[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.553808] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 25.306048] random: sshd: uninitialized urandom read (32 bytes read) [ 25.732493] random: sshd: uninitialized urandom read (32 bytes read) [ 26.256429] random: sshd: uninitialized urandom read (32 bytes read) [ 26.426309] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.13' (ECDSA) to the list of known hosts. [ 32.110435] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 32.205977] netlink: 'syz-executor077': attribute type 8 has an invalid length. [ 32.214444] [ 32.216077] ============================================ [ 32.221516] WARNING: possible recursive locking detected [ 32.227094] 4.18.0-rc8+ #179 Not tainted [ 32.231140] -------------------------------------------- [ 32.236578] syz-executor077/4391 is trying to acquire lock: [ 32.242353] (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 32.253193] [ 32.253193] but task is already holding lock: [ 32.259148] (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 32.268676] [ 32.268676] other info that might help us debug this: [ 32.275332] Possible unsafe locking scenario: [ 32.275332] [ 32.281364] CPU0 [ 32.283924] ---- [ 32.286482] lock(&(&tlocks[i])->rlock); [ 32.290633] lock(&(&tlocks[i])->rlock); [ 32.294763] [ 32.294763] *** DEADLOCK *** [ 32.294763] [ 32.300801] May be due to missing lock nesting notation [ 32.300801] [ 32.307775] 3 locks held by syz-executor077/4391: [ 32.312703] #0: (____ptrval____) (cb_lock){++++}, at: genl_rcv+0x19/0x40 [ 32.319705] #1: (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 32.329701] #2: (____ptrval____) (rcu_read_lock){....}, at: rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 32.340390] [ 32.340390] stack backtrace: [ 32.344944] CPU: 1 PID: 4391 Comm: syz-executor077 Not tainted 4.18.0-rc8+ #179 [ 32.352392] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 32.361731] Call Trace: [ 32.364319] dump_stack+0x1c9/0x2b4 [ 32.367934] ? dump_stack_print_info.cold.2+0x52/0x52 [ 32.373114] ? ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 32.378466] ? vprintk_func+0x81/0xe7 [ 32.382251] __lock_acquire.cold.65+0x1fb/0x486 [ 32.386905] ? __lock_acquire+0x7fc/0x5020 [ 32.391125] ? trace_hardirqs_on+0x10/0x10 [ 32.395352] ? trace_hardirqs_on+0x10/0x10 [ 32.399629] ? __lock_acquire+0x7fc/0x5020 [ 32.403853] ? rcu_is_watching+0x8c/0x150 [ 32.407986] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 32.412404] ? trace_hardirqs_on+0x10/0x10 [ 32.416627] ? __kernel_text_address+0xd/0x40 [ 32.421116] ? unwind_get_return_address+0x61/0xa0 [ 32.426038] ? __save_stack_trace+0x8d/0xf0 [ 32.430363] ? add_lock_to_list.isra.30+0x1ec/0x4b0 [ 32.435366] ? trace_hardirqs_off+0x10/0x10 [ 32.439671] ? save_stack_trace+0x1a/0x20 [ 32.443823] ? save_trace+0xe0/0x290 [ 32.447537] ? kasan_check_read+0x11/0x20 [ 32.451685] ? __lock_acquire+0x28d9/0x5020 [ 32.455994] lock_acquire+0x1e4/0x540 [ 32.459808] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 32.466473] ? rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 32.473124] ? lock_release+0xa30/0xa30 [ 32.477103] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 32.482301] _raw_spin_lock_bh+0x31/0x40 [ 32.486459] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 32.493181] rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 32.499679] ? kasan_check_read+0x11/0x20 [ 32.503986] ? rcu_is_watching+0x8c/0x150 [ 32.508126] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 32.512523] ? rhashtable_replace_fast.isra.20.constprop.24+0xb60/0xb60 [ 32.519284] ? rhashtable_lookup_fast.isra.18.constprop.30+0x5a3/0xa60 [ 32.525976] ? parse_nl_config.isra.13+0x550/0x550 [ 32.530897] ? lock_acquire+0x1e4/0x540 [ 32.534856] ? lock_release+0xa30/0xa30 [ 32.538886] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 32.544469] ? ila_init_saved_csum+0x9b/0x330 [ 32.548963] ? kasan_check_write+0x14/0x20 [ 32.553181] ? do_raw_spin_lock+0xc1/0x200 [ 32.557399] ila_xlat_nl_cmd_add_mapping+0xafe/0x17e0 [ 32.562627] ? wake_up_klogd+0x110/0x110 [ 32.566679] ? __rhashtable_remove_fast.constprop.25+0xe30/0xe30 [ 32.572820] ? mark_held_locks+0xc9/0x160 [ 32.576949] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 32.581511] ? vprintk_default+0x28/0x30 [ 32.585556] ? vprintk_func+0x81/0xe7 [ 32.589337] ? printk+0xa7/0xcf [ 32.592595] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 32.597374] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 32.602552] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 32.607552] ? validate_nla+0x2d9/0x7b0 [ 32.611510] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 32.617036] ? nla_parse+0x32b/0x4e0 [ 32.620760] ? __netlink_ns_capable+0x100/0x130 [ 32.625414] genl_family_rcv_msg+0x8a3/0x1140 [ 32.629892] ? genl_unregister_family+0x8b0/0x8b0 [ 32.634715] ? lock_downgrade+0x8f0/0x8f0 [ 32.638846] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 32.643848] ? kasan_check_read+0x11/0x20 [ 32.647982] ? lock_acquire+0x1e4/0x540 [ 32.651939] ? genl_rcv+0x19/0x40 [ 32.655382] ? radix_tree_lookup+0x21/0x30 [ 32.659600] genl_rcv_msg+0xc6/0x168 [ 32.663300] netlink_rcv_skb+0x172/0x440 [ 32.667345] ? genl_family_rcv_msg+0x1140/0x1140 [ 32.672083] ? netlink_ack+0xbe0/0xbe0 [ 32.675953] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 32.680343] genl_rcv+0x28/0x40 [ 32.683601] netlink_unicast+0x5a0/0x760 [ 32.687642] ? netlink_attachskb+0x9a0/0x9a0 [ 32.692040] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 32.697565] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 32.702576] netlink_sendmsg+0xa18/0xfc0 [ 32.706621] ? netlink_unicast+0x760/0x760 [ 32.710841] ? move_addr_to_kernel.part.18+0x100/0x100 [ 32.716100] ? security_socket_sendmsg+0x94/0xc0 [ 32.720961] ? netlink_unicast+0x760/0x760 [ 32.725181] sock_sendmsg+0xd5/0x120 [ 32.728880] ___sys_sendmsg+0x7fd/0x930 [ 32.732838] ? copy_msghdr_from_user+0x580/0x580 [ 32.737576] ? graph_lock+0x170/0x170 [ 32.741358] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 32.746882] ? __fget_light+0x2f7/0x440 [ 32.750839] ? fget_raw+0x20/0x20 [ 32.754285] ? lock_downgrade+0x8f0/0x8f0 [ 32.758419] ? handle_mm_fault+0x8c4/0xc80 [ 32.762641] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 32.768167] ? sockfd_lookup_light+0xc5/0x160 [ 32.772643] __sys_sendmsg+0x11d/0x290 [ 32.776512] ? __ia32_sys_shutdown+0x80/0x80 [ 32.780904] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 32.786423] ? __do_page_fault+0x449/0xe50 [ 32.790642] __x64_sys_sendmsg+0x78/0xb0 [ 32.794689] do_syscall_64+0x1b9/0x820 [ 32.798575] ? syscall_slow_exit_work+0x500/0x500 [ 32.803439] ? syscall_return_slowpath+0x5e0/0x5e0 [ 32.808366] ? syscall_return_slowpath+0x31d/0x5e0 [ 32.813277] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 32.818794] ? retint_user+0x18/0x18 [ 32.822489] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 32.827317] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 32.832490] RIP: 0033:0x4400e9 [ 32.835654] 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 [ 32.854751] RSP: 002b:00007ffd14495758 EFLAG