[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 21.017355] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 24.221527] random: sshd: uninitialized urandom read (32 bytes read) [ 24.556579] random: sshd: uninitialized urandom read (32 bytes read) [ 25.075996] random: sshd: uninitialized urandom read (32 bytes read) [ 25.247419] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.20' (ECDSA) to the list of known hosts. [ 30.773744] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 30.866384] netlink: 'syz-executor132': attribute type 8 has an invalid length. [ 30.874574] [ 30.876209] ============================================ [ 30.881633] WARNING: possible recursive locking detected [ 30.887076] 4.18.0-rc8+ #179 Not tainted [ 30.891114] -------------------------------------------- [ 30.896557] syz-executor132/4436 is trying to acquire lock: [ 30.902243] (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 30.913087] [ 30.913087] but task is already holding lock: [ 30.919050] (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 30.928591] [ 30.928591] other info that might help us debug this: [ 30.935237] Possible unsafe locking scenario: [ 30.935237] [ 30.941274] CPU0 [ 30.943833] ---- [ 30.946391] lock(&(&tlocks[i])->rlock); [ 30.950527] lock(&(&tlocks[i])->rlock); [ 30.954663] [ 30.954663] *** DEADLOCK *** [ 30.954663] [ 30.960705] May be due to missing lock nesting notation [ 30.960705] [ 30.967613] 3 locks held by syz-executor132/4436: [ 30.972430] #0: (____ptrval____) (cb_lock){++++}, at: genl_rcv+0x19/0x40 [ 30.979618] #1: (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 30.989596] #2: (____ptrval____) (rcu_read_lock){....}, at: rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 31.000263] [ 31.000263] stack backtrace: [ 31.004742] CPU: 1 PID: 4436 Comm: syz-executor132 Not tainted 4.18.0-rc8+ #179 [ 31.012168] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.021499] Call Trace: [ 31.024074] dump_stack+0x1c9/0x2b4 [ 31.027688] ? dump_stack_print_info.cold.2+0x52/0x52 [ 31.032862] ? ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 31.038211] ? vprintk_func+0x81/0xe7 [ 31.041997] __lock_acquire.cold.65+0x1fb/0x486 [ 31.046667] ? __lock_acquire+0x7fc/0x5020 [ 31.050890] ? trace_hardirqs_on+0x10/0x10 [ 31.055107] ? trace_hardirqs_on+0x10/0x10 [ 31.059325] ? __lock_acquire+0x7fc/0x5020 [ 31.063555] ? rcu_is_watching+0x8c/0x150 [ 31.067701] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 31.072099] ? trace_hardirqs_on+0x10/0x10 [ 31.076326] ? __kernel_text_address+0xd/0x40 [ 31.080810] ? unwind_get_return_address+0x61/0xa0 [ 31.085726] ? __save_stack_trace+0x8d/0xf0 [ 31.090033] ? add_lock_to_list.isra.30+0x1ec/0x4b0 [ 31.095102] ? trace_hardirqs_off+0x10/0x10 [ 31.099415] ? save_stack_trace+0x1a/0x20 [ 31.103546] ? save_trace+0xe0/0x290 [ 31.107247] ? kasan_check_read+0x11/0x20 [ 31.111377] ? __lock_acquire+0x28d9/0x5020 [ 31.115684] lock_acquire+0x1e4/0x540 [ 31.119472] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 31.126121] ? rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 31.132770] ? lock_release+0xa30/0xa30 [ 31.136734] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 31.141912] _raw_spin_lock_bh+0x31/0x40 [ 31.145961] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 31.152609] rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 31.159090] ? kasan_check_read+0x11/0x20 [ 31.163221] ? rcu_is_watching+0x8c/0x150 [ 31.167361] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 31.171757] ? rhashtable_replace_fast.isra.20.constprop.24+0xb60/0xb60 [ 31.178493] ? rhashtable_lookup_fast.isra.18.constprop.30+0x5a3/0xa60 [ 31.185152] ? parse_nl_config.isra.13+0x550/0x550 [ 31.190077] ? lock_acquire+0x1e4/0x540 [ 31.194037] ? lock_release+0xa30/0xa30 [ 31.198002] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 31.203518] ? ila_init_saved_csum+0x9b/0x330 [ 31.207999] ? kasan_check_write+0x14/0x20 [ 31.212219] ? do_raw_spin_lock+0xc1/0x200 [ 31.216435] ila_xlat_nl_cmd_add_mapping+0xafe/0x17e0 [ 31.221612] ? wake_up_klogd+0x110/0x110 [ 31.225663] ? __rhashtable_remove_fast.constprop.25+0xe30/0xe30 [ 31.231793] ? mark_held_locks+0xc9/0x160 [ 31.235923] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 31.240487] ? vprintk_default+0x28/0x30 [ 31.244527] ? vprintk_func+0x81/0xe7 [ 31.248310] ? printk+0xa7/0xcf [ 31.251576] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 31.256317] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 31.261496] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 31.266494] ? validate_nla+0x2d9/0x7b0 [ 31.270453] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 31.275975] ? nla_parse+0x32b/0x4e0 [ 31.279769] ? __netlink_ns_capable+0x100/0x130 [ 31.284425] genl_family_rcv_msg+0x8a3/0x1140 [ 31.288908] ? genl_unregister_family+0x8b0/0x8b0 [ 31.293735] ? lock_downgrade+0x8f0/0x8f0 [ 31.297866] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 31.302868] ? kasan_check_read+0x11/0x20 [ 31.306998] ? lock_acquire+0x1e4/0x540 [ 31.310952] ? genl_rcv+0x19/0x40 [ 31.314441] ? radix_tree_lookup+0x21/0x30 [ 31.318698] genl_rcv_msg+0xc6/0x168 [ 31.322399] netlink_rcv_skb+0x172/0x440 [ 31.326449] ? genl_family_rcv_msg+0x1140/0x1140 [ 31.331191] ? netlink_ack+0xbe0/0xbe0 [ 31.335057] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 31.339445] genl_rcv+0x28/0x40 [ 31.342706] netlink_unicast+0x5a0/0x760 [ 31.346751] ? netlink_attachskb+0x9a0/0x9a0 [ 31.351144] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 31.356677] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 31.361679] netlink_sendmsg+0xa18/0xfc0 [ 31.365788] ? netlink_unicast+0x760/0x760 [ 31.370016] ? move_addr_to_kernel.part.18+0x100/0x100 [ 31.375277] ? security_socket_sendmsg+0x94/0xc0 [ 31.380011] ? netlink_unicast+0x760/0x760 [ 31.384227] sock_sendmsg+0xd5/0x120 [ 31.387929] ___sys_sendmsg+0x7fd/0x930 [ 31.391884] ? copy_msghdr_from_user+0x580/0x580 [ 31.396623] ? graph_lock+0x170/0x170 [ 31.400413] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 31.405935] ? __fget_light+0x2f7/0x440 [ 31.409892] ? fget_raw+0x20/0x20 [ 31.413327] ? lock_downgrade+0x8f0/0x8f0 [ 31.417456] ? handle_mm_fault+0x8c4/0xc80 [ 31.421675] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 31.427195] ? sockfd_lookup_light+0xc5/0x160 [ 31.431669] __sys_sendmsg+0x11d/0x290 [ 31.435556] ? __ia32_sys_shutdown+0x80/0x80 [ 31.439967] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 31.445485] ? __do_page_fault+0x449/0xe50 [ 31.449703] __x64_sys_sendmsg+0x78/0xb0 [ 31.453745] do_syscall_64+0x1b9/0x820 [ 31.457609] ? syscall_return_slowpath+0x5e0/0x5e0 [ 31.462519] ? syscall_return_slowpath+0x31d/0x5e0 [ 31.467433] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 31.472951] ? retint_user+0x18/0x18 [ 31.476651] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 31.481474] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 31.486650] RIP: 0033:0x4400e9 [ 31.489822] 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 [ 31.508922] RSP: 002b:00007ffd1657d5a8 EFLAGS: 00000213 ORIG_RAX: 000000000000002e [ 31.516613] RAX: fffffffffff