[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 21.307149] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 24.848140] random: sshd: uninitialized urandom read (32 bytes read) [ 25.253460] random: sshd: uninitialized urandom read (32 bytes read) [ 25.781773] random: sshd: uninitialized urandom read (32 bytes read) [ 25.955598] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.44' (ECDSA) to the list of known hosts. [ 31.461502] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 31.555218] [ 31.556861] ============================================ [ 31.562537] WARNING: possible recursive locking detected [ 31.567968] 4.18.0-rc8+ #179 Not tainted [ 31.572155] -------------------------------------------- [ 31.577705] syz-executor386/4407 is trying to acquire lock: [ 31.583420] (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 31.594371] [ 31.594371] but task is already holding lock: [ 31.600318] (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 31.609851] [ 31.609851] other info that might help us debug this: [ 31.616494] Possible unsafe locking scenario: [ 31.616494] [ 31.622526] CPU0 [ 31.625197] ---- [ 31.627759] lock(&(&tlocks[i])->rlock); [ 31.631884] lock(&(&tlocks[i])->rlock); [ 31.636028] [ 31.636028] *** DEADLOCK *** [ 31.636028] [ 31.642061] May be due to missing lock nesting notation [ 31.642061] [ 31.648980] 3 locks held by syz-executor386/4407: [ 31.653794] #0: (____ptrval____) (cb_lock){++++}, at: genl_rcv+0x19/0x40 [ 31.660713] #1: (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 31.670672] #2: (____ptrval____) (rcu_read_lock){....}, at: rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 31.681324] [ 31.681324] stack backtrace: [ 31.685802] CPU: 0 PID: 4407 Comm: syz-executor386 Not tainted 4.18.0-rc8+ #179 [ 31.693229] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.702558] Call Trace: [ 31.705133] dump_stack+0x1c9/0x2b4 [ 31.708742] ? dump_stack_print_info.cold.2+0x52/0x52 [ 31.713913] ? ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 31.719363] ? vprintk_func+0x81/0xe7 [ 31.723185] __lock_acquire.cold.65+0x1fb/0x486 [ 31.727838] ? __lock_acquire+0x7fc/0x5020 [ 31.732053] ? trace_hardirqs_on+0x10/0x10 [ 31.736267] ? trace_hardirqs_on+0x10/0x10 [ 31.740480] ? __lock_acquire+0x7fc/0x5020 [ 31.744695] ? rcu_is_watching+0x8c/0x150 [ 31.748825] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 31.753218] ? trace_hardirqs_on+0x10/0x10 [ 31.757434] ? __kernel_text_address+0xd/0x40 [ 31.761909] ? unwind_get_return_address+0x61/0xa0 [ 31.766852] ? __save_stack_trace+0x8d/0xf0 [ 31.771176] ? add_lock_to_list.isra.30+0x1ec/0x4b0 [ 31.776237] ? trace_hardirqs_off+0x10/0x10 [ 31.780662] ? save_stack_trace+0x1a/0x20 [ 31.784789] ? save_trace+0xe0/0x290 [ 31.788491] ? kasan_check_read+0x11/0x20 [ 31.792632] ? __lock_acquire+0x28d9/0x5020 [ 31.796935] lock_acquire+0x1e4/0x540 [ 31.800715] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 31.807375] ? rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 31.814027] ? lock_release+0xa30/0xa30 [ 31.818087] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 31.823261] _raw_spin_lock_bh+0x31/0x40 [ 31.827319] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 31.833967] rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 31.840542] ? kasan_check_read+0x11/0x20 [ 31.844671] ? rcu_is_watching+0x8c/0x150 [ 31.848922] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 31.853346] ? rhashtable_replace_fast.isra.20.constprop.24+0xb60/0xb60 [ 31.860080] ? rhashtable_lookup_fast.isra.18.constprop.30+0x5a3/0xa60 [ 31.866845] ? parse_nl_config.isra.13+0x550/0x550 [ 31.871894] ? lock_acquire+0x1e4/0x540 [ 31.875983] ? do_csum+0x345/0x410 [ 31.879508] ? lock_release+0xa30/0xa30 [ 31.883460] ? csum_partial+0x21/0x30 [ 31.887447] ? ila_init_saved_csum+0x9b/0x330 [ 31.892035] ? kasan_check_write+0x14/0x20 [ 31.896251] ? do_raw_spin_lock+0xc1/0x200 [ 31.900467] ila_xlat_nl_cmd_add_mapping+0xafe/0x17e0 [ 31.905637] ? depot_save_stack+0x291/0x470 [ 31.909941] ? __rhashtable_remove_fast.constprop.25+0xe30/0xe30 [ 31.916144] ? __kmalloc+0x14e/0x760 [ 31.919856] ? genl_rcv_msg+0xc6/0x168 [ 31.923723] ? netlink_rcv_skb+0x172/0x440 [ 31.927935] ? genl_rcv+0x28/0x40 [ 31.931369] ? netlink_unicast+0x5a0/0x760 [ 31.935582] ? netlink_sendmsg+0xa18/0xfc0 [ 31.939797] ? sock_sendmsg+0xd5/0x120 [ 31.943664] ? ___sys_sendmsg+0x7fd/0x930 [ 31.947789] ? __sys_sendmsg+0x11d/0x290 [ 31.951826] ? __x64_sys_sendmsg+0x78/0xb0 [ 31.956039] ? do_syscall_64+0x1b9/0x820 [ 31.960085] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 31.965429] ? find_held_lock+0x36/0x1c0 [ 31.969471] ? print_usage_bug+0xc0/0xc0 [ 31.973509] ? graph_lock+0x170/0x170 [ 31.977356] ? __lock_is_held+0xb5/0x140 [ 31.981406] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 31.986579] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 31.991711] ? validate_nla+0x2d9/0x7b0 [ 31.995668] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 32.001183] ? nla_parse+0x32b/0x4e0 [ 32.004877] ? __netlink_ns_capable+0x100/0x130 [ 32.009658] genl_family_rcv_msg+0x8a3/0x1140 [ 32.014137] ? genl_unregister_family+0x8b0/0x8b0 [ 32.018961] ? lock_downgrade+0x8f0/0x8f0 [ 32.023092] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 32.028092] ? kasan_check_read+0x11/0x20 [ 32.032219] ? lock_acquire+0x1e4/0x540 [ 32.036170] ? genl_rcv+0x19/0x40 [ 32.039602] ? radix_tree_lookup+0x21/0x30 [ 32.043816] genl_rcv_msg+0xc6/0x168 [ 32.047544] netlink_rcv_skb+0x172/0x440 [ 32.051594] ? genl_family_rcv_msg+0x1140/0x1140 [ 32.056334] ? netlink_ack+0xbe0/0xbe0 [ 32.060201] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 32.064590] genl_rcv+0x28/0x40 [ 32.067950] netlink_unicast+0x5a0/0x760 [ 32.071994] ? netlink_attachskb+0x9a0/0x9a0 [ 32.076388] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 32.081903] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 32.086896] netlink_sendmsg+0xa18/0xfc0 [ 32.090936] ? netlink_unicast+0x760/0x760 [ 32.095152] ? move_addr_to_kernel.part.18+0x100/0x100 [ 32.100412] ? security_socket_sendmsg+0x94/0xc0 [ 32.105148] ? netlink_unicast+0x760/0x760 [ 32.109363] sock_sendmsg+0xd5/0x120 [ 32.113056] ___sys_sendmsg+0x7fd/0x930 [ 32.117027] ? copy_msghdr_from_user+0x580/0x580 [ 32.121779] ? graph_lock+0x170/0x170 [ 32.125671] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 32.131191] ? __fget_light+0x2f7/0x440 [ 32.135147] ? fget_raw+0x20/0x20 [ 32.138610] ? lock_downgrade+0x8f0/0x8f0 [ 32.142744] ? handle_mm_fault+0x8c4/0xc80 [ 32.147077] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 32.152608] ? sockfd_lookup_light+0xc5/0x160 [ 32.157233] __sys_sendmsg+0x11d/0x290 [ 32.161101] ? __ia32_sys_shutdown+0x80/0x80 [ 32.165490] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 32.171037] ? __do_page_fault+0x449/0xe50 [ 32.175264] __x64_sys_sendmsg+0x78/0xb0 [ 32.179410] do_syscall_64+0x1b9/0x820 [ 32.183384] ? syscall_slow_exit_work+0x500/0x500 [ 32.188238] ? syscall_return_slowpath+0x5e0/0x5e0 [ 32.193197] ? syscall_return_slowpath+0x31d/0x5e0 [ 32.198111] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 32.203776] ? retint_user+0x18/0x18 [ 32.207478] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 32.212311] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 32.217566] RIP: 0033:0x4400f9 [ 32.220753] 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 [ 32.239842] RSP: 002b:00007ffe3900ddc8 EFLAGS: 00000213 ORIG_RAX: 000000000000002e [ 32.247562] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004400f9 [ 32.254813] RDX: 0000000000000000 RSI