[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 13.663731] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 16.125023] random: sshd: uninitialized urandom read (32 bytes read) [ 16.497597] random: sshd: uninitialized urandom read (32 bytes read) [ 17.287353] random: sshd: uninitialized urandom read (32 bytes read) [ 17.427654] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.48' (ECDSA) to the list of known hosts. [ 22.935098] random: sshd: uninitialized urandom read (32 bytes read) RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported [ 23.014538] IPVS: Creating netns size=2536 id=1 RTNETLINK answers: Operation not supported Error: argument "bridge0" is wrong: Device does not exist Error: argument "bridge0" is wrong: Device does not exist Error: argument "bond0" is wrong: Device does not exist Error: argument "bond0" is wrong: Device does not exist [ 23.097471] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 23.109046] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready Error: argument "team0" is wrong: Device does not exist Error: argument "team0" is wrong: Device does not exist [ 23.152731] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready [ 23.164325] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready [ 23.206640] IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready [ 23.217907] IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready [ 23.229585] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 23.250690] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready RTNETLINK answers: Operation not supported Cannot find device "bridge0" Cannot find device "bridge0" Cannot find device "bridge0" Cannot find device "bridge0" [ 23.277953] ip (3873) used greatest stack depth: 24056 bytes left Cannot find device "vcan0" Cannot find device "vcan0" Cannot find device "vcan0" Cannot find device "vcan0" RTNETLINK answers: Operation not supported Cannot find device "gre0" Cannot find device "gre0" Cannot find device "gre0" Cannot find device "gre0" Cannot find device "gretap0" Cannot find device "gretap0" Cannot find device "gretap0" Cannot find device "gretap0" Cannot find device "ip_vti0" Cannot find device "ip_vti0" Cannot find device "ip_vti0" Cannot find device "ip_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6tnl0" Cannot find device "ip6tnl0" Cannot find device "ip6tnl0" Cannot find device "ip6tnl0" Cannot find device "ip6gre0" Cannot find device "ip6gre0" Cannot find device "ip6gre0" Cannot find device "ip6gre0" Cannot find device "ip6gretap0" Cannot find device "ip6gretap0" Cannot find device "ip6gretap0" Cannot find device "ip6gretap0" Cannot find device "erspan0" Cannot find device "erspan0" Cannot find device "erspan0" Cannot find device "erspan0" Cannot find device "bond0" Cannot find device "bond0" Cannot find device "bond0" Cannot find device "bond0" Cannot find device "team0" Cannot find device "team0" Cannot find device "team0" Cannot find device "team0" [ 23.731803] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 23.756382] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 23.762620] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 23.769332] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready executing program [ 23.944336] [ 23.945990] ====================================================== [ 23.950954] IPVS: sync thread started: state = BACKUP, mcast_ifn = veth1_to_bond, syncid = 0, id = 0 [ 23.961514] [ INFO: possible circular locking dependency detected ] [ 23.967891] 4.9.109-ga4230be #48 Not tainted [ 23.972277] ------------------------------------------------------- [ 23.978652] syz-executor546/3792 is trying to acquire lock: [ 23.984332] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 23.992136] but task is already holding lock: [ 23.996783] (sk_lock-AF_INET){+.+.+.}, at: [] do_ip_setsockopt.isra.13+0x269/0x2b10 [ 24.006567] which lock already depends on the new lock. [ 24.006567] [ 24.013557] [ 24.013557] the existing dependency chain (in reverse order) is: [ 24.021147] -> #1 (sk_lock-AF_INET){+.+.+.}: [ 24.026200] lock_acquire+0x130/0x3e0 [ 24.030495] lock_sock_nested+0xc6/0x120 [ 24.035057] inet_bind+0x2a6/0x8b0 [ 24.039090] start_sync_thread+0x1356/0x1e80 [ 24.043993] do_ip_vs_set_ctl+0x90f/0xbb0 [ 24.048642] nf_setsockopt+0x6d/0xc0 [ 24.052850] ip_setsockopt+0x9a/0xb0 [ 24.057058] udp_setsockopt+0x4a/0x90 [ 24.061354] ipv6_setsockopt+0x10a/0x130 [ 24.065908] tcp_setsockopt+0x88/0xe0 [ 24.070202] sock_common_setsockopt+0x9a/0xe0 [ 24.075222] SyS_setsockopt+0x166/0x260 [ 24.079691] do_syscall_64+0x1a6/0x490 [ 24.084072] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 24.089665] -> #0 (rtnl_mutex){+.+.+.}: [ 24.094273] __lock_acquire+0x3019/0x4070 [ 24.098912] lock_acquire+0x130/0x3e0 [ 24.103206] mutex_lock_nested+0xc0/0x870 [ 24.107847] rtnl_lock+0x17/0x20 [ 24.111708] mrtsock_destruct+0x3b/0x1e0 [ 24.116260] ip_ra_control+0x2c2/0x420 [ 24.120639] do_ip_setsockopt.isra.13+0x15ff/0x2b10 [ 24.126159] ip_setsockopt+0x3a/0xb0 [ 24.130366] raw_setsockopt+0xb7/0xd0 [ 24.134659] sock_common_setsockopt+0x9a/0xe0 [ 24.139649] SyS_setsockopt+0x166/0x260 [ 24.144116] do_syscall_64+0x1a6/0x490 [ 24.148505] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 24.154099] [ 24.154099] other info that might help us debug this: [ 24.154099] [ 24.162212] Possible unsafe locking scenario: [ 24.162212] [ 24.168248] CPU0 CPU1 [ 24.172884] ---- ---- [ 24.177523] lock(sk_lock-AF_INET); [ 24.181451] lock(rtnl_mutex); [ 24.187465] lock(sk_lock-AF_INET); [ 24.193940] lock(rtnl_mutex); [ 24.197430] [ 24.197430] *** DEADLOCK *** [ 24.197430] [ 24.203472] 1 lock held by syz-executor546/3792: [ 24.208197] #0: (sk_lock-AF_INET){+.+.+.}, at: [] do_ip_setsockopt.isra.13+0x269/0x2b10 [ 24.218527] [ 24.218527] stack backtrace: [ 24.222998] CPU: 0 PID: 3792 Comm: syz-executor546 Not tainted 4.9.109-ga4230be #48 [ 24.230762] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 24.240092] ffff8801b6ec75f8 ffffffff81eb3e29 ffffffff8559cef0 ffffffff855e79b0 [ 24.248094] ffffffff8559cef0 ffff8801b89568e8 ffff8801b8956000 ffff8801b6ec7640 [ 24.256094] ffffffff814262d4 0000000000000001 00000000b8956000 0000000000000001 [ 24.264074] Call Trace: [ 24.266636] [] dump_stack+0xc1/0x128 [ 24.271976] [] print_circular_bug.cold.51+0x1bd/0x27d [ 24.278797] [] __lock_acquire+0x3019/0x4070 [ 24.284749] [] ? debug_check_no_locks_freed+0x210/0x210 [ 24.291736] [] ? add_lock_to_list.isra.27.constprop.41+0x140/0x1c0 [ 24.299677] [] ? __lock_is_held+0xa2/0xf0 [ 24.305448] [] lock_acquire+0x130/0x3e0 [ 24.311047] [] ? rtnl_lock+0x17/0x20 [ 24.316381] [] ? rtnl_lock+0x17/0x20 [ 24.321736] [] mutex_lock_nested+0xc0/0x870 [ 24.327679] [] ? rtnl_lock+0x17/0x20 [ 24.333019] [] ? mutex_trylock+0x3e0/0x3e0 [ 24.338887] [] ? mark_held_locks+0xc7/0x130 [ 24.344840] [] ? __local_bh_enable_ip+0x6a/0xd0 [ 24.351141] [] rtnl_lock+0x17/0x20 [ 24.356304] [] mrtsock_destruct+0x3b/0x1e0 [ 24.362167] [] ? mroute_clean_tables+0x500/0x500 [ 24.368544] [] ip_ra_control+0x2c2/0x420 [ 24.374226] [] do_ip_setsockopt.isra.13+0x15ff/0x2b10 [ 24.381047] [] ? ip_ra_control+0x420/0x420 [ 24.386905] [] ? get_empty_filp+0x8f/0x380 [ 24.392762] [] ? alloc_file+0x20/0x350 [ 24.398280] [] ? sock_alloc_file+0x151/0x330 [ 24.404319] [] ? sock_map_fd+0x34/0x70 [ 24.409838] [] ? SyS_socket+0x10f/0x1b0 [ 24.415445] [] ? do_syscall_64+0x1a6/0x490 [ 24.421303] [] ? entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 24.428377] [] ? debug_check_no_locks_freed+0x210/0x210 [ 24.435450] [] ? debug_check_no_locks_freed+0x210/0x210 [ 24.442437] [] ? check_preemption_disabled+0x3b/0x170 [ 24.449250] [] ? sock_has_perm+0x1c2/0x3e0 [ 24.455115] [] ? sock_has_perm+0x292/0x3e0 [ 24.460972] [] ? sock_has_perm+0x9f/0x3e0 [ 24.466746] [] ? selinux_file_send_sigiotask+0x310/0x310 [ 24.473819] [] ? selinux_netlbl_socket_setsockopt+0x8c/0x340 [ 24.481243] [] ? selinux_netlbl_sock_rcv_skb+0x480/0x480 [ 24.488319] [] ip_setsockopt+0x3a/0xb0 [ 24.493836] [] raw_setsockopt+0xb7/0xd0 [ 24.499432] [] sock_common_setsockopt+0x9a/0xe0 [ 24.505727] [] SyS_setsockopt+0x166/0x260 [ 24.511498] [] ? SyS_recv+0x40/0x40 [ 24.516752] [] ? __do_page_fault+0x183/0xd50 [ 24.522783] [] ? move_addr_to_kernel+0x50/0x50 [ 24.528989] [] ? do_syscall_64+0x48/0x490 [ 24.534762] [] ? SyS_recv+0x40/0x40 [ 24.540013] [] do_syscall_64+0x1a6/0x490 [ 24.545713] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb