[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.973871] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 22.510950] random: sshd: uninitialized urandom read (32 bytes read) [ 22.900917] random: sshd: uninitialized urandom read (32 bytes read) [ 23.469242] random: sshd: uninitialized urandom read (32 bytes read) [ 23.639145] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.15.205' (ECDSA) to the list of known hosts. [ 29.262237] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 29.354313] [ 29.355965] ============================================ [ 29.361391] WARNING: possible recursive locking detected [ 29.366827] 4.18.0-rc8+ #181 Not tainted [ 29.370859] -------------------------------------------- [ 29.376283] syz-executor280/4397 is trying to acquire lock: [ 29.381967] (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 29.392804] [ 29.392804] but task is already holding lock: [ 29.398763] (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 29.408283] [ 29.408283] other info that might help us debug this: [ 29.414926] Possible unsafe locking scenario: [ 29.414926] [ 29.420969] CPU0 [ 29.423527] ---- [ 29.426091] lock(&(&tlocks[i])->rlock); [ 29.430216] lock(&(&tlocks[i])->rlock); [ 29.434342] [ 29.434342] *** DEADLOCK *** [ 29.434342] [ 29.440376] May be due to missing lock nesting notation [ 29.440376] [ 29.447281] 3 locks held by syz-executor280/4397: [ 29.452097] #0: (____ptrval____) (cb_lock){++++}, at: genl_rcv+0x19/0x40 [ 29.459018] #1: (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 29.468997] #2: (____ptrval____) (rcu_read_lock){....}, at: rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 29.479721] [ 29.479721] stack backtrace: [ 29.484207] CPU: 0 PID: 4397 Comm: syz-executor280 Not tainted 4.18.0-rc8+ #181 [ 29.491633] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.500964] Call Trace: [ 29.503537] dump_stack+0x1c9/0x2b4 [ 29.507146] ? dump_stack_print_info.cold.2+0x52/0x52 [ 29.512331] ? ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 29.517746] ? vprintk_func+0x81/0xe7 [ 29.521533] __lock_acquire.cold.65+0x1fb/0x486 [ 29.526185] ? __lock_acquire+0x7fc/0x5020 [ 29.530430] ? trace_hardirqs_on+0x10/0x10 [ 29.534659] ? trace_hardirqs_on+0x10/0x10 [ 29.538877] ? __lock_acquire+0x7fc/0x5020 [ 29.543093] ? rcu_is_watching+0x8c/0x150 [ 29.547269] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 29.551675] ? trace_hardirqs_on+0x10/0x10 [ 29.555896] ? __kernel_text_address+0xd/0x40 [ 29.560377] ? unwind_get_return_address+0x61/0xa0 [ 29.565291] ? __save_stack_trace+0x8d/0xf0 [ 29.569598] ? add_lock_to_list.isra.30+0x1ec/0x4b0 [ 29.574596] ? trace_hardirqs_off+0x10/0x10 [ 29.578903] ? save_stack_trace+0x1a/0x20 [ 29.583052] ? save_trace+0xe0/0x290 [ 29.586756] ? kasan_check_read+0x11/0x20 [ 29.590939] ? __lock_acquire+0x28d9/0x5020 [ 29.595255] lock_acquire+0x1e4/0x540 [ 29.599048] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 29.605702] ? rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 29.612351] ? lock_release+0xa30/0xa30 [ 29.616307] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 29.621479] _raw_spin_lock_bh+0x31/0x40 [ 29.625525] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 29.632179] rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 29.638659] ? kasan_check_read+0x11/0x20 [ 29.642788] ? rcu_is_watching+0x8c/0x150 [ 29.646917] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 29.651314] ? rhashtable_replace_fast.isra.20.constprop.24+0xb60/0xb60 [ 29.658057] ? rhashtable_lookup_fast.isra.18.constprop.30+0x5a3/0xa60 [ 29.664709] ? parse_nl_config.isra.13+0x550/0x550 [ 29.669621] ? lock_acquire+0x1e4/0x540 [ 29.673577] ? lock_release+0xa30/0xa30 [ 29.677534] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 29.683053] ? ila_init_saved_csum+0x9b/0x330 [ 29.687545] ? kasan_check_write+0x14/0x20 [ 29.691761] ? do_raw_spin_lock+0xc1/0x200 [ 29.695982] ila_xlat_nl_cmd_add_mapping+0xafe/0x17e0 [ 29.701162] ? depot_save_stack+0x291/0x470 [ 29.705470] ? __rhashtable_remove_fast.constprop.25+0xe30/0xe30 [ 29.711594] ? __kmalloc+0x14e/0x760 [ 29.715284] ? genl_rcv_msg+0xc6/0x168 [ 29.719147] ? netlink_rcv_skb+0x172/0x440 [ 29.723356] ? genl_rcv+0x28/0x40 [ 29.726841] ? netlink_unicast+0x5a0/0x760 [ 29.731065] ? netlink_sendmsg+0xa18/0xfc0 [ 29.735283] ? sock_sendmsg+0xd5/0x120 [ 29.739156] ? ___sys_sendmsg+0x7fd/0x930 [ 29.743283] ? __sys_sendmsg+0x11d/0x290 [ 29.747324] ? __x64_sys_sendmsg+0x78/0xb0 [ 29.751558] ? do_syscall_64+0x1b9/0x820 [ 29.755671] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 29.761035] ? find_held_lock+0x36/0x1c0 [ 29.765094] ? print_usage_bug+0xc0/0xc0 [ 29.769141] ? graph_lock+0x170/0x170 [ 29.772922] ? __lock_is_held+0xb5/0x140 [ 29.776974] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 29.782150] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 29.787214] ? validate_nla+0x2d9/0x7b0 [ 29.791177] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.796719] ? nla_parse+0x32b/0x4e0 [ 29.800436] ? __netlink_ns_capable+0x100/0x130 [ 29.805090] genl_family_rcv_msg+0x8a3/0x1140 [ 29.809588] ? genl_unregister_family+0x8b0/0x8b0 [ 29.814540] ? lock_downgrade+0x8f0/0x8f0 [ 29.818671] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 29.823670] ? kasan_check_read+0x11/0x20 [ 29.827798] ? lock_acquire+0x1e4/0x540 [ 29.831759] ? genl_rcv+0x19/0x40 [ 29.835197] ? radix_tree_lookup+0x21/0x30 [ 29.839415] genl_rcv_msg+0xc6/0x168 [ 29.843112] netlink_rcv_skb+0x172/0x440 [ 29.847195] ? genl_family_rcv_msg+0x1140/0x1140 [ 29.851946] ? netlink_ack+0xbe0/0xbe0 [ 29.855818] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 29.860209] genl_rcv+0x28/0x40 [ 29.863470] netlink_unicast+0x5a0/0x760 [ 29.867515] ? netlink_attachskb+0x9a0/0x9a0 [ 29.871905] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.877421] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 29.882418] netlink_sendmsg+0xa18/0xfc0 [ 29.886461] ? netlink_unicast+0x760/0x760 [ 29.890681] ? move_addr_to_kernel.part.18+0x100/0x100 [ 29.895949] ? security_socket_sendmsg+0x94/0xc0 [ 29.900687] ? netlink_unicast+0x760/0x760 [ 29.904903] sock_sendmsg+0xd5/0x120 [ 29.908599] ___sys_sendmsg+0x7fd/0x930 [ 29.912556] ? copy_msghdr_from_user+0x580/0x580 [ 29.917292] ? graph_lock+0x170/0x170 [ 29.921083] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.926600] ? __fget_light+0x2f7/0x440 [ 29.930557] ? fget_raw+0x20/0x20 [ 29.933994] ? lock_downgrade+0x8f0/0x8f0 [ 29.938128] ? handle_mm_fault+0x8c4/0xc80 [ 29.942344] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 29.947865] ? sockfd_lookup_light+0xc5/0x160 [ 29.952342] __sys_sendmsg+0x11d/0x290 [ 29.956212] ? __ia32_sys_shutdown+0x80/0x80 [ 29.960603] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.966122] ? __do_page_fault+0x449/0xe50 [ 29.970343] __x64_sys_sendmsg+0x78/0xb0 [ 29.974385] do_syscall_64+0x1b9/0x820 [ 29.978277] ? syscall_slow_exit_work+0x500/0x500 [ 29.983100] ? syscall_return_slowpath+0x5e0/0x5e0 [ 29.988023] ? syscall_return_slowpath+0x31d/0x5e0 [ 29.992972] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.998489] ? retint_user+0x18/0x18 [ 30.002195] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.007029] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 30.012210] RIP: 0033:0x4400e9 [ 30.015377] 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 [ 30.034468] RSP: 002b:00007ffcbf8c80c8 EFLAGS: 00000213 ORIG_RAX: 000000000000002e [ 30.042156] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004400e9 [ 30.049403] RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000003 [ 30.05