[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.105231] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 24.669216] random: sshd: uninitialized urandom read (32 bytes read) [ 25.127920] random: sshd: uninitialized urandom read (32 bytes read) [ 25.660767] random: sshd: uninitialized urandom read (32 bytes read) [ 25.831615] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.63' (ECDSA) to the list of known hosts. [ 31.422373] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 31.516071] [ 31.517711] ============================================ [ 31.523135] WARNING: possible recursive locking detected [ 31.528659] 4.18.0-rc8+ #179 Not tainted [ 31.532703] -------------------------------------------- [ 31.538131] syz-executor314/4399 is trying to acquire lock: [ 31.543835] (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 31.554789] [ 31.554789] but task is already holding lock: [ 31.560744] (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 31.570364] [ 31.570364] other info that might help us debug this: [ 31.577006] Possible unsafe locking scenario: [ 31.577006] [ 31.583143] CPU0 [ 31.585699] ---- [ 31.588252] lock(&(&tlocks[i])->rlock); [ 31.592373] lock(&(&tlocks[i])->rlock); [ 31.596515] [ 31.596515] *** DEADLOCK *** [ 31.596515] [ 31.602551] May be due to missing lock nesting notation [ 31.602551] [ 31.609470] 3 locks held by syz-executor314/4399: [ 31.614307] #0: (____ptrval____) (cb_lock){++++}, at: genl_rcv+0x19/0x40 [ 31.621243] #1: (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 31.631204] #2: (____ptrval____) (rcu_read_lock){....}, at: rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 31.641997] [ 31.641997] stack backtrace: [ 31.646606] CPU: 0 PID: 4399 Comm: syz-executor314 Not tainted 4.18.0-rc8+ #179 [ 31.654051] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.663399] Call Trace: [ 31.665973] dump_stack+0x1c9/0x2b4 [ 31.669587] ? dump_stack_print_info.cold.2+0x52/0x52 [ 31.674770] ? ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 31.680109] ? vprintk_func+0x81/0xe7 [ 31.683892] __lock_acquire.cold.65+0x1fb/0x486 [ 31.688689] ? __lock_acquire+0x7fc/0x5020 [ 31.692916] ? trace_hardirqs_on+0x10/0x10 [ 31.697133] ? trace_hardirqs_on+0x10/0x10 [ 31.701345] ? __lock_acquire+0x7fc/0x5020 [ 31.705554] ? rcu_is_watching+0x8c/0x150 [ 31.709679] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 31.714152] ? trace_hardirqs_on+0x10/0x10 [ 31.718483] ? __kernel_text_address+0xd/0x40 [ 31.722958] ? unwind_get_return_address+0x61/0xa0 [ 31.727892] ? __save_stack_trace+0x8d/0xf0 [ 31.732194] ? add_lock_to_list.isra.30+0x1ec/0x4b0 [ 31.737321] ? trace_hardirqs_off+0x10/0x10 [ 31.741722] ? save_stack_trace+0x1a/0x20 [ 31.745850] ? save_trace+0xe0/0x290 [ 31.749545] ? kasan_check_read+0x11/0x20 [ 31.753676] ? __lock_acquire+0x28d9/0x5020 [ 31.758001] lock_acquire+0x1e4/0x540 [ 31.761779] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 31.768489] ? rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 31.775142] ? lock_release+0xa30/0xa30 [ 31.779093] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 31.784366] _raw_spin_lock_bh+0x31/0x40 [ 31.788415] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 31.795235] rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 31.801709] ? kasan_check_read+0x11/0x20 [ 31.805834] ? rcu_is_watching+0x8c/0x150 [ 31.809954] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 31.814355] ? rhashtable_replace_fast.isra.20.constprop.24+0xb60/0xb60 [ 31.821082] ? rhashtable_lookup_fast.isra.18.constprop.30+0x5a3/0xa60 [ 31.827724] ? parse_nl_config.isra.13+0x550/0x550 [ 31.832645] ? lock_acquire+0x25f/0x540 [ 31.836601] ? do_csum+0x345/0x410 [ 31.840120] ? lock_release+0xa30/0xa30 [ 31.844069] ? csum_partial+0x21/0x30 [ 31.848028] ? ila_init_saved_csum+0x9b/0x330 [ 31.852505] ? kasan_check_write+0x14/0x20 [ 31.856819] ? do_raw_spin_lock+0xc1/0x200 [ 31.861042] ila_xlat_nl_cmd_add_mapping+0xafe/0x17e0 [ 31.866214] ? depot_save_stack+0x291/0x470 [ 31.870647] ? __rhashtable_remove_fast.constprop.25+0xe30/0xe30 [ 31.876884] ? __kmalloc+0x14e/0x760 [ 31.880577] ? genl_rcv_msg+0xc6/0x168 [ 31.884437] ? netlink_rcv_skb+0x172/0x440 [ 31.888651] ? genl_rcv+0x28/0x40 [ 31.892082] ? netlink_unicast+0x5a0/0x760 [ 31.896298] ? netlink_sendmsg+0xa18/0xfc0 [ 31.900535] ? sock_sendmsg+0xd5/0x120 [ 31.904403] ? ___sys_sendmsg+0x7fd/0x930 [ 31.908524] ? __sys_sendmsg+0x11d/0x290 [ 31.912568] ? __x64_sys_sendmsg+0x78/0xb0 [ 31.916791] ? do_syscall_64+0x1b9/0x820 [ 31.920830] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 31.926176] ? find_held_lock+0x36/0x1c0 [ 31.930218] ? print_usage_bug+0xc0/0xc0 [ 31.934267] ? graph_lock+0x170/0x170 [ 31.938039] ? __lock_is_held+0xb5/0x140 [ 31.942093] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 31.947260] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 31.952354] ? validate_nla+0x2d9/0x7b0 [ 31.956411] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 31.961939] ? nla_parse+0x32b/0x4e0 [ 31.965631] ? __netlink_ns_capable+0x100/0x130 [ 31.970278] genl_family_rcv_msg+0x8a3/0x1140 [ 31.974752] ? genl_unregister_family+0x8b0/0x8b0 [ 31.979594] ? lock_downgrade+0x8f0/0x8f0 [ 31.983722] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 31.988884] ? kasan_check_read+0x11/0x20 [ 31.993018] ? lock_acquire+0x1e4/0x540 [ 31.996973] ? genl_rcv+0x19/0x40 [ 32.000404] ? radix_tree_lookup+0x21/0x30 [ 32.004618] genl_rcv_msg+0xc6/0x168 [ 32.008312] netlink_rcv_skb+0x172/0x440 [ 32.012354] ? genl_family_rcv_msg+0x1140/0x1140 [ 32.017090] ? netlink_ack+0xbe0/0xbe0 [ 32.020954] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 32.025337] genl_rcv+0x28/0x40 [ 32.028601] netlink_unicast+0x5a0/0x760 [ 32.032759] ? netlink_attachskb+0x9a0/0x9a0 [ 32.037148] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 32.042664] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 32.047658] netlink_sendmsg+0xa18/0xfc0 [ 32.051695] ? netlink_unicast+0x760/0x760 [ 32.055909] ? move_addr_to_kernel.part.18+0x100/0x100 [ 32.061186] ? security_socket_sendmsg+0x94/0xc0 [ 32.065920] ? netlink_unicast+0x760/0x760 [ 32.070215] sock_sendmsg+0xd5/0x120 [ 32.073922] ___sys_sendmsg+0x7fd/0x930 [ 32.077878] ? copy_msghdr_from_user+0x580/0x580 [ 32.082615] ? graph_lock+0x170/0x170 [ 32.086399] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 32.091916] ? __fget_light+0x2f7/0x440 [ 32.095865] ? fget_raw+0x20/0x20 [ 32.099345] ? lock_downgrade+0x8f0/0x8f0 [ 32.103496] ? handle_mm_fault+0x8c4/0xc80 [ 32.107797] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 32.113343] ? sockfd_lookup_light+0xc5/0x160 [ 32.117860] __sys_sendmsg+0x11d/0x290 [ 32.121728] ? __ia32_sys_shutdown+0x80/0x80 [ 32.126216] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 32.131837] ? __do_page_fault+0x449/0xe50 [ 32.136061] __x64_sys_sendmsg+0x78/0xb0 [ 32.140114] do_syscall_64+0x1b9/0x820 [ 32.143990] ? syscall_return_slowpath+0x5e0/0x5e0 [ 32.148899] ? syscall_return_slowpath+0x31d/0x5e0 [ 32.153813] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 32.159332] ? retint_user+0x18/0x18 [ 32.163027] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 32.167860] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 32.173032] RIP: 0033:0x4400f9 [ 32.176266] 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 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 32.195358] RSP: 002b:00007ffcbe619f18 EFLAGS: 00000213 ORIG_RAX: 000000000000002e [ 32.203045] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004400f9 [ 32.210297] RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000003 [ 32.217546] RB