[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 21.787216] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 27.498493] random: sshd: uninitialized urandom read (32 bytes read) [ 27.886267] random: sshd: uninitialized urandom read (32 bytes read) [ 28.409458] random: sshd: uninitialized urandom read (32 bytes read) [ 28.581554] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.48' (ECDSA) to the list of known hosts. [ 34.180617] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 34.274258] netlink: 'syz-executor238': attribute type 4 has an invalid length. [ 34.282630] [ 34.284276] ============================================ [ 34.289854] WARNING: possible recursive locking detected [ 34.295290] 4.18.0-rc8+ #179 Not tainted [ 34.299331] -------------------------------------------- [ 34.304762] syz-executor238/4458 is trying to acquire lock: [ 34.310460] (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 34.321288] [ 34.321288] but task is already holding lock: [ 34.327239] (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 34.336763] [ 34.336763] other info that might help us debug this: [ 34.343579] Possible unsafe locking scenario: [ 34.343579] [ 34.349616] CPU0 [ 34.352177] ---- [ 34.354736] lock(&(&tlocks[i])->rlock); [ 34.358939] lock(&(&tlocks[i])->rlock); [ 34.363069] [ 34.363069] *** DEADLOCK *** [ 34.363069] [ 34.369107] May be due to missing lock nesting notation [ 34.369107] [ 34.376018] 3 locks held by syz-executor238/4458: [ 34.380845] #0: (____ptrval____) (cb_lock){++++}, at: genl_rcv+0x19/0x40 [ 34.387768] #1: (____ptrval____) (&(&tlocks[i])->rlock){+.+.}, at: ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 34.397742] #2: (____ptrval____) (rcu_read_lock){....}, at: rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 34.408465] [ 34.408465] stack backtrace: [ 34.412955] CPU: 0 PID: 4458 Comm: syz-executor238 Not tainted 4.18.0-rc8+ #179 [ 34.420455] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.429795] Call Trace: [ 34.432410] dump_stack+0x1c9/0x2b4 [ 34.436052] ? dump_stack_print_info.cold.2+0x52/0x52 [ 34.441312] ? ila_xlat_nl_cmd_add_mapping+0x6bb/0x17e0 [ 34.446666] ? vprintk_func+0x81/0xe7 [ 34.450458] __lock_acquire.cold.65+0x1fb/0x486 [ 34.455113] ? __lock_acquire+0x7fc/0x5020 [ 34.459334] ? trace_hardirqs_on+0x10/0x10 [ 34.463558] ? trace_hardirqs_on+0x10/0x10 [ 34.467837] ? __lock_acquire+0x7fc/0x5020 [ 34.472067] ? rcu_is_watching+0x8c/0x150 [ 34.476199] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 34.480604] ? trace_hardirqs_on+0x10/0x10 [ 34.484841] ? __kernel_text_address+0xd/0x40 [ 34.489320] ? unwind_get_return_address+0x61/0xa0 [ 34.494232] ? __save_stack_trace+0x8d/0xf0 [ 34.498550] ? add_lock_to_list.isra.30+0x1ec/0x4b0 [ 34.503548] ? trace_hardirqs_off+0x10/0x10 [ 34.507857] ? save_stack_trace+0x1a/0x20 [ 34.511990] ? save_trace+0xe0/0x290 [ 34.515702] ? kasan_check_read+0x11/0x20 [ 34.519832] ? __lock_acquire+0x28d9/0x5020 [ 34.524141] lock_acquire+0x1e4/0x540 [ 34.527967] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 34.534766] ? rhashtable_lookup_insert_fast.constprop.26+0x1d7/0x13a0 [ 34.541417] ? lock_release+0xa30/0xa30 [ 34.545376] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 34.550722] _raw_spin_lock_bh+0x31/0x40 [ 34.554868] ? rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 34.561635] rhashtable_lookup_insert_fast.constprop.26+0x436/0x13a0 [ 34.568114] ? kasan_check_read+0x11/0x20 [ 34.572244] ? rcu_is_watching+0x8c/0x150 [ 34.576373] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 34.580767] ? rhashtable_replace_fast.isra.20.constprop.24+0xb60/0xb60 [ 34.587503] ? rhashtable_lookup_fast.isra.18.constprop.30+0x5a3/0xa60 [ 34.594248] ? parse_nl_config.isra.13+0x550/0x550 [ 34.599166] ? lock_acquire+0x1e4/0x540 [ 34.603125] ? lock_release+0xa30/0xa30 [ 34.607109] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 34.612687] ? ila_init_saved_csum+0x9b/0x330 [ 34.617235] ? kasan_check_write+0x14/0x20 [ 34.621457] ? do_raw_spin_lock+0xc1/0x200 [ 34.625686] ila_xlat_nl_cmd_add_mapping+0xafe/0x17e0 [ 34.630880] ? wake_up_klogd+0x110/0x110 [ 34.634931] ? __rhashtable_remove_fast.constprop.25+0xe30/0xe30 [ 34.641070] ? mark_held_locks+0xc9/0x160 [ 34.645203] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 34.649827] ? vprintk_default+0x28/0x30 [ 34.653999] ? vprintk_func+0x81/0xe7 [ 34.657856] ? printk+0xa7/0xcf [ 34.661126] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 34.665888] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 34.671072] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 34.676084] ? validate_nla+0x2d9/0x7b0 [ 34.680052] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 34.685579] ? nla_parse+0x32b/0x4e0 [ 34.689287] ? __netlink_ns_capable+0x100/0x130 [ 34.693941] genl_family_rcv_msg+0x8a3/0x1140 [ 34.698425] ? genl_unregister_family+0x8b0/0x8b0 [ 34.703252] ? lock_downgrade+0x8f0/0x8f0 [ 34.707392] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 34.712444] ? kasan_check_read+0x11/0x20 [ 34.716581] ? lock_acquire+0x1e4/0x540 [ 34.720596] ? genl_rcv+0x19/0x40 [ 34.724048] ? radix_tree_lookup+0x21/0x30 [ 34.728272] genl_rcv_msg+0xc6/0x168 [ 34.731972] netlink_rcv_skb+0x172/0x440 [ 34.736021] ? genl_family_rcv_msg+0x1140/0x1140 [ 34.740841] ? netlink_ack+0xbe0/0xbe0 [ 34.744736] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 34.749151] genl_rcv+0x28/0x40 [ 34.752414] netlink_unicast+0x5a0/0x760 [ 34.756516] ? netlink_attachskb+0x9a0/0x9a0 [ 34.760957] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 34.766485] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 34.771584] netlink_sendmsg+0xa18/0xfc0 [ 34.775629] ? netlink_unicast+0x760/0x760 [ 34.779973] ? move_addr_to_kernel.part.18+0x100/0x100 [ 34.785235] ? security_socket_sendmsg+0x94/0xc0 [ 34.789973] ? netlink_unicast+0x760/0x760 [ 34.794191] sock_sendmsg+0xd5/0x120 [ 34.797891] ___sys_sendmsg+0x7fd/0x930 [ 34.801855] ? copy_msghdr_from_user+0x580/0x580 [ 34.806595] ? graph_lock+0x170/0x170 [ 34.810381] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 34.815906] ? __fget_light+0x2f7/0x440 [ 34.819865] ? fget_raw+0x20/0x20 [ 34.823306] ? lock_downgrade+0x8f0/0x8f0 [ 34.827436] ? handle_mm_fault+0x8c4/0xc80 [ 34.831652] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 34.837171] ? sockfd_lookup_light+0xc5/0x160 [ 34.841650] __sys_sendmsg+0x11d/0x290 [ 34.845521] ? __ia32_sys_shutdown+0x80/0x80 [ 34.849917] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 34.855508] ? __do_page_fault+0x449/0xe50 [ 34.859757] __x64_sys_sendmsg+0x78/0xb0 [ 34.863816] do_syscall_64+0x1b9/0x820 [ 34.867691] ? syscall_return_slowpath+0x5e0/0x5e0 [ 34.872606] ? syscall_return_slowpath+0x31d/0x5e0 [ 34.877521] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 34.883048] ? retint_user+0x18/0x18 [ 34.886747] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 34.891572] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.896742] RIP: 0033:0x440169 [ 34.899907] 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 [ 34.919037] RSP: 002b:00007ffd678b1a68 EFLAGS: 00000213 ORIG_RAX: 000000000000002e [ 34.