[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 12.958613] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 14.837161] random: sshd: uninitialized urandom read (32 bytes read) [ 15.033093] random: sshd: uninitialized urandom read (32 bytes read) [ 15.889887] random: sshd: uninitialized urandom read (32 bytes read) [ 19.258572] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.42' (ECDSA) to the list of known hosts. [ 24.790177] 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 RTNETLINK answers: Operation not supported [ 24.867991] IPVS: Creating netns size=2536 id=1 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 [ 24.943430] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 24.954876] 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 [ 24.995761] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready [ 25.006471] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready RTNETLINK answers: Operation not supported [ 25.045726] IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready [ 25.056535] IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready [ 25.067836] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 25.080618] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready Cannot find device "bridge0" Cannot find device "bridge0" Cannot find device "bridge0" Cannot find device "bridge0" 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" [ 25.517439] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 25.539627] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 25.545722] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 25.552514] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 25.686095] [ 25.687768] ====================================================== [ 25.694064] [ INFO: possible circular locking dependency detected ] [ 25.700438] 4.9.105-gd7e64f8 #40 Not tainted [ 25.704824] ------------------------------------------------------- [ 25.711208] syz-executor124/3795 is trying to acquire lock: [ 25.716887] (sk_lock-AF_INET){+.+.+.}, at: [] start_sync_thread+0x88b/0x1e80 [ 25.726078] but task is already holding lock: [ 25.730727] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 25.738504] which lock already depends on the new lock. [ 25.738504] [ 25.745491] [ 25.745491] the existing dependency chain (in reverse order) is: [ 25.753079] -> #1 (rtnl_mutex){+.+.+.}: [ 25.757684] lock_acquire+0x130/0x3e0 [ 25.761975] mutex_lock_nested+0xc0/0x870 [ 25.766613] rtnl_lock+0x17/0x20 [ 25.770470] mrtsock_destruct+0x3b/0x1e0 [ 25.775032] ip_ra_control+0x2c2/0x420 [ 25.779411] do_ip_setsockopt.isra.13+0x15ff/0x2b10 [ 25.784927] ip_setsockopt+0x3a/0xb0 [ 25.789133] raw_setsockopt+0xb7/0xd0 [ 25.793425] sock_common_setsockopt+0x9a/0xe0 [ 25.798421] SyS_setsockopt+0x166/0x260 [ 25.802900] do_syscall_64+0x1a6/0x490 [ 25.807280] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 25.812872] -> #0 (sk_lock-AF_INET){+.+.+.}: [ 25.817915] __lock_acquire+0x3019/0x4070 [ 25.822569] lock_acquire+0x130/0x3e0 [ 25.826864] lock_sock_nested+0xc6/0x120 [ 25.831414] start_sync_thread+0x88b/0x1e80 [ 25.836226] do_ip_vs_set_ctl+0x90f/0xbb0 [ 25.840876] nf_setsockopt+0x6d/0xc0 [ 25.845080] ip_setsockopt+0x9a/0xb0 [ 25.849286] udp_setsockopt+0x4a/0x90 [ 25.853592] ipv6_setsockopt+0x10a/0x130 [ 25.858143] tcp_setsockopt+0x88/0xe0 [ 25.862452] sock_common_setsockopt+0x9a/0xe0 [ 25.867452] SyS_setsockopt+0x166/0x260 [ 25.871918] do_syscall_64+0x1a6/0x490 [ 25.876299] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 25.881892] [ 25.881892] other info that might help us debug this: [ 25.881892] [ 25.890011] Possible unsafe locking scenario: [ 25.890011] [ 25.896037] CPU0 CPU1 [ 25.900687] ---- ---- [ 25.905336] lock(rtnl_mutex); [ 25.908821] lock(sk_lock-AF_INET); [ 25.915257] lock(rtnl_mutex); [ 25.921260] lock(sk_lock-AF_INET); [ 25.925176] [ 25.925176] *** DEADLOCK *** [ 25.925176] [ 25.931205] 2 locks held by syz-executor124/3795: [ 25.936016] #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 25.944377] #1: (ipvs->sync_mutex){+.+.+.}, at: [] start_sync_thread+0x118/0x1e80 [ 25.954178] [ 25.954178] stack backtrace: [ 25.958648] CPU: 0 PID: 3795 Comm: syz-executor124 Not tainted 4.9.105-gd7e64f8 #40 [ 25.966421] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.975757] ffff8801d9747538 ffffffff81eb41a9 ffffffff855e7690 ffffffff8559cf30 [ 25.983759] ffffffff855e7690 ffff8801b752a0e8 ffff8801b7529800 ffff8801d9747580 [ 25.991751] ffffffff8142679d 0000000000000001 00000000b7529800 0000000000000001 [ 25.999757] Call Trace: [ 26.002332] [] dump_stack+0xc1/0x128 [ 26.007671] [] print_circular_bug.cold.51+0x1bd/0x27d [ 26.014488] [] __lock_acquire+0x3019/0x4070 [ 26.020429] [] ? debug_check_no_locks_freed+0x210/0x210 [ 26.027416] [] ? netlbl_sock_setattr+0x101/0x2e0 [ 26.033800] [] ? netlbl_enabled+0x50/0x50 [ 26.039572] [] ? selinux_netlbl_socket_post_create+0xc3/0x140 [ 26.047084] [] lock_acquire+0x130/0x3e0 [ 26.052684] [] ? start_sync_thread+0x88b/0x1e80 [ 26.058975] [] lock_sock_nested+0xc6/0x120 [ 26.064829] [] ? start_sync_thread+0x88b/0x1e80 [ 26.071117] [] start_sync_thread+0x88b/0x1e80 [ 26.077243] [] ? get_curr_sync_buff.isra.1+0x141/0x141 [ 26.084139] [] ? ip_vs_sync_conn+0x2a90/0x2a90 [ 26.090341] [] ? selinux_ipv4_output+0x40/0x40 [ 26.096549] [] ? memcpy+0x45/0x50 [ 26.101629] [] do_ip_vs_set_ctl+0x90f/0xbb0 [ 26.107571] [] ? __lock_acquire+0x654/0x4070 [ 26.113604] [] ? kmem_cache_alloc+0xbe/0x290 [ 26.119634] [] ? get_empty_filp+0x8f/0x380 [ 26.125501] [] ? ip_vs_genl_set_cmd+0x9c0/0x9c0 [ 26.131792] [] ? mutex_lock_nested+0x572/0x870 [ 26.138004] [] ? __mutex_unlock_slowpath+0x221/0x3c0 [ 26.144726] [] ? __ww_mutex_lock+0x14c0/0x14c0 [ 26.151019] [] ? check_preemption_disabled+0x3b/0x170 [ 26.157840] [] ? mutex_unlock+0x9/0x10 [ 26.163348] [] ? nf_sockopt_find.constprop.0+0x1b1/0x230 [ 26.170417] [] nf_setsockopt+0x6d/0xc0 [ 26.175932] [] ip_setsockopt+0x9a/0xb0 [ 26.181443] [] udp_setsockopt+0x4a/0x90 [ 26.187040] [] ipv6_setsockopt+0x10a/0x130 [ 26.192894] [] tcp_setsockopt+0x88/0xe0 [ 26.198488] [] sock_common_setsockopt+0x9a/0xe0 [ 26.204779] [] SyS_setsockopt+0x166/0x260 [ 26.210550] [] ? SyS_recv+0x40/0x40 [ 26.215803] [] ? __do_page_fault+0x183/0xd50 [ 26.221842] [] ? move_addr_to_kernel+0x50/0x50 [ 26.228044] [] ? do_syscall_64+0x48/0x490 executing program [ 26.233811] [] ? SyS_recv+0x40/0x40 [ 26.239056] [] do_syscall_64+0x1a6/0x490 [ 26.244739] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 26.253212] IPVS: sync thread started: state = MASTER, mcast_ifn = veth0_to_bridge, syncid = 3, id = 0