./strace-static-x86_64 -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f ./syz-executor2967113394 <...> Warning: Permanently added '10.128.0.249' (ED25519) to the list of known hosts. execve("./syz-executor2967113394", ["./syz-executor2967113394"], 0x7ffd735416e0 /* 10 vars */) = 0 brk(NULL) = 0x555588ba6000 brk(0x555588ba6d00) = 0x555588ba6d00 arch_prctl(ARCH_SET_FS, 0x555588ba6380) = 0 set_tid_address(0x555588ba6650) = 5833 set_robust_list(0x555588ba6660, 24) = 0 rseq(0x555588ba6ca0, 0x20, 0, 0x53053053) = 0 prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0 readlink("/proc/self/exe", "/root/syz-executor2967113394", 4096) = 28 getrandom("\x6f\xb3\xa8\x8f\x2f\x1c\xd3\xfd", 8, GRND_NONBLOCK) = 8 brk(NULL) = 0x555588ba6d00 brk(0x555588bc7d00) = 0x555588bc7d00 brk(0x555588bc8000) = 0x555588bc8000 mprotect(0x7fda75b8c000, 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, child_tidptr=0x555588ba6650) = 5834 ./strace-static-x86_64: Process 5834 attached [pid 5833] openat(AT_FDCWD, "/sys/kernel/debug/x86/nmi_longest_ns", O_WRONLY|O_CLOEXEC [pid 5834] set_robust_list(0x555588ba6660, 24) = 0 [pid 5833] <... openat resumed>) = 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, "5834", 4) = 4 [pid 5833] close(3) = 0 [pid 5833] kill(5834, SIGKILL) = 0 [pid 5834] +++ killed by SIGKILL +++ --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_KILLED, si_pid=5834, si_uid=0, si_status=SIGKILL, si_utime=0, si_stime=0} --- mkdir("./syzkaller.qS7yLQ", 0700) = 0 chmod("./syzkaller.qS7yLQ", 0777) = 0 chdir("./syzkaller.qS7yLQ") = 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 [ 84.922634][ T5833] [ 84.925174][ T5833] ============================= [ 84.930162][ T5833] WARNING: suspicious RCU usage [ 84.935030][ T5833] 6.15.0-rc4-syzkaller-g079e5c56a5c4 #0 Not tainted [ 84.941679][ T5833] ----------------------------- [ 84.946543][ T5833] net/core/netclassid_cgroup.c:24 suspicious rcu_dereference_check() usage! [ 84.955331][ T5833] [ 84.955331][ T5833] other info that might help us debug this: [ 84.955331][ T5833] [ 84.965610][ 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) = ? [ 84.965610][ T5833] rcu_scheduler_active = 2, debug_locks = 1 [ 84.974145][ T5833] 1 lock held by syz-executor296/5833: [ 84.979740][ T5833] #0: ffffffff8df3ba40 (rcu_read_lock_trace){....}-{0:0}, at: rcu_read_lock_trace+0x38/0x80 [ 84.990000][ T5833] [ 84.990000][ T5833] stack backtrace: [ 84.995919][ T5833] CPU: 0 UID: 0 PID: 5833 Comm: syz-executor296 Not tainted 6.15.0-rc4-syzkaller-g079e5c56a5c4 #0 PREEMPT(full) [ 84.995937][ T5833] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 [ 84.995952][ T5833] Call Trace: [ 84.995960][ T5833] [ 84.995967][ T5833] dump_stack_lvl+0x189/0x250 [ 84.995996][ T5833] ? __pfx_dump_stack_lvl+0x10/0x10 [ 84.996017][ T5833] ? __pfx__printk+0x10/0x10 [ 84.996045][ T5833] lockdep_rcu_suspicious+0x140/0x1d0 [ 84.996070][ T5833] task_cls_state+0x1a5/0x1d0 [ 84.996091][ T5833] bpf_get_cgroup_classid_curr+0x18/0x60 [ 84.996106][ T5833] bpf_prog_83da9cb0e78d4768+0x2c/0x5a [ 84.996124][ T5833] bpf_prog_run_pin_on_cpu+0x67/0x150 [ 84.996144][ T5833] bpf_prog_test_run_syscall+0x312/0x4b0 [ 84.996163][ T5833] ? __pfx_bpf_prog_test_run_syscall+0x10/0x10 [ 84.996185][ T5833] ? __pfx_bpf_prog_test_run_syscall+0x10/0x10 [ 84.996202][ T5833] bpf_prog_test_run+0x2a9/0x340 [ 84.996225][ T5833] __sys_bpf+0x4a4/0x860 [ 84.996243][ T5833] ? __pfx___sys_bpf+0x10/0x10 [ 84.996271][ T5833] ? rcu_is_watching+0x15/0xb0 [ 84.996300][ T5833] __x64_sys_bpf+0x7c/0x90 [ 84.996317][ T5833] do_syscall_64+0xf6/0x210 [ 84.996336][ T5833] ? clear_bhb_loop+0x45/0xa0 [ 84.996353][ T5833] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 84.996366][ T5833] RIP: 0033:0x7fda75b18a69 [ 84.996379][ 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 [ 84.996390][ T5833] RSP: 002b:00007ffdd0546d48 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 [ 84.996404][ T5833] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fda75b18a69 [ 84.996413][ T5833] RDX: 0000000000000048 RSI: 0000200000000500 RDI: 000000000000000a +++ exited with 0 +++ [ 84.996