[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 14.338649] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 20.293835] random: sshd: uninitialized urandom read (32 bytes read) [ 20.781336] random: sshd: uninitialized urandom read (32 bytes read) [ 21.636049] random: sshd: uninitialized urandom read (32 bytes read) [ 21.780198] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.57' (ECDSA) to the list of known hosts. [ 27.272754] 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 [ 27.359833] 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 [ 27.446953] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 27.458648] 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 [ 27.502985] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready [ 27.514352] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready [ 27.557409] IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready [ 27.569329] IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready [ 27.581349] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready RTNETLINK answers: Operation not supported [ 27.602941] 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" [ 28.095273] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 28.121198] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 28.127368] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 28.134153] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready Cannot find device "team0" [ 28.287899] [ 28.289546] ====================================================== [ 28.295841] [ INFO: possible circular locking dependency detected ] [ 28.302216] 4.9.110-g00a0bcb #4 Not tainted [ 28.306534] ------------------------------------------------------- [ 28.312908] syz-executor048/3803 is trying to acquire lock: [ 28.318588] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 28.326399] but task is already holding lock: [ 28.331073] (sk_lock-AF_INET){+.+.+.}, at: [] do_ip_setsockopt.isra.13+0x269/0x2b10 [ 28.340867] which lock already depends on the new lock. [ 28.340867] [ 28.347850] [ 28.347850] the existing dependency chain (in reverse order) is: [ 28.355448] -> #1 (sk_lock-AF_INET){+.+.+.}: [ 28.360508] lock_acquire+0x130/0x3e0 [ 28.364800] lock_sock_nested+0xc6/0x120 [ 28.369356] ip_mc_config+0x147/0x1f0 [ 28.373648] inet_rtm_newaddr+0xb1b/0xef0 [ 28.378288] rtnetlink_rcv_msg+0x49c/0x650 [ 28.383023] netlink_rcv_skb+0x145/0x370 [ 28.387595] rtnetlink_rcv+0x2a/0x40 [ 28.391801] netlink_unicast+0x4d8/0x6f0 [ 28.396355] netlink_sendmsg+0x795/0xc30 [ 28.400909] sock_sendmsg+0xcc/0x110 [ 28.405114] ___sys_sendmsg+0x6fc/0x840 [ 28.409582] __sys_sendmsg+0xd9/0x190 [ 28.413884] SyS_sendmsg+0x2d/0x50 [ 28.417923] do_syscall_64+0x1a6/0x490 [ 28.422308] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 28.427900] -> #0 (rtnl_mutex){+.+.+.}: [ 28.432504] __lock_acquire+0x3019/0x4070 [ 28.437144] lock_acquire+0x130/0x3e0 [ 28.441445] mutex_lock_nested+0xc0/0x870 [ 28.446087] rtnl_lock+0x17/0x20 [ 28.449947] mrtsock_destruct+0x3b/0x1e0 [ 28.454507] ip_ra_control+0x2c2/0x420 [ 28.458893] do_ip_setsockopt.isra.13+0x15ff/0x2b10 [ 28.464404] ip_setsockopt+0x3a/0xb0 [ 28.468617] raw_setsockopt+0xb7/0xd0 [ 28.472919] sock_common_setsockopt+0x9a/0xe0 [ 28.477917] SyS_setsockopt+0x166/0x260 [ 28.482393] do_syscall_64+0x1a6/0x490 [ 28.486780] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 28.492372] [ 28.492372] other info that might help us debug this: [ 28.492372] [ 28.500489] Possible unsafe locking scenario: [ 28.500489] [ 28.506521] CPU0 CPU1 [ 28.511162] ---- ---- [ 28.515799] lock(sk_lock-AF_INET); [ 28.519734] lock(rtnl_mutex); [ 28.525748] lock(sk_lock-AF_INET); [ 28.532197] lock(rtnl_mutex); [ 28.535697] [ 28.535697] *** DEADLOCK *** [ 28.535697] [ 28.541728] 1 lock held by syz-executor048/3803: [ 28.546453] #0: (sk_lock-AF_INET){+.+.+.}, at: [] do_ip_setsockopt.isra.13+0x269/0x2b10 [ 28.556799] [ 28.556799] stack backtrace: [ 28.561269] CPU: 1 PID: 3803 Comm: syz-executor048 Not tainted 4.9.110-g00a0bcb #4 [ 28.568947] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.578288] ffff8801d9aff5f8 ffffffff81eb2329 ffffffff8559d0a0 ffffffff855e7b60 [ 28.586289] ffffffff8559d0a0 ffff8801b873e8e8 ffff8801b873e000 ffff8801d9aff640 [ 28.594279] ffffffff814262d4 0000000000000001 00000000b873e000 0000000000000001 [ 28.602281] Call Trace: [ 28.604846] [] dump_stack+0xc1/0x128 [ 28.610188] [] print_circular_bug.cold.51+0x1bd/0x27d [ 28.617005] [] __lock_acquire+0x3019/0x4070 [ 28.622951] [] ? debug_check_no_locks_freed+0x210/0x210 [ 28.629936] [] ? add_lock_to_list.isra.27.constprop.41+0x140/0x1c0 [ 28.637878] [] ? __lock_is_held+0xa2/0xf0 [ 28.643648] [] lock_acquire+0x130/0x3e0 [ 28.649247] [] ? rtnl_lock+0x17/0x20 [ 28.654580] [] ? rtnl_lock+0x17/0x20 [ 28.659921] [] mutex_lock_nested+0xc0/0x870 [ 28.665867] [] ? rtnl_lock+0x17/0x20 [ 28.671219] [] ? mutex_trylock+0x3e0/0x3e0 [ 28.677081] [] ? mark_held_locks+0xc7/0x130 [ 28.683035] [] ? __local_bh_enable_ip+0x6a/0xd0 [ 28.689340] [] rtnl_lock+0x17/0x20 [ 28.694508] [] mrtsock_destruct+0x3b/0x1e0 [ 28.700365] [] ? mroute_clean_tables+0x500/0x500 [ 28.706742] [] ip_ra_control+0x2c2/0x420 [ 28.712427] [] do_ip_setsockopt.isra.13+0x15ff/0x2b10 [ 28.719247] [] ? ip_ra_control+0x420/0x420 [ 28.725114] [] ? get_empty_filp+0x8f/0x380 [ 28.730985] [] ? alloc_file+0x20/0x350 [ 28.736515] [] ? sock_alloc_file+0x151/0x330 [ 28.742550] [] ? sock_map_fd+0x34/0x70 [ 28.748070] [] ? SyS_socket+0x10f/0x1b0 [ 28.753689] [] ? do_syscall_64+0x1a6/0x490 [ 28.759567] [] ? entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 28.766662] [] ? debug_check_no_locks_freed+0x210/0x210 [ 28.773656] [] ? debug_check_no_locks_freed+0x210/0x210 [ 28.780651] [] ? check_preemption_disabled+0x3b/0x170 [ 28.787465] [] ? sock_has_perm+0x1c2/0x3e0 [ 28.793322] [] ? sock_has_perm+0x292/0x3e0 [ 28.799177] [] ? sock_has_perm+0x9f/0x3e0 [ 28.804948] [] ? selinux_file_send_sigiotask+0x310/0x310 [ 28.812030] [] ? selinux_netlbl_socket_setsockopt+0x8c/0x340 [ 28.819447] [] ? selinux_netlbl_sock_rcv_skb+0x480/0x480 [ 28.826523] [] ip_setsockopt+0x3a/0xb0 [ 28.832035] [] raw_setsockopt+0xb7/0xd0 executing program [ 28.837634] [] sock_common_setsockopt+0x9a/0xe0 [ 28.843924] [] SyS_setsockopt+0x166/0x260 [ 28.849693] [] ? SyS_recv+0x40/0x40 [ 28.854942] [] ? move_addr_to_kernel+0x50/0x50 [ 28.861151] [] ? do_syscall_64+0x48/0x490 [ 28.866927] [] ? SyS_recv+0x40/0x40 [ 28.872181] [] do_syscall_64+0x1a6/0x490 [ 28.877870] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb