[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 33.958709] kauditd_printk_skb: 8 callbacks suppressed [ 33.958718] audit: type=1800 audit(1545850844.999:29): pid=7408 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 33.990035] audit: type=1800 audit(1545850845.009:30): pid=7408 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.75' (ECDSA) to the list of known hosts. RTNETLINK answers: No buffer space available RTNETLINK answers: No buffer space available syzkaller login: [ 41.216927] IPVS: ftp: loaded support on port[0] = 21 [ 41.345590] bridge0: port 1(bridge_slave_0) entered blocking state [ 41.352449] bridge0: port 1(bridge_slave_0) entered disabled state [ 41.359288] device bridge_slave_0 entered promiscuous mode [ 41.374946] bridge0: port 2(bridge_slave_1) entered blocking state [ 41.381476] bridge0: port 2(bridge_slave_1) entered disabled state [ 41.388245] device bridge_slave_1 entered promiscuous mode [ 41.402843] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 41.418619] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready [ 41.458598] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 41.475787] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 41.535865] IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready [ 41.543016] team0: Port device team_slave_0 added [ 41.556688] IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready [ 41.564109] team0: Port device team_slave_1 added [ 41.578272] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 41.599414] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 41.616154] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 41.633318] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready RTNETLINK answers: Operation not supported RTNETLINK answers: No buffer space available RTNETLINK answers: Operation not supported [ 41.747599] bridge0: port 2(bridge_slave_1) entered blocking state [ 41.753991] bridge0: port 2(bridge_slave_1) entered forwarding state [ 41.760771] bridge0: port 1(bridge_slave_0) entered blocking state [ 41.767096] bridge0: port 1(bridge_slave_0) entered forwarding state RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Invalid argument RTNETLINK answers: Invalid argument RTNETLINK answers: Invalid argument [ 42.165282] IPv6: ADDRCONF(NETDEV_UP): bond0: link is not ready [ 42.171615] 8021q: adding VLAN 0 to HW filter on device bond0 [ 42.211913] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 42.253872] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 42.261233] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 42.298285] 8021q: adding VLAN 0 to HW filter on device team0 executing program [ 42.568486] [ 42.570139] ====================================================== [ 42.576424] WARNING: possible circular locking dependency detected [ 42.582713] 4.20.0-rc7-next-20181224 #188 Not tainted [ 42.587871] ------------------------------------------------------ [ 42.594168] syz-executor284/7816 is trying to acquire lock: [ 42.599845] 0000000061ca8a05 (&sb->s_type->i_mutex_key#12){+.+.}, at: shmem_fallocate+0x18b/0x12c0 [ 42.608922] [ 42.608922] but task is already holding lock: [ 42.614861] 000000006fa29b9a (ashmem_mutex){+.+.}, at: ashmem_shrink_scan+0xb4/0x660 [ 42.622726] [ 42.622726] which lock already depends on the new lock. [ 42.622726] [ 42.631020] [ 42.631020] the existing dependency chain (in reverse order) is: [ 42.638609] [ 42.638609] -> #2 (ashmem_mutex){+.+.}: [ 42.644038] __mutex_lock+0x166/0x1700 [ 42.648415] mutex_lock_nested+0x16/0x20 [ 42.652970] ashmem_mmap+0x55/0x520 [ 42.657088] mmap_region+0xe85/0x1cd0 [ 42.661381] do_mmap+0xa22/0x1230 [ 42.665324] vm_mmap_pgoff+0x213/0x2c0 [ 42.669704] ksys_mmap_pgoff+0x4da/0x660 [ 42.674254] __x64_sys_mmap+0xe9/0x1b0 [ 42.678635] do_syscall_64+0x1b9/0x820 [ 42.683014] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 42.688694] [ 42.688694] -> #1 (&mm->mmap_sem){++++}: [ 42.694204] down_read+0x8d/0x120 [ 42.698150] __do_page_fault+0xa0f/0xd70 [ 42.702703] do_page_fault+0xf2/0x7e0 [ 42.706996] page_fault+0x1e/0x30 [ 42.710941] iov_iter_fault_in_readable+0x1b4/0x450 [ 42.716449] generic_perform_write+0x216/0x6a0 [ 42.721525] __generic_file_write_iter+0x26e/0x630 [ 42.726948] generic_file_write_iter+0x34d/0x6b0 [ 42.732194] __vfs_write+0x72c/0xab0 [ 42.736398] vfs_write+0x1fc/0x580 [ 42.740430] ksys_write+0x101/0x260 [ 42.744549] __x64_sys_write+0x73/0xb0 [ 42.748929] do_syscall_64+0x1b9/0x820 [ 42.753307] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 42.758981] [ 42.758981] -> #0 (&sb->s_type->i_mutex_key#12){+.+.}: [ 42.765710] lock_acquire+0x1ed/0x520 [ 42.770002] down_write+0x8a/0x130 [ 42.774040] shmem_fallocate+0x18b/0x12c0 [ 42.778678] ashmem_shrink_scan+0x238/0x660 [ 42.783492] ashmem_ioctl+0x3ae/0x13a0 [ 42.787876] do_vfs_ioctl+0x1de/0x1790 [ 42.792266] ksys_ioctl+0xa9/0xd0 [ 42.796218] __x64_sys_ioctl+0x73/0xb0 [ 42.800603] do_syscall_64+0x1b9/0x820 [ 42.804984] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 42.810661] [ 42.810661] other info that might help us debug this: [ 42.810661] [ 42.818768] Chain exists of: [ 42.818768] &sb->s_type->i_mutex_key#12 --> &mm->mmap_sem --> ashmem_mutex [ 42.818768] [ 42.830267] Possible unsafe locking scenario: [ 42.830267] [ 42.836291] CPU0 CPU1 [ 42.840926] ---- ---- [ 42.845559] lock(ashmem_mutex); [ 42.848978] lock(&mm->mmap_sem); [ 42.855006] lock(ashmem_mutex); [ 42.860948] lock(&sb->s_type->i_mutex_key#12); [ 42.865674] [ 42.865674] *** DEADLOCK *** [ 42.865674] [ 42.871699] 1 lock held by syz-executor284/7816: [ 42.876422] #0: 000000006fa29b9a (ashmem_mutex){+.+.}, at: ashmem_shrink_scan+0xb4/0x660 [ 42.884713] [ 42.884713] stack backtrace: [ 42.889177] CPU: 1 PID: 7816 Comm: syz-executor284 Not tainted 4.20.0-rc7-next-20181224 #188 [ 42.897722] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.907046] Call Trace: [ 42.909617] dump_stack+0x1d3/0x2c6 [ 42.913237] ? dump_stack_print_info.cold.1+0x20/0x20 [ 42.918409] ? vprintk_func+0x85/0x181 [ 42.922269] print_circular_bug.isra.34.cold.58+0x1bd/0x27d [ 42.927950] ? save_trace+0xe0/0x290 [ 42.931638] __lock_acquire+0x3360/0x4c20 [ 42.935763] ? mark_held_locks+0x130/0x130 [ 42.939970] ? __switch_to_asm+0x40/0x70 [ 42.944004] ? __switch_to_asm+0x40/0x70 [ 42.948036] ? __switch_to_asm+0x34/0x70 [ 42.952068] ? __switch_to_asm+0x34/0x70 [ 42.956098] ? __switch_to_asm+0x40/0x70 [ 42.960128] ? __switch_to_asm+0x34/0x70 [ 42.964170] ? __switch_to_asm+0x40/0x70 [ 42.968201] ? __schedule+0x9e6/0x1ed0 [ 42.972065] ? __sched_text_start+0x8/0x8 [ 42.976192] ? check_preemption_disabled+0x48/0x280 [ 42.981183] ? find_held_lock+0x36/0x1c0 [ 42.985215] ? print_usage_bug+0xc0/0xc0 [ 42.989251] ? _raw_spin_unlock_irqrestore+0x82/0xd0 [ 42.994323] ? _raw_spin_unlock_irqrestore+0x82/0xd0 [ 42.999394] ? lockdep_hardirqs_on+0x421/0x5c0 [ 43.003948] ? preempt_schedule+0x4d/0x60 [ 43.008066] ? __lock_is_held+0xb5/0x140 [ 43.012098] lock_acquire+0x1ed/0x520 [ 43.015868] ? shmem_fallocate+0x18b/0x12c0 [ 43.020159] ? lock_release+0xa00/0xa00 [ 43.024102] ? arch_local_save_flags+0x40/0x40 [ 43.028669] ? mark_held_locks+0x130/0x130 [ 43.032879] down_write+0x8a/0x130 [ 43.036392] ? shmem_fallocate+0x18b/0x12c0 [ 43.040683] ? down_read+0x120/0x120 [ 43.044365] ? __lock_acquire+0x62f/0x4c20 [ 43.048572] shmem_fallocate+0x18b/0x12c0 [ 43.052691] ? mark_held_locks+0x130/0x130 [ 43.056897] ? shmem_setattr+0xda0/0xda0 [ 43.060930] ? drop_futex_key_refs.isra.15+0x6d/0xe0 [ 43.066011] ? futex_wake+0x304/0x760 [ 43.069787] ? get_futex_key+0x21b0/0x21b0 [ 43.073994] ? lock_acquire+0x1ed/0x520 [ 43.077943] ? ashmem_shrink_scan+0xb4/0x660 [ 43.082339] ? lock_downgrade+0x900/0x900 [ 43.086458] ? check_preemption_disabled+0x48/0x280 [ 43.091446] ? lock_release+0xa00/0xa00 [ 43.095390] ? refcount_sub_and_test_checked+0x203/0x310 [ 43.100809] ? refcount_dec_if_one+0x180/0x180 [ 43.105363] ? do_futex+0x249/0x26d0 [ 43.109047] ? range_alloc+0xa8/0x560 [ 43.112821] ? mutex_trylock+0x24c/0x2b0 [ 43.116854] ? ashmem_shrink_scan+0xb4/0x660 [ 43.121236] ? __ww_mutex_check_waiters+0x160/0x160 [ 43.126222] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 43.131730] ? apparmor_capable+0x355/0x6c0 [ 43.136025] ashmem_shrink_scan+0x238/0x660 [ 43.140321] ? cap_capable+0x1f9/0x260 [ 43.144183] ? ashmem_release+0x190/0x190 [ 43.148303] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 43.153822] ? ns_capable_common+0x13f/0x170 [ 43.158211] ashmem_ioctl+0x3ae/0x13a0 [ 43.162070] ? __fget+0x4d1/0x740 [ 43.165497] ? ashmem_shrink_scan+0x660/0x660 [ 43.169967] ? ksys_dup3+0x680/0x680 [ 43.173668] ? security_mmap_file+0x174/0x1b0 [ 43.178133] ? ashmem_shrink_scan+0x660/0x660 [ 43.182606] do_vfs_ioctl+0x1de/0x1790 [ 43.186467] ? ioctl_preallocate+0x300/0x300 [ 43.190850] ? __fget_light+0x2e9/0x430 [ 43.194794] ? fget_raw+0x20/0x20 [ 43.198215] ? putname+0xf2/0x130 [ 43.201648] ? __x64_sys_futex+0x476/0x690 [ 43.205855] ? do_syscall_64+0x9a/0x820 [ 43.209805] ? do_syscall_64+0x9a/0x820 [ 43.213751] ? lockdep_hardirqs_on+0x421/0x5c0 [ 43.218305] ? security_file_ioctl+0x94/0xc0 [ 43.222685] ksys_ioctl+0xa9/0xd0 [ 43.226109] __x64_sys_ioctl+0x73/0xb0 [ 43.229970] do_syscall_64+0x1b9/0x820 [ 43.233828] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 43.239341] ? syscall_return_slowpath+0x5e0/0x5e0 [ 43.244245] ? trace_hardirqs_on_caller+0x310/0x310 [ 43.249236] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 43.254224] ? recalc_sigpending_tsk+0x180/0x180 [ 43.258953] ? __switch_to_asm+0x40/0x70 [ 43.262986] ? __switch_to_asm+0x34/0x70 [ 43.267022] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 43.271839] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 43.277002] RIP: 0033:0x446ac9 [ 43.280167] Code: e8 ec be 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 ab 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 43.299046] RSP: 002b:00007ff3f354ace8 EFLAGS: 00000206 ORIG_RAX: 0000000000000010 [ 43.306725] RAX: ffffffffffffffda RBX: 00000000006ddc38 RCX: 0000000000446ac9 [ 43.313964] RDX: 0000000000000000 RSI: 000000000000770a RDI: 0000000000000004 [ 43.321204] RBP: 00000000006ddc30 R08: 0000000000000000 R09: 0000000000000000 [ 43.328569] R10: 0000000000000000 R11: 0000000000000206 R12: 00000000006ddc3c [ 43.335819] R13: 00007ffde2809c4f R14: 00007ff3f354b9c0 R15: 0000000000000001