[....] Starting OpenBSD Secure Shell server: sshd[ 23.046787] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. [ 23.276258] random: sshd: uninitialized urandom read (32 bytes read) [ 23.556279] random: sshd: uninitialized urandom read (32 bytes read) [ 24.084943] random: sshd: uninitialized urandom read (32 bytes read) [ 24.263294] random: sshd: uninitialized urandom read (32 bytes read) Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.48' (ECDSA) to the list of known hosts. syzkaller login: [ 29.904480] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 30.001380] [ 30.003032] ============================================ [ 30.008471] WARNING: possible recursive locking detected [ 30.014014] 4.18.0-rc8-next-20180810+ #36 Not tainted [ 30.019193] -------------------------------------------- [ 30.024640] syz-executor851/4447 is trying to acquire lock: [ 30.030349] 000000006ff9ba1c (&(&tlocks[i])->rlock){+.+.}, at: rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 30.041262] [ 30.041262] but task is already holding lock: [ 30.047225] 000000009932107b (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 30.056784] [ 30.056784] other info that might help us debug this: [ 30.063437] Possible unsafe locking scenario: [ 30.063437] [ 30.069484] CPU0 [ 30.072062] ---- [ 30.074633] lock(&(&tlocks[i])->rlock); [ 30.078868] lock(&(&tlocks[i])->rlock); [ 30.083018] [ 30.083018] *** DEADLOCK *** [ 30.083018] [ 30.089137] May be due to missing lock nesting notation [ 30.089137] [ 30.096059] 3 locks held by syz-executor851/4447: [ 30.100889] #0: 00000000d4ad32b5 (cb_lock){++++}, at: genl_rcv+0x19/0x40 [ 30.108032] #1: 000000009932107b (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 30.118021] #2: 000000002cf8ccf6 (rcu_read_lock){....}, at: rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 30.128686] [ 30.128686] stack backtrace: [ 30.133185] CPU: 1 PID: 4447 Comm: syz-executor851 Not tainted 4.18.0-rc8-next-20180810+ #36 [ 30.141747] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.151093] Call Trace: [ 30.153682] dump_stack+0x1c9/0x2b4 [ 30.157306] ? dump_stack_print_info.cold.2+0x52/0x52 [ 30.162568] ? ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 30.167935] ? vprintk_func+0x81/0x117 [ 30.171816] __lock_acquire.cold.65+0x1fb/0x486 [ 30.176559] ? __lock_acquire+0x7fc/0x5020 [ 30.180934] ? trace_hardirqs_on+0x10/0x10 [ 30.185164] ? trace_hardirqs_on+0x10/0x10 [ 30.189390] ? __lock_acquire+0x7fc/0x5020 [ 30.193629] ? rcu_is_watching+0x8c/0x150 [ 30.197785] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 30.202453] ? trace_hardirqs_on+0x10/0x10 [ 30.206688] ? __kernel_text_address+0xd/0x40 [ 30.211181] ? unwind_get_return_address+0x61/0xa0 [ 30.216106] ? __save_stack_trace+0x8d/0xf0 [ 30.220476] ? add_lock_to_list.isra.30+0x1ec/0x4b0 [ 30.225493] ? trace_hardirqs_off+0x10/0x10 [ 30.229812] ? save_stack_trace+0x1a/0x20 [ 30.233953] ? save_trace+0xe0/0x290 [ 30.237686] ? kasan_check_read+0x11/0x20 [ 30.241828] ? __lock_acquire+0x28d9/0x5020 [ 30.246147] lock_acquire+0x1e4/0x540 [ 30.249944] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 30.256676] ? rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 30.263343] ? lock_release+0xa30/0xa30 [ 30.267376] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 30.272564] _raw_spin_lock_bh+0x31/0x40 [ 30.276640] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 30.283366] rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 30.289913] ? kasan_check_read+0x11/0x20 [ 30.294064] ? rcu_is_watching+0x8c/0x150 [ 30.298203] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 30.303018] ? rhashtable_replace_fast.isra.20.constprop.24+0xb60/0xb60 [ 30.309827] ? rhashtable_lookup_fast.isra.18.constprop.30+0x5a3/0xa60 [ 30.316491] ? parse_nl_config.isra.13+0x550/0x550 [ 30.321416] ? lock_acquire+0x1e4/0x540 [ 30.325435] ? lock_release+0xa30/0xa30 [ 30.329407] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 30.334937] ? ila_init_saved_csum+0x9b/0x330 [ 30.339425] ? kasan_check_write+0x14/0x20 [ 30.343660] ? do_raw_spin_lock+0xc1/0x200 [ 30.347896] ila_xlat_nl_cmd_add_mapping+0xafe/0x17e0 [ 30.353083] ? depot_save_stack+0x291/0x470 [ 30.357401] ? __rhashtable_remove_fast.constprop.25+0xe30/0xe30 [ 30.363600] ? __kmalloc+0x14e/0x760 [ 30.367369] ? genl_rcv_msg+0xc6/0x168 [ 30.371251] ? netlink_rcv_skb+0x172/0x440 [ 30.375751] ? genl_rcv+0x28/0x40 [ 30.379199] ? netlink_unicast+0x5a0/0x760 [ 30.383432] ? netlink_sendmsg+0xa18/0xfc0 [ 30.387668] ? sock_sendmsg+0xd5/0x120 [ 30.391552] ? ___sys_sendmsg+0x7fd/0x930 [ 30.395702] ? __sys_sendmsg+0x11d/0x290 [ 30.399754] ? __x64_sys_sendmsg+0x78/0xb0 [ 30.404006] ? do_syscall_64+0x1b9/0x820 [ 30.408115] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 30.413475] ? find_held_lock+0x36/0x1c0 [ 30.417531] ? print_usage_bug+0xc0/0xc0 [ 30.421591] ? graph_lock+0x170/0x170 [ 30.425397] ? __lock_is_held+0xb5/0x140 [ 30.429455] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 30.434707] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 30.439808] ? validate_nla+0x2d9/0x7b0 [ 30.443779] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 30.449309] ? nla_parse+0x32b/0x4e0 [ 30.453030] ? __netlink_ns_capable+0x100/0x130 [ 30.457693] genl_family_rcv_msg+0x8a3/0x1140 [ 30.462201] ? genl_unregister_family+0x8b0/0x8b0 [ 30.467036] ? lock_downgrade+0x8f0/0x8f0 [ 30.471178] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 30.476455] ? kasan_check_read+0x11/0x20 [ 30.480604] ? lock_acquire+0x1e4/0x540 [ 30.484586] ? genl_rcv+0x19/0x40 [ 30.488131] ? radix_tree_lookup+0x21/0x30 [ 30.492416] genl_rcv_msg+0xc6/0x168 [ 30.496211] netlink_rcv_skb+0x172/0x440 [ 30.500267] ? genl_family_rcv_msg+0x1140/0x1140 [ 30.505028] ? netlink_ack+0xbe0/0xbe0 [ 30.509000] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 30.513675] genl_rcv+0x28/0x40 [ 30.516956] netlink_unicast+0x5a0/0x760 [ 30.521099] ? netlink_attachskb+0x9a0/0x9a0 [ 30.525507] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 30.531040] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 30.536052] netlink_sendmsg+0xa18/0xfc0 [ 30.540195] ? netlink_unicast+0x760/0x760 [ 30.544426] ? move_addr_to_kernel.part.18+0x100/0x100 [ 30.549755] ? security_socket_sendmsg+0x94/0xc0 [ 30.554509] ? netlink_unicast+0x760/0x760 [ 30.558739] sock_sendmsg+0xd5/0x120 [ 30.562448] ___sys_sendmsg+0x7fd/0x930 [ 30.566416] ? copy_msghdr_from_user+0x580/0x580 [ 30.571165] ? graph_lock+0x170/0x170 [ 30.574964] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 30.580522] ? __fget_light+0x2f7/0x440 [ 30.584491] ? fget_raw+0x20/0x20 [ 30.587946] ? lock_downgrade+0x8f0/0x8f0 [ 30.592087] ? handle_mm_fault+0x8c4/0xc80 [ 30.596377] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 30.601968] ? sockfd_lookup_light+0xc5/0x160 [ 30.606608] __sys_sendmsg+0x11d/0x290 [ 30.610507] ? __ia32_sys_shutdown+0x80/0x80 [ 30.614910] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 30.620509] ? __do_page_fault+0x449/0xe50 [ 30.624742] __x64_sys_sendmsg+0x78/0xb0 [ 30.628856] do_syscall_64+0x1b9/0x820 [ 30.632739] ? syscall_slow_exit_work+0x500/0x500 [ 30.637574] ? syscall_return_slowpath+0x5e0/0x5e0 [ 30.642810] ? syscall_return_slowpath+0x31d/0x5e0 [ 30.647738] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 30.653271] ? retint_user+0x18/0x18 [ 30.657004] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.661896] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 30.667076] RIP: 0033:0x4400e9 [ 30.670264] 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 [ 30.689159] RSP: 002b:00007ffed8b00968 EFLAGS: 00000213 ORIG_RAX: 000000000000002e [ 30.696859] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004400e9 [ 30