[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.386979] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 23.224054] random: sshd: uninitialized urandom read (32 bytes read) [ 23.519659] random: sshd: uninitialized urandom read (32 bytes read) [ 24.061512] random: sshd: uninitialized urandom read (32 bytes read) [ 24.239988] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.23' (ECDSA) to the list of known hosts. [ 29.779279] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 29.876137] netlink: 'syz-executor888': attribute type 8 has an invalid length. [ 29.884313] [ 29.885946] ============================================ [ 29.891374] WARNING: possible recursive locking detected [ 29.896801] 4.18.0-rc8+ #179 Not tainted [ 29.900849] -------------------------------------------- [ 29.906282] syz-executor888/4369 is trying to acquire lock: [ 29.911970] (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 29.922809] [ 29.922809] but task is already holding lock: [ 29.928783] (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 29.938340] [ 29.938340] other info that might help us debug this: [ 29.944989] Possible unsafe locking scenario: [ 29.944989] [ 29.951023] CPU0 [ 29.953579] ---- [ 29.956135] lock(&(&tlocks[i])->rlock); [ 29.960263] lock(&(&tlocks[i])->rlock); [ 29.964388] [ 29.964388] *** DEADLOCK *** [ 29.964388] [ 29.970427] May be due to missing lock nesting notation [ 29.970427] [ 29.977337] 3 locks held by syz-executor888/4369: [ 29.982156] #0: (____ptrval____) (cb_lock){++++}, at: genl_rcv+0x19/0x40 [ 29.989076] #1: (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 29.999036] #2: (____ptrval____) (rcu_read_lock){....}, at: rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 30.009690] [ 30.009690] stack backtrace: [ 30.014179] CPU: 0 PID: 4369 Comm: syz-executor888 Not tainted 4.18.0-rc8+ #179 [ 30.021602] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.031101] Call Trace: [ 30.033677] dump_stack+0x1c9/0x2b4 [ 30.037288] ? dump_stack_print_info.cold.2+0x52/0x52 [ 30.042477] ? ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 30.047832] ? vprintk_func+0x81/0xe7 [ 30.051626] __lock_acquire.cold.65+0x1fb/0x486 [ 30.056277] ? __lock_acquire+0x7fc/0x5020 [ 30.060515] ? trace_hardirqs_on+0x10/0x10 [ 30.064740] ? trace_hardirqs_on+0x10/0x10 [ 30.068960] ? __lock_acquire+0x7fc/0x5020 [ 30.073181] ? rcu_is_watching+0x8c/0x150 [ 30.077368] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 30.081767] ? trace_hardirqs_on+0x10/0x10 [ 30.085984] ? __kernel_text_address+0xd/0x40 [ 30.090565] ? unwind_get_return_address+0x61/0xa0 [ 30.095479] ? __save_stack_trace+0x8d/0xf0 [ 30.099912] ? add_lock_to_list.isra.30+0x1ec/0x4b0 [ 30.104911] ? trace_hardirqs_off+0x10/0x10 [ 30.109219] ? save_stack_trace+0x1a/0x20 [ 30.113358] ? save_trace+0xe0/0x290 [ 30.117064] ? kasan_check_read+0x11/0x20 [ 30.121283] ? __lock_acquire+0x28d9/0x5020 [ 30.125601] lock_acquire+0x1e4/0x540 [ 30.129388] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 30.136040] ? rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 30.142770] ? lock_release+0xa30/0xa30 [ 30.146788] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 30.151989] _raw_spin_lock_bh+0x31/0x40 [ 30.156079] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 30.162739] rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 30.169225] ? kasan_check_read+0x11/0x20 [ 30.173357] ? rcu_is_watching+0x8c/0x150 [ 30.177494] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 30.181960] ? rhashtable_replace_fast.isra.20.constprop.24+0xb60/0xb60 [ 30.188708] ? rhashtable_lookup_fast.isra.18.constprop.30+0x5a3/0xa60 [ 30.195416] ? parse_nl_config.isra.13+0x550/0x550 [ 30.200342] ? lock_acquire+0x1e4/0x540 [ 30.204306] ? lock_release+0xa30/0xa30 [ 30.208270] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 30.213800] ? ila_init_saved_csum+0x9b/0x330 [ 30.218296] ? kasan_check_write+0x14/0x20 [ 30.222515] ? do_raw_spin_lock+0xc1/0x200 [ 30.226736] ila_xlat_nl_cmd_add_mapping+0xafe/0x17e0 [ 30.231914] ? wake_up_klogd+0x110/0x110 [ 30.235961] ? __rhashtable_remove_fast.constprop.25+0xe30/0xe30 [ 30.242091] ? mark_held_locks+0xc9/0x160 [ 30.246274] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 30.250851] ? vprintk_default+0x28/0x30 [ 30.254890] ? vprintk_func+0x81/0xe7 [ 30.258669] ? printk+0xa7/0xcf [ 30.261932] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 30.266673] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 30.271845] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 30.276842] ? validate_nla+0x2d9/0x7b0 [ 30.280797] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 30.286316] ? nla_parse+0x32b/0x4e0 [ 30.290017] ? __netlink_ns_capable+0x100/0x130 [ 30.294779] genl_family_rcv_msg+0x8a3/0x1140 [ 30.299259] ? genl_unregister_family+0x8b0/0x8b0 [ 30.304082] ? lock_downgrade+0x8f0/0x8f0 [ 30.308209] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 30.313207] ? kasan_check_read+0x11/0x20 [ 30.317345] ? lock_acquire+0x1e4/0x540 [ 30.321304] ? genl_rcv+0x19/0x40 [ 30.324739] ? radix_tree_lookup+0x21/0x30 [ 30.328969] genl_rcv_msg+0xc6/0x168 [ 30.332665] netlink_rcv_skb+0x172/0x440 [ 30.336713] ? genl_family_rcv_msg+0x1140/0x1140 [ 30.341450] ? netlink_ack+0xbe0/0xbe0 [ 30.345367] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 30.349764] genl_rcv+0x28/0x40 [ 30.353025] netlink_unicast+0x5a0/0x760 [ 30.357070] ? netlink_attachskb+0x9a0/0x9a0 [ 30.361471] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 30.366996] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 30.372003] netlink_sendmsg+0xa18/0xfc0 [ 30.376053] ? netlink_unicast+0x760/0x760 [ 30.380280] ? move_addr_to_kernel.part.18+0x100/0x100 [ 30.385583] ? security_socket_sendmsg+0x94/0xc0 [ 30.390373] ? netlink_unicast+0x760/0x760 [ 30.394601] sock_sendmsg+0xd5/0x120 [ 30.398303] ___sys_sendmsg+0x7fd/0x930 [ 30.402262] ? copy_msghdr_from_user+0x580/0x580 [ 30.407003] ? graph_lock+0x170/0x170 [ 30.410873] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 30.416402] ? __fget_light+0x2f7/0x440 [ 30.420364] ? fget_raw+0x20/0x20 [ 30.423851] ? lock_downgrade+0x8f0/0x8f0 [ 30.427985] ? handle_mm_fault+0x8c4/0xc80 [ 30.432208] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 30.437731] ? sockfd_lookup_light+0xc5/0x160 [ 30.442219] __sys_sendmsg+0x11d/0x290 [ 30.446089] ? __ia32_sys_shutdown+0x80/0x80 [ 30.450485] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 30.456005] ? __do_page_fault+0x449/0xe50 [ 30.460228] __x64_sys_sendmsg+0x78/0xb0 [ 30.464275] do_syscall_64+0x1b9/0x820 [ 30.468154] ? syscall_return_slowpath+0x5e0/0x5e0 [ 30.473070] ? syscall_return_slowpath+0x31d/0x5e0 [ 30.477994] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 30.483526] ? retint_user+0x18/0x18 [ 30.487232] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.492063] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 30.497235] RIP: 0033:0x4400e9 [ 30.500405] 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 [ 30.519550] RSP: 002b:00007ffe5e5e70f8 EFLAGS: 00000213 ORIG_RAX: 000000000000002e [ 30.527260] RAX: