Warning: Permanently added '10.128.0.56' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 109.035112][ T9803] IPVS: ftp: loaded support on port[0] = 21 [ 109.064819][ T9803] [ 109.067170][ T9803] ====================================================== [ 109.074171][ T9803] WARNING: possible circular locking dependency detected [ 109.081175][ T9803] 5.6.0-rc1-syzkaller #0 Not tainted [ 109.086481][ T9803] ------------------------------------------------------ [ 109.093482][ T9803] syz-executor922/9803 is trying to acquire lock: [ 109.099872][ T9803] ffffe8ffffc50f98 (&l->lock){....}, at: bpf_lru_push_free+0xe5/0x5b0 [ 109.108083][ T9803] [ 109.108083][ T9803] but task is already holding lock: [ 109.115453][ T9803] ffff88809f766a60 (&htab->buckets[i].lock){....}, at: __htab_map_lookup_and_delete_batch+0x617/0x1540 [ 109.126594][ T9803] [ 109.126594][ T9803] which lock already depends on the new lock. [ 109.126594][ T9803] [ 109.136981][ T9803] [ 109.136981][ T9803] the existing dependency chain (in reverse order) is: [ 109.145981][ T9803] [ 109.145981][ T9803] -> #1 (&htab->buckets[i].lock){....}: [ 109.153691][ T9803] _raw_spin_lock_irqsave+0x95/0xcd [ 109.159396][ T9803] htab_lru_map_delete_node+0xce/0x2f0 [ 109.165383][ T9803] __bpf_lru_list_shrink+0xf9/0x470 [ 109.171090][ T9803] bpf_lru_pop_free+0xa9f/0x1670 [ 109.176529][ T9803] prealloc_lru_pop+0x2c/0xa0 [ 109.181712][ T9803] __htab_lru_percpu_map_update_elem+0x67e/0xa90 [ 109.188558][ T9803] bpf_percpu_hash_update+0x16e/0x210 [ 109.194830][ T9803] bpf_map_update_value.isra.0+0x2d7/0x8e0 [ 109.201149][ T9803] __do_sys_bpf+0x3163/0x41e0 [ 109.206338][ T9803] __x64_sys_bpf+0x73/0xb0 [ 109.211283][ T9803] do_syscall_64+0xfa/0x790 [ 109.216296][ T9803] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 109.222798][ T9803] [ 109.222798][ T9803] -> #0 (&l->lock){....}: [ 109.229307][ T9803] __lock_acquire+0x2596/0x4a00 [ 109.234779][ T9803] lock_acquire+0x190/0x410 [ 109.239793][ T9803] _raw_spin_lock_irqsave+0x95/0xcd [ 109.245506][ T9803] bpf_lru_push_free+0xe5/0x5b0 [ 109.250859][ T9803] __htab_map_lookup_and_delete_batch+0x8d4/0x1540 [ 109.257871][ T9803] htab_lru_percpu_map_lookup_and_delete_batch+0x37/0x40 [ 109.265399][ T9803] bpf_map_do_batch+0x3f5/0x510 [ 109.270772][ T9803] __do_sys_bpf+0x1f7d/0x41e0 [ 109.275961][ T9803] __x64_sys_bpf+0x73/0xb0 [ 109.280890][ T9803] do_syscall_64+0xfa/0x790 [ 109.286053][ T9803] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 109.292462][ T9803] [ 109.292462][ T9803] other info that might help us debug this: [ 109.292462][ T9803] [ 109.302679][ T9803] Possible unsafe locking scenario: [ 109.302679][ T9803] [ 109.310116][ T9803] CPU0 CPU1 [ 109.315462][ T9803] ---- ---- [ 109.320801][ T9803] lock(&htab->buckets[i].lock); [ 109.325803][ T9803] lock(&l->lock); [ 109.332105][ T9803] lock(&htab->buckets[i].lock); [ 109.339637][ T9803] lock(&l->lock); [ 109.343425][ T9803] [ 109.343425][ T9803] *** DEADLOCK *** [ 109.343425][ T9803] [ 109.351558][ T9803] 2 locks held by syz-executor922/9803: [ 109.357110][ T9803] #0: ffffffff89bac240 (rcu_read_lock){....}, at: __htab_map_lookup_and_delete_batch+0x54b/0x1540 [ 109.367771][ T9803] #1: ffff88809f766a60 (&htab->buckets[i].lock){....}, at: __htab_map_lookup_and_delete_batch+0x617/0x1540 [ 109.379247][ T9803] [ 109.379247][ T9803] stack backtrace: [ 109.385131][ T9803] CPU: 0 PID: 9803 Comm: syz-executor922 Not tainted 5.6.0-rc1-syzkaller #0 [ 109.393779][ T9803] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 109.403848][ T9803] Call Trace: [ 109.407166][ T9803] dump_stack+0x197/0x210 [ 109.411494][ T9803] print_circular_bug.isra.0.cold+0x163/0x172 [ 109.417542][ T9803] check_noncircular+0x32e/0x3e0 [ 109.422477][ T9803] ? print_circular_bug.isra.0+0x230/0x230 [ 109.428310][ T9803] ? alloc_list_entry+0xc0/0xc0 [ 109.433149][ T9803] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 109.439372][ T9803] ? find_first_zero_bit+0x9a/0xc0 [ 109.444461][ T9803] __lock_acquire+0x2596/0x4a00 [ 109.449301][ T9803] ? mark_held_locks+0xf0/0xf0 [ 109.454061][ T9803] lock_acquire+0x190/0x410 [ 109.458557][ T9803] ? bpf_lru_push_free+0xe5/0x5b0 [ 109.463563][ T9803] _raw_spin_lock_irqsave+0x95/0xcd [ 109.468751][ T9803] ? bpf_lru_push_free+0xe5/0x5b0 [ 109.473763][ T9803] bpf_lru_push_free+0xe5/0x5b0 [ 109.478651][ T9803] __htab_map_lookup_and_delete_batch+0x8d4/0x1540 [ 109.485184][ T9803] ? __kasan_check_read+0x11/0x20 [ 109.490196][ T9803] ? htab_percpu_map_seq_show_elem+0x490/0x490 [ 109.496344][ T9803] ? htab_percpu_map_lookup_batch+0x40/0x40 [ 109.502220][ T9803] htab_lru_percpu_map_lookup_and_delete_batch+0x37/0x40 [ 109.509225][ T9803] bpf_map_do_batch+0x3f5/0x510 [ 109.514067][ T9803] __do_sys_bpf+0x1f7d/0x41e0 [ 109.518771][ T9803] ? find_held_lock+0x35/0x130 [ 109.523617][ T9803] ? bpf_prog_load+0x1820/0x1820 [ 109.528552][ T9803] ? lock_downgrade+0x920/0x920 [ 109.533382][ T9803] ? handle_mm_fault+0x292/0xa50 [ 109.538320][ T9803] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 109.543817][ T9803] ? do_syscall_64+0x26/0x790 [ 109.548487][ T9803] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 109.554540][ T9803] ? do_syscall_64+0x26/0x790 [ 109.559204][ T9803] __x64_sys_bpf+0x73/0xb0 [ 109.563601][ T9803] do_syscall_64+0xfa/0x790 [ 109.568102][ T9803] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 109.573975][ T9803] RIP: 0033:0x440c09 [ 109.577857][ T9803] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 7b 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 109.597449][ T9803] RSP: 002b:00007ffde7fc96c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 [ 109.605854][ T9803] RAX: ffffffffffffffda RBX: 00000000004a2390 RCX: 0000000000440c09 [ 109.614260][ T9803] RDX: 0000000000000038 RSI: 0000000020000100 RDI: 0000000000000019 [ 109.622219][ T9803] RBP: 00000000006cb018 R08: 0000000120080522 R09: 0000000120080522 [ 109.630181][ T9803] R10: 0000000120080522 R11: 0000000000000246 R12: 0000000000402110