[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 33.513262] random: sshd: uninitialized urandom read (32 bytes read) Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 33.964383] kauditd_printk_skb: 11 callbacks suppressed [ 33.964391] audit: type=1400 audit(1578278566.888:35): avc: denied { map } for pid=7134 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 [ 34.019280] random: sshd: uninitialized urandom read (32 bytes read) [ 34.637076] random: sshd: uninitialized urandom read (32 bytes read) [ 34.824359] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.79' (ECDSA) to the list of known hosts. [ 40.384887] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 40.501676] audit: type=1400 audit(1578278573.428:36): avc: denied { map } for pid=7147 comm="syz-executor373" path="/root/syz-executor373827157" dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 40.505099] netlink: 20 bytes leftover after parsing attributes in process `syz-executor373'. [ 40.546439] netlink: 20 bytes leftover after parsing attributes in process `syz-executor373'. [ 40.610897] [ 40.612583] ============================================ [ 40.618174] WARNING: possible recursive locking detected [ 40.623648] 4.14.162-syzkaller #0 Not tainted [ 40.628229] -------------------------------------------- [ 40.633711] syz-executor373/7147 is trying to acquire lock: [ 40.639535] (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x17/0x20 [ 40.646870] [ 40.646870] but task is already holding lock: [ 40.652841] (rtnl_mutex){+.+.}, at: [] rtnetlink_rcv_msg+0x339/0xb70 [ 40.660998] [ 40.660998] other info that might help us debug this: [ 40.667662] Possible unsafe locking scenario: [ 40.667662] [ 40.673876] CPU0 [ 40.676457] ---- [ 40.679067] lock(rtnl_mutex); [ 40.682358] lock(rtnl_mutex); [ 40.685816] [ 40.685816] *** DEADLOCK *** [ 40.685816] [ 40.692049] May be due to missing lock nesting notation [ 40.692049] [ 40.698976] 1 lock held by syz-executor373/7147: [ 40.703736] #0: (rtnl_mutex){+.+.}, at: [] rtnetlink_rcv_msg+0x339/0xb70 [ 40.712330] [ 40.712330] stack backtrace: [ 40.716917] CPU: 1 PID: 7147 Comm: syz-executor373 Not tainted 4.14.162-syzkaller #0 [ 40.724797] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.734208] Call Trace: [ 40.736818] dump_stack+0x142/0x197 [ 40.740610] __lock_acquire.cold+0x2bf/0x8dc [ 40.745033] ? save_trace+0x290/0x290 [ 40.748840] ? trace_hardirqs_on_caller+0x400/0x590 [ 40.753913] ? trace_hardirqs_on+0x10/0x10 [ 40.758154] ? put_dec+0xc0/0xc0 [ 40.761527] ? format_decode+0x1d8/0x930 [ 40.765692] ? save_trace+0x290/0x290 [ 40.769503] ? set_precision+0x150/0x150 [ 40.773579] ? __lock_is_held+0xb6/0x140 [ 40.777648] lock_acquire+0x16f/0x430 [ 40.781463] ? rtnl_lock+0x17/0x20 [ 40.785185] ? rtnl_lock+0x17/0x20 [ 40.788728] __mutex_lock+0xe8/0x1470 [ 40.792554] ? rtnl_lock+0x17/0x20 [ 40.796098] ? vsprintf+0x40/0x40 [ 40.799574] ? rtnl_lock+0x17/0x20 [ 40.803115] ? mutex_trylock+0x1c0/0x1c0 [ 40.807174] ? __dev_alloc_name+0x251/0x2c0 [ 40.811497] ? __lock_is_held+0xb6/0x140 [ 40.815560] ? __dev_get_by_name+0x140/0x140 [ 40.819970] ? memcpy+0x46/0x50 [ 40.823251] ? hsr_dev_close+0x10/0x10 [ 40.827142] mutex_lock_nested+0x16/0x20 [ 40.831202] ? mutex_lock_nested+0x16/0x20 [ 40.835445] rtnl_lock+0x17/0x20 [ 40.838836] hsr_dev_destroy+0x1f/0xc0 [ 40.842730] ? hsr_dev_close+0x10/0x10 [ 40.846643] register_netdevice+0x7da/0xca0 [ 40.851080] ? netdev_change_features+0x80/0x80 [ 40.855750] ? hsr_add_port+0x42a/0x610 [ 40.859727] hsr_dev_finalize+0x582/0x80a [ 40.863877] hsr_newlink+0x250/0x340 [ 40.867590] ? send_hsr_supervision_frame.cold+0x26/0x26 [ 40.874310] ? rtnl_create_link+0x12c/0x850 [ 40.878635] rtnl_newlink+0xecb/0x1700 [ 40.882543] ? send_hsr_supervision_frame.cold+0x26/0x26 [ 40.887995] ? rtnl_link_unregister+0x200/0x200 [ 40.892699] ? avc_has_perm_noaudit+0x2b2/0x420 [ 40.897380] ? lock_acquire+0x16f/0x430 [ 40.901363] ? rtnetlink_rcv_msg+0x339/0xb70 [ 40.905978] ? rtnl_link_unregister+0x200/0x200 [ 40.910659] rtnetlink_rcv_msg+0x3da/0xb70 [ 40.915023] ? rtnl_bridge_getlink+0x7a0/0x7a0 [ 40.919905] ? netlink_deliver_tap+0x93/0x8f0 [ 40.924534] netlink_rcv_skb+0x14f/0x3c0 [ 40.928584] ? rtnl_bridge_getlink+0x7a0/0x7a0 [ 40.933160] ? lock_downgrade+0x740/0x740 [ 40.937358] ? netlink_ack+0x9a0/0x9a0 [ 40.941344] ? netlink_deliver_tap+0xba/0x8f0 [ 40.945889] rtnetlink_rcv+0x1d/0x30 [ 40.949860] netlink_unicast+0x44d/0x650 [ 40.954229] ? netlink_attachskb+0x6a0/0x6a0 [ 40.958639] ? security_netlink_send+0x81/0xb0 [ 40.963598] netlink_sendmsg+0x7c4/0xc60 [ 40.967788] ? netlink_unicast+0x650/0x650 [ 40.972215] ? security_socket_sendmsg+0x89/0xb0 [ 40.977097] ? netlink_unicast+0x650/0x650 [ 40.981335] sock_sendmsg+0xce/0x110 [ 40.985052] ___sys_sendmsg+0x70a/0x840 [ 40.989022] ? copy_msghdr_from_user+0x3f0/0x3f0 [ 40.993768] ? __might_fault+0x110/0x1d0 [ 40.997855] ? find_held_lock+0x35/0x130 [ 41.001906] ? __might_fault+0x110/0x1d0 [ 41.005963] ? lock_downgrade+0x740/0x740 [ 41.010106] ? kasan_check_read+0x11/0x20 [ 41.014533] ? _copy_to_user+0x87/0xd0 [ 41.018501] ? move_addr_to_user+0x94/0x1a0 [ 41.022819] ? __fget_light+0x172/0x1f0 [ 41.026793] ? __fdget+0x1b/0x20 [ 41.030153] ? sockfd_lookup_light+0xb4/0x160 [ 41.036138] __sys_sendmsg+0xb9/0x140 [ 41.039930] ? SyS_shutdown+0x170/0x170 [ 41.043899] ? fd_install+0x4d/0x60 [ 41.047553] SyS_sendmsg+0x2d/0x50 [ 41.051084] ? __sys_sendmsg+0x140/0x140 [ 41.055174] do_syscall_64+0x1e8/0x640 [ 41.059046] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 41.063896] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 41.069317] RIP: 0033:0x4408e9 [ 41.072674] RSP: 002b:00007fff7fd6a9a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 41.080554] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004408e9 [ 41.087943] RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000003 [ 41.095353] RBP: 00000000006cb018 R08: 0000000000000002 R09: 00000000004002c8 [ 41.102852] R10: 0000000000000014 R11: 0000000000000246 R12: 0000000000402170 [ 41.111042] R13: 0000000000402200 R14: 0000000000000000 R15: 0000000000000000