SYSCALL, insn_cnt=13, insns=0x200000000100, license="GPL", log_level=0, log_size=0, log_buf=NULL, kern_version=KERNEL_VERSION(0, 0, 0), prog_flags=BPF_F_TEST_RND_HI32|BPF_F_SLEEPABLE|0x20, prog_name="", prog_ifindex=0, expected_attach_type=BPF_CGROUP_INET_INGRESS, prog_btf_fd=-1, func_info_rec_size=8, func_info=NULL, func_info_cnt=0, line_info_rec_size=16, line_info=NULL, line_info_cnt=0, attach_btf_id=0, attach_prog_fd=0, fd_array=NULL, ...}, 148) = 4 [ 88.098363][ T5833] [ 88.100858][ T5833] ============================= [ 88.105700][ T5833] WARNING: suspicious RCU usage [ 88.110871][ T5833] 6.15.0-rc4-syzkaller-g079e5c56a5c4 #0 Not tainted [ 88.117478][ T5833] ----------------------------- [ 88.122484][ T5833] net/core/netclassid_cgroup.c:24 suspicious rcu_dereference_check() usage! [ 88.131201][ T5833] [ 88.131201][ T5833] other info that might help us debug this: [ 88.131201][ T5833] [ 88.141462][ T5833] bpf(BPF_PROG_TEST_RUN, {test={prog_fd=4, retval=0, data_size_in=0, data_size_out=0, data_in=NULL, data_out=NULL, repeat=0, duration=0, ctx_size_in=0, ctx_size_out=0, ctx_in=NULL, ctx_out=NULL, flags=0, cpu=0}}, 72) = 0 exit_group(0) = ? +++ exited with 0 +++ [ 88.141462][ T5833] rcu_scheduler_active = 2, debug_locks = 1 [ 88.149565][ T5833] 1 lock held by syz-executor255/5833: [ 88.155031][ T5833] #0: ffffffff8df3ba40 (rcu_read_lock_trace){....}-{0:0}, at: rcu_read_lock_trace+0x38/0x80 [ 88.165321][ T5833] [ 88.165321][ T5833] stack backtrace: [ 88.171277][ T5833] CPU: 1 UID: 0 PID: 5833 Comm: syz-executor255 Not tainted 6.15.0-rc4-syzkaller-g079e5c56a5c4 #0 PREEMPT(full) [ 88.171296][ T5833] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 [ 88.171308][ T5833] Call Trace: [ 88.171317][ T5833] [ 88.171323][ T5833] dump_stack_lvl+0x189/0x250 [ 88.171353][ T5833] ? __pfx_dump_stack_lvl+0x10/0x10 [ 88.171374][ T5833] ? __pfx__printk+0x10/0x10 [ 88.171398][ T5833] lockdep_rcu_suspicious+0x140/0x1d0 [ 88.171423][ T5833] task_cls_state+0x1a5/0x1d0 [ 88.171443][ T5833] bpf_get_cgroup_classid_curr+0x18/0x60 [ 88.171459][ T5833] bpf_prog_83da9cb0e78d4768+0x2c/0x5a [ 88.171481][ T5833] bpf_prog_run_pin_on_cpu+0x67/0x150 [ 88.171501][ T5833] bpf_prog_test_run_syscall+0x312/0x4b0 [ 88.171521][ T5833] ? __pfx_bpf_prog_test_run_syscall+0x10/0x10 [ 88.171543][ T5833] ? __pfx_bpf_prog_test_run_syscall+0x10/0x10 [ 88.171561][ T5833] bpf_prog_test_run+0x2a9/0x340 [ 88.171583][ T5833] __sys_bpf+0x4a4/0x860 [ 88.171602][ T5833] ? __pfx___sys_bpf+0x10/0x10 [ 88.171631][ T5833] ? rcu_is_watching+0x15/0xb0 [ 88.171660][ T5833] __x64_sys_bpf+0x7c/0x90 [ 88.171676][ T5833] do_syscall_64+0xf6/0x210 [ 88.171697][ T5833] ? clear_bhb_loop+0x45/0xa0 [ 88.171713][ T5833] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 88.171727][ T5833] RIP: 0033:0x7f16d8bb6da9 [ 88.171739][ T5833] Code: d8 5b c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 [ 88.171750][ T5833] RSP: 002b:00007ffdae77bc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 [ 88.171764][ T5833] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f16d8bb6da9 [ 88.171774][ T5833] RDX: 0000000000000048 RSI: 0000200000000500 RDI: 000000