./strace-static-x86_64 -e \!wait4,clock_nanosleep,nanosleep -s 100 -x -f ./syz-executor1417341671 <...> Warning: Permanently added '10.128.0.79' (ED25519) to the list of known hosts. execve("./syz-executor1417341671", ["./syz-executor1417341671"], 0x7ffe73bcbfb0 /* 10 vars */) = 0 brk(NULL) = 0x555582cc7000 brk(0x555582cc7d00) = 0x555582cc7d00 arch_prctl(ARCH_SET_FS, 0x555582cc7380) = 0 set_tid_address(0x555582cc7650) = 5082 set_robust_list(0x555582cc7660, 24) = 0 rseq(0x555582cc7ca0, 0x20, 0, 0x53053053) = 0 prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0 readlink("/proc/self/exe", "/root/syz-executor1417341671", 4096) = 28 getrandom("\x61\x1e\xb8\x57\xf9\xd3\x2f\xe8", 8, GRND_NONBLOCK) = 8 brk(NULL) = 0x555582cc7d00 brk(0x555582ce8d00) = 0x555582ce8d00 brk(0x555582ce9000) = 0x555582ce9000 mprotect(0x7f4fcfefc000, 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 clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x555582cc7650) = 5083 ./strace-static-x86_64: Process 5083 attached [pid 5083] set_robust_list(0x555582cc7660, 24) = 0 [pid 5083] prctl(PR_SET_PDEATHSIG, SIGKILL) = 0 [pid 5083] setpgid(0, 0) = 0 [pid 5083] openat(AT_FDCWD, "/proc/self/oom_score_adj", O_WRONLY|O_CLOEXEC) = 3 [pid 5083] write(3, "1000", 4) = 4 [pid 5083] close(3) = 0 [pid 5083] bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_LPM_TRIE, key_size=8, value_size=65537, max_entries=9, map_flags=BPF_F_NO_PREALLOC, 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 [pid 5083] bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_RAW_TRACEPOINT, insn_cnt=12, insns=0x20000740, license="GPL", log_level=0, log_size=0, log_buf=NULL, kern_version=KERNEL_VERSION(0, 0, 0), prog_flags=0, prog_name="", prog_ifindex=0, expected_attach_type=BPF_CGROUP_INET_INGRESS, prog_btf_fd=-1, func_info_rec_size=0, func_info=NULL, func_info_cnt=0, line_info_rec_size=0, line_info=NULL, line_info_cnt=0, attach_btf_id=0, attach_prog_fd=0, fd_array=NULL}, 144) = 4 [pid 5083] bpf(BPF_RAW_TRACEPOINT_OPEN, {raw_tracepoint={name="timer_start", prog_fd=4}}, 16) = 5 [ 57.600542][ T5077] [ 57.602916][ T5077] ====================================================== [ 57.609917][ T5077] WARNING: possible circular locking dependency detected [ 57.616916][ T5077] 6.9.0-rc6-syzkaller-01468-g173e7622ccb3 #0 Not tainted [ 57.623911][ T5077] ------------------------------------------------------ [ 57.630903][ T5077] sshd/5077 is trying to acquire lock: [ 57.636333][ T5077] ffff8880b9529430 (krc.lock){....}-{2:2}, at: kvfree_call_rcu+0x18a/0x790 [ 57.644940][ T5077] [ 57.644940][ T5077] but task is already holding lock: [ 57.652278][ T5077] ffff8880b952a718 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x112/0x240 [ 57.661117][ T5077] [ 57.661117][ T5077] which lock already depends on the new lock. [ 57.661117][ T5077] [ 57.671493][ T5077] [ 57.671493][ T5077] the existing dependency chain (in reverse order) is: [ 57.680482][ T5077] [ 57.680482][ T5077] -> #1 (&base->lock){-.-.}-{2:2}: [ 57.687751][ T5077] lock_acquire+0x1ed/0x550 [ 57.692753][ T5077] _raw_spin_lock_irqsave+0xd5/0x120 [ 57.698734][ T5077] lock_timer_base+0x112/0x240 [ 57.704012][ T5077] __mod_timer+0x1ca/0xeb0 [ 57.708925][ T5077] queue_delayed_work_on+0x15a/0x260 [ 57.714722][ T5077] kvfree_call_rcu+0x47f/0x790 [ 57.719997][ T5077] rtnl_register_internal+0x482/0x590 [ 57.725894][ T5077] rtnl_register+0x36/0x80 [ 57.730819][ T5077] ip_rt_init+0x2f5/0x3a0 [ 57.735663][ T5077] ip_init+0xe/0x20 [ 57.739973][ T5077] inet_init+0x3d8/0x580 [ 57.744715][ T5077] do_one_initcall+0x248/0x880 [ 57.749978][ T5077] do_initcall_level+0x157/0x210 [ 57.755413][ T5077] do_initcalls+0x3f/0x80 [ 57.760237][ T5077] kernel_init_freeable+0x435/0x5d0 [ 57.765933][ T5077] kernel_init+0x1d/0x2b0 [ 57.770778][ T5077] ret_from_fork+0x4b/0x80 [ 57.775698][ T5077] ret_from_fork_asm+0x1a/0x30 [ 57.780963][ T5077] [ 57.780963][ T5077] -> #0 (krc.lock){....}-{2:2}: [ 57.787974][ T5077] validate_chain+0x18cb/0x58e0 [ 57.793323][ T5077] __lock_acquire+0x1346/0x1fd0 [ 57.798683][ T5077] lock_acquire+0x1ed/0x550 [ 57.803711][ T5077] _raw_spin_lock+0x2e/0x40 [ 57.808715][ T5077] kvfree_call_rcu+0x18a/0x790 [ 57.813976][ T5077] trie_delete_elem+0x546/0x6a0 [ 57.819324][ T5077] bpf_prog_2c29ac5cdc6b1842+0x42/0x46 [ 57.825283][ T5077] bpf_trace_run2+0x2ec/0x540 [ 57.830459][ T5077] enqueue_timer+0x3ce/0x570 [ 57.835547][ T5077] __mod_timer+0x953/0xeb0 [ 57.840461][ T5077] sk_reset_timer+0x23/0xc0 [ 57.845461][ T5077] tcp_schedule_loss_probe+0x419/0x560 [ 57.851424][ T5077] tcp_write_xmit+0x42c9/0x69d0 [ 57.856775][ T5077] __tcp_push_pending_frames+0x9b/0x360 [ 57.862820][ T5077] tcp_sendmsg_locked+0x4313/0x4d70 [ 57.868518][ T5077] tcp_sendmsg+0x30/0x50 [ 57.873259][ T5077] __sock_sendmsg+0x1a6/0x270 [ 57.878451][ T5077] sock_write_iter+0x2dd/0x400 [ 57.883715][ T5077] vfs_write+0xa84/0xcb0 [ 57.888459][ T5077] ksys_write+0x1a0/0x2c0 [ 57.893291][ T5077] do_syscall_64+0xf5/0x240 [ 57.898295][ T5077] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 57.904687][ T5077] [ 57.904687][ T5077] other info that might help us debug this: [ 57.904687][ T5077] [ 57.914891][ T5077] Possible unsafe locking scenario: [ 57.914891][ T5077] [ 57.922317][ T5077] CPU0 CPU1 [ 57.927660][ T5077] ---- ---- [ 57.933000][ T5077] lock(&base->lock); [ 57.937051][ T5077] lock(krc.lock); [ 57.943357][ T5077] lock(&base->lock); [ 57.949926][ T5077] lock(krc.lock); [ 57.953717][ T5077] [ 57.953717][ T5077] *** DEADLOCK *** [ 57.953717][ T5077] [ 57.961848][ T5077] 3 locks held by sshd/5077: [ 57.966410][ T5077] #0: ffff88804f419ad8 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x22/0x50 [ 57.975520][ T5077] #1: ffff8880b952a718 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x112/0x240 [ 57.984796][ T5077] #2: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 [ 57.994162][ T5077] [ 57.994162][ T5077] stack backtrace: [ 58.000025][ T5077] CPU: 1 PID: 5077 Comm: sshd Not tainted 6.9.0-rc6-syzkaller-01468-g173e7622ccb3 #0 [ 58.009453][ T5077] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 [ 58.019493][ T5077] Call Trace: [ 58.022754][ T5077] [ 58.025671][ T5077] dump_stack_lvl+0x241/0x360 [ 58.030338][ T5077] ? __pfx_dump_stack_lvl+0x10/0x10 [ 58.035517][ T5077] ? print_circular_bug+0x130/0x1a0 [ 58.040697][ T5077] check_noncircular+0x36a/0x4a0 [ 58.045614][ T5077] ? __pfx_check_noncircular+0x10/0x10 [ 58.051050][ T5077] ? lockdep_lock+0x123/0x2b0 [ 58.055708][ T5077] ? __pfx_validate_chain+0x10/0x10 [ 58.060885][ T5077] ? check_sq_full_and_disable+0x1a4/0x320 [ 58.066672][ T5077] ? _find_first_zero_bit+0xd4/0x100 [ 58.071939][ T5077] validate_chain+0x18cb/0x58e0 [ 58.076776][ T5077] ? __pfx_validate_chain+0x10/0x10 [ 58.081951][ T5077] ? __pfx_validate_chain+0x10/0x10 [ 58.087128][ T5077] ? mark_lock+0x9a/0x350 [ 58.091436][ T5077] ? __lock_acquire+0x1346/0x1fd0 [ 58.096442][ T5077] ? mark_lock+0x9a/0x350 [ 58.100752][ T5077] ? mark_lock+0x9a/0x350 [ 58.105060][ T5077] __lock_acquire+0x1346/0x1fd0 [ 58.109889][ T5077] lock_acquire+0x1ed/0x550 [ 58.114366][ T5077] ? kvfree_call_rcu+0x18a/0x790 [ 58.119283][ T5077] ? __pfx_lock_acquire+0x10/0x10 [ 58.124289][ T5077] ? debug_object_active_state+0x239/0x360 [ 58.130074][ T5077] ? __pfx_debug_object_active_state+0x10/0x10 [ 58.136203][ T5077] ? __virt_addr_valid+0x183/0x520 [ 58.141294][ T5077] ? __virt_addr_valid+0x183/0x520 [ 58.146390][ T5077] ? __virt_addr_valid+0x44e/0x520 [ 58.151482][ T5077] ? __phys_addr+0xba/0x170 [ 58.155982][ T5077] _raw_spin_lock+0x2e/0x40 [ 58.160466][ T5077] ? kvfree_call_rcu+0x18a/0x790 [ 58.165380][ T5077] kvfree_call_rcu+0x18a/0x790 [ 58.170124][ T5077] ? _raw_spin_unlock_irqrestore+0xdd/0x140 [ 58.175997][ T5077] ? __pfx_kvfree_call_rcu+0x10/0x10 [ 58.181260][ T5077] ? longest_prefix_match+0x33d/0x670 [ 58.186615][ T5077] trie_delete_elem+0x546/0x6a0 [ 58.191449][ T5077] ? bpf_trace_run2+0x1fc/0x540 [ 58.196277][ T5077] bpf_prog_2c29ac5cdc6b1842+0x42/0x46 [ 58.201709][ T5077] bpf_trace_run2+0x2ec/0x540 [ 58.206367][ T5077] ? __pfx_bpf_trace_run2+0x10/0x10 [ 58.211543][ T5077] ? __pfx_debug_object_activate+0x10/0x10 [ 58.217329][ T5077] enqueue_timer+0x3ce/0x570 [ 58.221900][ T5077] __mod_timer+0x953/0xeb0 [ 58.226295][ T5077] ? __pfx___mod_timer+0x10/0x10 [ 58.231214][ T5077] ? __asan_memset+0x23/0x50 [ 58.235785][ T5077] sk_reset_timer+0x23/0xc0 [ 58.240268][ T5077] tcp_schedule_loss_probe+0x419/0x560 [ 58.245708][ T5077] tcp_write_xmit+0x42c9/0x69d0 [ 58.250545][ T5077] ? _copy_from_iter+0x26b/0x1960 [ 58.255547][ T5077] ? __pfx_lock_release+0x10/0x10 [ 58.260547][ T5077] ? __alloc_skb+0x2d5/0x440 [ 58.265120][ T5077] __tcp_push_pending_frames+0x9b/0x360 [ 58.270648][ T5077] tcp_sendmsg_locked+0x4313/0x4d70 [ 58.275851][ T5077] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10 [ 58.282155][ T5077] ? __pfx_tcp_sendmsg_locked+0x10/0x10 [ 58.287677][ T5077] ? __local_bh_enable_ip+0x168/0x200 [ 58.293026][ T5077] ? do_raw_spin_unlock+0x13c/0x8b0 [ 58.298205][ T5077] tcp_sendmsg+0x30/0x50 [ 58.302426][ T5077] __sock_sendmsg+0x1a6/0x270 [ 58.307079][ T5077] sock_write_iter+0x2dd/0x400 [ 58.311824][ T5077] ? __pfx_sock_write_iter+0x10/0x10 [ 58.317090][ T5077] ? bpf_lsm_file_permission+0x9/0x10 [ 58.322445][ T5077] ? security_file_permission+0x7f/0xa0 [ 58.327968][ T5077] vfs_write+0xa84/0xcb0 [ 58.332195][ T5077] ? __pfx_vfs_write+0x10/0x10 [ 58.336944][ T5077] ? __pfx_lock_acquire+0x10/0x10 [ 58.341945][ T5077] ? __fdget_pos+0x1a2/0x320 [ 58.346516][ T5077] ksys_write+0x1a0/0x2c0 [ 58.350827][ T5077] ? __pfx_ksys_write+0x10/0x10 [ 58.355657][ T5077] ? do_syscall_64+0x102/0x240 [ 58.360402][ T5077] ? do_syscall_64+0xb6/0x240 [ 58.365059][ T5077] do_syscall_64+0xf5/0x240 [ 58.369549][ T5077] ? clear_bhb_loop+0x35/0x90 [ 58.374204][ T5077] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 58.380073][ T5077] RIP: 0033:0x7fc15f516bf2 [ 58.384468][ T5077] Code: 89 c7 48 89 44 24 08 e8 7b 34 fa ff 48 8b 44 24 08 48 83 c4 28 c3 c3 64 8b 04 25 18 00 00 00 85 c0 75 20 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 6f 48 8b 15 07 a2 0d 00 f7 d8 64 89 02 48 83 [ 58.404048][ T5077] RSP: 002b:00007ffd21172e38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 58.412442][ T5077] RAX: ffffffffffffffda RBX: 000000000000002c RCX: 00007fc15f516bf2 [ 58.420390][ T5077] RDX: 000000000000002c RSI: 0000562a15270960 RDI: 0000000000000004 [ 58.428338][ T5077] RBP: 0000562a1527e220 R08: 0000000000000000 R09: 0000000000000000 [ 58.436283][ T5077] R10: 0000000000000000 R11: 0000000000000246 R12: 00005629f805daa4 [ 58.444235][ T5077] R13: 0000000000000039 R14: 00005629f805e3e8 R15: 00007ffd21172ea8 [ 58.452187][ T5077]