[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 39.832415] audit: type=1800 audit(1550506189.847:25): pid=7821 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 39.865191] audit: type=1800 audit(1550506189.847:26): pid=7821 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 39.895415] audit: type=1800 audit(1550506189.857:27): pid=7821 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.10.32' (ECDSA) to the list of known hosts. 2019/02/18 16:09:59 parsed 1 programs 2019/02/18 16:10:01 executed programs: 0 syzkaller login: [ 51.568123] IPVS: ftp: loaded support on port[0] = 21 [ 51.640087] chnl_net:caif_netlink_parms(): no params data found [ 51.674162] bridge0: port 1(bridge_slave_0) entered blocking state [ 51.681008] bridge0: port 1(bridge_slave_0) entered disabled state [ 51.688133] device bridge_slave_0 entered promiscuous mode [ 51.695257] bridge0: port 2(bridge_slave_1) entered blocking state [ 51.701748] bridge0: port 2(bridge_slave_1) entered disabled state [ 51.708728] device bridge_slave_1 entered promiscuous mode [ 51.725106] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 51.734611] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 51.752241] team0: Port device team_slave_0 added [ 51.758483] team0: Port device team_slave_1 added [ 51.839131] device hsr_slave_0 entered promiscuous mode [ 51.917444] device hsr_slave_1 entered promiscuous mode [ 51.994772] bridge0: port 2(bridge_slave_1) entered blocking state [ 52.001243] bridge0: port 2(bridge_slave_1) entered forwarding state [ 52.008302] bridge0: port 1(bridge_slave_0) entered blocking state [ 52.014648] bridge0: port 1(bridge_slave_0) entered forwarding state [ 52.043364] 8021q: adding VLAN 0 to HW filter on device bond0 [ 52.054979] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 52.073966] bridge0: port 1(bridge_slave_0) entered disabled state [ 52.081806] bridge0: port 2(bridge_slave_1) entered disabled state [ 52.090040] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 52.100230] 8021q: adding VLAN 0 to HW filter on device team0 [ 52.109560] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready [ 52.117267] bridge0: port 1(bridge_slave_0) entered blocking state [ 52.123630] bridge0: port 1(bridge_slave_0) entered forwarding state [ 52.132951] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready [ 52.141760] bridge0: port 2(bridge_slave_1) entered blocking state [ 52.148152] bridge0: port 2(bridge_slave_1) entered forwarding state [ 52.170438] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 52.178419] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 52.186004] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready [ 52.194104] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready [ 52.201716] IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready [ 52.210679] IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready [ 52.228757] 8021q: adding VLAN 0 to HW filter on device batadv0 [ 54.022509] [ 54.024182] ===================================== [ 54.029002] WARNING: bad unlock balance detected! [ 54.033820] 5.0.0-rc6+ #76 Not tainted [ 54.037699] ------------------------------------- [ 54.042520] syz-executor.0/8448 is trying to release lock (&file->mut) at: [ 54.049524] [] ucma_destroy_id+0x24c/0x4a0 [ 54.055297] but there are no more locks to release! [ 54.060288] [ 54.060288] other info that might help us debug this: [ 54.066934] 1 lock held by syz-executor.0/8448: [ 54.071598] #0: 00000000b03a1178 (&file->mut){+.+.}, at: ucma_destroy_id+0x1e9/0x4a0 [ 54.079611] [ 54.079611] stack backtrace: [ 54.084087] CPU: 1 PID: 8448 Comm: syz-executor.0 Not tainted 5.0.0-rc6+ #76 [ 54.091250] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 54.100596] Call Trace: [ 54.103182] dump_stack+0x172/0x1f0 [ 54.106792] ? ucma_destroy_id+0x24c/0x4a0 [ 54.111029] print_unlock_imbalance_bug.cold+0x114/0x123 [ 54.116475] ? ucma_destroy_id+0x24c/0x4a0 [ 54.120690] lock_release+0x67e/0xa00 [ 54.124476] ? lock_downgrade+0x810/0x810 [ 54.128618] ? mutex_trylock+0x1e0/0x1e0 [ 54.132670] __mutex_unlock_slowpath+0x8e/0x6b0 [ 54.137348] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 54.142866] ? wait_for_completion+0x440/0x440 [ 54.147442] mutex_unlock+0xd/0x10 [ 54.150985] ucma_destroy_id+0x24c/0x4a0 [ 54.155027] ? ucma_close+0x320/0x320 [ 54.158829] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 54.164347] ? _copy_from_user+0xdd/0x150 [ 54.168480] ucma_write+0x2da/0x3c0 [ 54.172085] ? ucma_close+0x320/0x320 [ 54.175866] ? ucma_open+0x290/0x290 [ 54.179558] ? __fget+0x340/0x540 [ 54.182991] __vfs_write+0x116/0x8e0 [ 54.186684] ? lock_downgrade+0x810/0x810 [ 54.190828] ? ucma_open+0x290/0x290 [ 54.194524] ? kernel_read+0x120/0x120 [ 54.198392] ? __fget+0x367/0x540 [ 54.201838] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 54.207370] ? security_file_permission+0x94/0x320 [ 54.212305] ? rw_verify_area+0x118/0x360 [ 54.216465] vfs_write+0x20c/0x580 [ 54.219992] ksys_write+0xea/0x1f0 [ 54.223551] ? __ia32_sys_read+0xb0/0xb0 [ 54.227641] ? do_syscall_64+0x26/0x610 [ 54.231603] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 54.236946] ? do_syscall_64+0x26/0x610 [ 54.240922] __x64_sys_write+0x73/0xb0 [ 54.244803] do_syscall_64+0x103/0x610 [ 54.248674] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 54.253841] RIP: 0033:0x457e29 [ 54.257010] Code: ad b8 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 54.275893] RSP: 002b:00007fb665903c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 54.283593] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e29 [ 54.290849] RDX: 0000000000000018 RSI: 0000000020000180 RDI: 0000000000000005 [ 54.298102] RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 [ 54.305355] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb6659046d4 [ 54.312610] R13: 00000000004cd790 R14: 00000000004dc9d0 R15: 00000000ffffffff