[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 24.048061] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 26.467618] random: sshd: uninitialized urandom read (32 bytes read) [ 26.776836] random: sshd: uninitialized urandom read (32 bytes read) [ 27.304927] random: sshd: uninitialized urandom read (32 bytes read) [ 32.748176] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.23' (ECDSA) to the list of known hosts. [ 38.394118] random: sshd: uninitialized urandom read (32 bytes read) 2018/08/27 19:22:14 parsed 1 programs [ 39.574303] random: cc1: uninitialized urandom read (8 bytes read) 2018/08/27 19:22:16 executed programs: 0 [ 40.832757] IPVS: ftp: loaded support on port[0] = 21 [ 41.044882] bridge0: port 1(bridge_slave_0) entered blocking state [ 41.051481] bridge0: port 1(bridge_slave_0) entered disabled state [ 41.058944] device bridge_slave_0 entered promiscuous mode [ 41.075624] bridge0: port 2(bridge_slave_1) entered blocking state [ 41.082089] bridge0: port 2(bridge_slave_1) entered disabled state [ 41.089063] device bridge_slave_1 entered promiscuous mode [ 41.105250] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 41.121246] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready [ 41.164925] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 41.183517] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 41.252439] IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready [ 41.259795] team0: Port device team_slave_0 added [ 41.275110] IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready [ 41.282280] team0: Port device team_slave_1 added [ 41.297804] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 41.314754] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 41.333080] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 41.350492] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready [ 41.474182] bridge0: port 2(bridge_slave_1) entered blocking state [ 41.480819] bridge0: port 2(bridge_slave_1) entered forwarding state [ 41.487729] bridge0: port 1(bridge_slave_0) entered blocking state [ 41.494098] bridge0: port 1(bridge_slave_0) entered forwarding state [ 41.936438] IPv6: ADDRCONF(NETDEV_UP): bond0: link is not ready [ 41.942560] 8021q: adding VLAN 0 to HW filter on device bond0 [ 41.986787] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 41.998122] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 42.038146] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 42.044319] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 42.052293] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 42.091904] 8021q: adding VLAN 0 to HW filter on device team0 2018/08/27 19:22:21 executed programs: 191 [ 46.816400] [ 46.818057] ===================================== [ 46.822876] WARNING: bad unlock balance detected! [ 46.827697] 4.19.0-rc1+ #211 Not tainted [ 46.831731] ------------------------------------- [ 46.836956] syz-executor0/6666 is trying to release lock (&file->mut) at: [ 46.843880] [] ucma_destroy_id+0x2cb/0x550 [ 46.849654] but there are no more locks to release! [ 46.854648] [ 46.854648] other info that might help us debug this: [ 46.861293] 1 lock held by syz-executor0/6666: [ 46.865852] #0: 00000000faad4ebe (&file->mut){+.+.}, at: ucma_destroy_id+0x26b/0x550 [ 46.873838] [ 46.873838] stack backtrace: [ 46.878364] CPU: 0 PID: 6666 Comm: syz-executor0 Not tainted 4.19.0-rc1+ #211 [ 46.885622] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.894973] Call Trace: [ 46.897551] dump_stack+0x1c9/0x2b4 [ 46.901178] ? dump_stack_print_info.cold.2+0x52/0x52 [ 46.906380] ? vprintk_func+0x81/0x117 [ 46.910253] ? ucma_destroy_id+0x2cb/0x550 [ 46.914473] print_unlock_imbalance_bug.cold.49+0xcc/0xd8 [ 46.919999] lock_release+0x76e/0x9f0 [ 46.923781] ? ucma_destroy_id+0x2cb/0x550 [ 46.928000] ? lock_downgrade+0x8f0/0x8f0 [ 46.932131] ? radix_tree_descend+0x2e0/0x2e0 [ 46.936613] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 46.942248] ? node_tag_set+0xc4/0x160 [ 46.946126] __mutex_unlock_slowpath+0x102/0x8c0 [ 46.950863] ? wait_for_completion+0x8d0/0x8d0 [ 46.955428] ? radix_tree_delete_item+0x188/0x350 [ 46.960275] ? radix_tree_lookup+0x30/0x30 [ 46.964498] mutex_unlock+0xd/0x10 [ 46.968023] ucma_destroy_id+0x2cb/0x550 [ 46.972075] ? ucma_close+0x300/0x300 [ 46.975865] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 46.981401] ? _copy_from_user+0xdf/0x150 [ 46.985540] ? ucma_close+0x300/0x300 [ 46.989334] ucma_write+0x336/0x420 [ 46.992965] ? ucma_close_id+0x60/0x60 [ 46.996857] ? kasan_check_read+0x11/0x20 [ 47.000994] ? do_raw_spin_unlock+0xa7/0x2f0 [ 47.005394] __vfs_write+0x117/0x9d0 [ 47.009099] ? __fget_light+0x2f7/0x440 [ 47.013059] ? ucma_close_id+0x60/0x60 [ 47.016935] ? kernel_read+0x120/0x120 [ 47.020813] ? trace_hardirqs_on+0x2c0/0x2c0 [ 47.025234] ? kasan_check_read+0x11/0x20 [ 47.029382] ? schedule+0xfb/0x450 [ 47.032912] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 47.038435] ? security_file_permission+0x1c2/0x230 [ 47.043447] ? rw_verify_area+0x118/0x360 [ 47.047581] vfs_write+0x1fc/0x560 [ 47.051129] ksys_write+0x101/0x260 [ 47.054739] ? __ia32_sys_read+0xb0/0xb0 [ 47.058782] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 47.063868] __x64_sys_write+0x73/0xb0 [ 47.067745] do_syscall_64+0x1b9/0x820 [ 47.071634] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 47.076989] ? syscall_return_slowpath+0x5e0/0x5e0 [ 47.081904] ? trace_hardirqs_on_caller+0x2b0/0x2b0 [ 47.086907] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 47.091922] ? recalc_sigpending_tsk+0x180/0x180 [ 47.096670] ? kasan_check_write+0x14/0x20 [ 47.100891] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 47.105722] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.110894] RIP: 0033:0x457089 [ 47.114068] Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 47.132962] RSP: 002b:00007f3d32b48c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 47.140666] RAX: ffffffffffffffda RBX: 00007f3d32b496d4 RCX: 0000000000457089 [ 47.147924] RDX: 0000000000000018 RSI: 0000000020000480 RDI: 0000000000000005 [ 47.155189] RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000 [ 47.162445] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff [ 47.169701] R13: 00000000004d7470 R14: 00000000004c17a8 R15: 0000000000000001