[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 21.457460] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 26.441905] random: sshd: uninitialized urandom read (32 bytes read) [ 26.776303] random: sshd: uninitialized urandom read (32 bytes read) [ 27.299521] random: sshd: uninitialized urandom read (32 bytes read) [ 27.478716] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.11' (ECDSA) to the list of known hosts. [ 32.978418] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 33.072505] netlink: 'syz-executor119': attribute type 8 has an invalid length. [ 33.080678] [ 33.082304] ============================================ [ 33.087733] WARNING: possible recursive locking detected [ 33.093181] 4.18.0-rc8+ #179 Not tainted [ 33.097219] -------------------------------------------- [ 33.102650] syz-executor119/4443 is trying to acquire lock: [ 33.108567] (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 33.119401] [ 33.119401] but task is already holding lock: [ 33.125352] (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 33.134877] [ 33.134877] other info that might help us debug this: [ 33.141525] Possible unsafe locking scenario: [ 33.141525] [ 33.147563] CPU0 [ 33.150123] ---- [ 33.152681] lock(&(&tlocks[i])->rlock); [ 33.156811] lock(&(&tlocks[i])->rlock); [ 33.160941] [ 33.160941] *** DEADLOCK *** [ 33.160941] [ 33.166976] May be due to missing lock nesting notation [ 33.166976] [ 33.173988] 3 locks held by syz-executor119/4443: [ 33.178943] #0: (____ptrval____) (cb_lock){++++}, at: genl_rcv+0x19/0x40 [ 33.185871] #1: (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 33.195834] #2: (____ptrval____) (rcu_read_lock){....}, at: rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 33.206488] [ 33.206488] stack backtrace: [ 33.210975] CPU: 0 PID: 4443 Comm: syz-executor119 Not tainted 4.18.0-rc8+ #179 [ 33.218509] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.227843] Call Trace: [ 33.230418] dump_stack+0x1c9/0x2b4 [ 33.234060] ? dump_stack_print_info.cold.2+0x52/0x52 [ 33.239249] ? ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 33.244597] ? vprintk_func+0x81/0xe7 [ 33.248383] __lock_acquire.cold.65+0x1fb/0x486 [ 33.253054] ? __lock_acquire+0x7fc/0x5020 [ 33.257291] ? trace_hardirqs_on+0x10/0x10 [ 33.261510] ? trace_hardirqs_on+0x10/0x10 [ 33.265726] ? __lock_acquire+0x7fc/0x5020 [ 33.269942] ? rcu_is_watching+0x8c/0x150 [ 33.274083] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 33.278480] ? trace_hardirqs_on+0x10/0x10 [ 33.282702] ? __kernel_text_address+0xd/0x40 [ 33.287181] ? unwind_get_return_address+0x61/0xa0 [ 33.292183] ? __save_stack_trace+0x8d/0xf0 [ 33.296517] ? add_lock_to_list.isra.30+0x1ec/0x4b0 [ 33.301519] ? trace_hardirqs_off+0x10/0x10 [ 33.305825] ? save_stack_trace+0x1a/0x20 [ 33.309962] ? save_trace+0xe0/0x290 [ 33.313675] ? kasan_check_read+0x11/0x20 [ 33.317807] ? __lock_acquire+0x28d9/0x5020 [ 33.322117] lock_acquire+0x1e4/0x540 [ 33.326297] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 33.332954] ? rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 33.339614] ? lock_release+0xa30/0xa30 [ 33.343577] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 33.348895] _raw_spin_lock_bh+0x31/0x40 [ 33.352947] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 33.359601] rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 33.366096] ? kasan_check_read+0x11/0x20 [ 33.370233] ? rcu_is_watching+0x8c/0x150 [ 33.374364] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 33.378858] ? rhashtable_replace_fast.isra.20.constprop.24+0xb60/0xb60 [ 33.385605] ? rhashtable_lookup_fast.isra.18.constprop.30+0x5a3/0xa60 [ 33.392269] ? parse_nl_config.isra.13+0x550/0x550 [ 33.397188] ? lock_acquire+0x1e4/0x540 [ 33.401152] ? lock_release+0xa30/0xa30 [ 33.405214] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 33.410737] ? ila_init_saved_csum+0x9b/0x330 [ 33.415222] ? kasan_check_write+0x14/0x20 [ 33.419462] ? do_raw_spin_lock+0xc1/0x200 [ 33.423755] ila_xlat_nl_cmd_add_mapping+0xafe/0x17e0 [ 33.428937] ? wake_up_klogd+0x110/0x110 [ 33.432987] ? __rhashtable_remove_fast.constprop.25+0xe30/0xe30 [ 33.439124] ? mark_held_locks+0xc9/0x160 [ 33.443254] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 33.447819] ? vprintk_default+0x28/0x30 [ 33.451863] ? vprintk_func+0x81/0xe7 [ 33.455646] ? printk+0xa7/0xcf [ 33.458914] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 33.463656] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 33.468846] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 33.473844] ? validate_nla+0x2d9/0x7b0 [ 33.477803] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 33.483325] ? nla_parse+0x32b/0x4e0 [ 33.487057] ? __netlink_ns_capable+0x100/0x130 [ 33.491723] genl_family_rcv_msg+0x8a3/0x1140 [ 33.496268] ? genl_unregister_family+0x8b0/0x8b0 [ 33.501102] ? lock_downgrade+0x8f0/0x8f0 [ 33.505245] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 33.510247] ? kasan_check_read+0x11/0x20 [ 33.514389] ? lock_acquire+0x1e4/0x540 [ 33.518352] ? genl_rcv+0x19/0x40 [ 33.521796] ? radix_tree_lookup+0x21/0x30 [ 33.526025] genl_rcv_msg+0xc6/0x168 [ 33.529743] netlink_rcv_skb+0x172/0x440 [ 33.533786] ? genl_family_rcv_msg+0x1140/0x1140 [ 33.538522] ? netlink_ack+0xbe0/0xbe0 [ 33.542395] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 33.546789] genl_rcv+0x28/0x40 [ 33.550062] netlink_unicast+0x5a0/0x760 [ 33.554129] ? netlink_attachskb+0x9a0/0x9a0 [ 33.558525] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 33.564064] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 33.569082] netlink_sendmsg+0xa18/0xfc0 [ 33.573132] ? netlink_unicast+0x760/0x760 [ 33.577364] ? move_addr_to_kernel.part.18+0x100/0x100 [ 33.582625] ? security_socket_sendmsg+0x94/0xc0 [ 33.587365] ? netlink_unicast+0x760/0x760 [ 33.591590] sock_sendmsg+0xd5/0x120 [ 33.595292] ___sys_sendmsg+0x7fd/0x930 [ 33.599309] ? copy_msghdr_from_user+0x580/0x580 [ 33.604074] ? graph_lock+0x170/0x170 [ 33.607865] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 33.613448] ? __fget_light+0x2f7/0x440 [ 33.617410] ? fget_raw+0x20/0x20 [ 33.620855] ? lock_downgrade+0x8f0/0x8f0 [ 33.625000] ? handle_mm_fault+0x8c4/0xc80 [ 33.629265] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 33.634803] ? sockfd_lookup_light+0xc5/0x160 [ 33.639291] __sys_sendmsg+0x11d/0x290 [ 33.643165] ? __ia32_sys_shutdown+0x80/0x80 [ 33.647630] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 33.653164] ? __do_page_fault+0x449/0xe50 [ 33.657397] __x64_sys_sendmsg+0x78/0xb0 [ 33.661447] do_syscall_64+0x1b9/0x820 [ 33.665320] ? syscall_return_slowpath+0x5e0/0x5e0 [ 33.670232] ? syscall_return_slowpath+0x31d/0x5e0 [ 33.675147] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 33.680722] ? retint_user+0x18/0x18 [ 33.684428] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 33.689253] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 33.694427] RIP: 0033:0x4400e9 [ 33.697598] 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 [ 33.716700] RSP: 002b:00007fffce4de4d8 EFLAGS: 00000213 ORIG_RAX: 000000000000002e [ 33.72452