INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] 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. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added 'ci-upstream-mmots-kasan-gce-7,10.128.15.221' (ECDSA) to the list of known hosts. 2017/10/01 21:13:06 parsed 1 programs 2017/10/01 21:13:06 executed programs: 0 syzkaller login: [ 35.533241] ================================================================== [ 35.540646] BUG: KASAN: use-after-free in __lock_acquire+0x407b/0x4620 [ 35.547297] Read of size 8 at addr ffff8801cb4d87e8 by task syz-executor1/4606 [ 35.554629] [ 35.556236] CPU: 0 PID: 4606 Comm: syz-executor1 Not tainted 4.14.0-rc2-mm1+ #11 [ 35.563744] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.573075] Call Trace: [ 35.575641] dump_stack+0x194/0x257 [ 35.579254] ? arch_local_irq_restore+0x53/0x53 [ 35.583903] ? show_regs_print_info+0x65/0x65 [ 35.588383] ? __kernel_text_address+0xd/0x40 [ 35.592855] ? __lock_acquire+0x407b/0x4620 [ 35.597147] print_address_description+0x73/0x250 [ 35.601964] ? __lock_acquire+0x407b/0x4620 [ 35.606270] kasan_report+0x25b/0x340 [ 35.610050] __asan_report_load8_noabort+0x14/0x20 [ 35.614960] __lock_acquire+0x407b/0x4620 [ 35.619088] ? unwind_dump+0x4c0/0x4c0 [ 35.622950] ? __unwind_start+0x169/0x330 [ 35.627075] ? __kernel_text_address+0xd/0x40 [ 35.631550] ? unwind_get_return_address+0x61/0xa0 [ 35.636456] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.641619] ? unwind_get_return_address+0x61/0xa0 [ 35.646624] ? __save_stack_trace+0x61/0xd0 [ 35.650913] ? get_signal+0x73f/0x16d0 [ 35.654781] ? save_stack_trace+0x16/0x20 [ 35.658910] ? __lock_acquire+0x20fd/0x4620 [ 35.663202] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.668372] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.673537] ? save_stack_trace+0x16/0x20 [ 35.677655] ? __lock_acquire+0x20fd/0x4620 [ 35.681950] ? osq_unlock+0x350/0x350 [ 35.685730] ? save_stack_trace+0x16/0x20 [ 35.689864] ? lock_release+0xd70/0xd70 [ 35.693939] ? check_noncircular+0x20/0x20 [ 35.698143] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.703319] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.708514] ? find_held_lock+0x39/0x1d0 [ 35.712560] ? lock_downgrade+0x990/0x990 [ 35.716676] ? check_noncircular+0x20/0x20 [ 35.720877] lock_acquire+0x1d5/0x580 [ 35.724647] ? exit_pi_state_list+0x369/0x7a0 [ 35.729123] ? lock_release+0xd70/0xd70 [ 35.733074] ? do_raw_spin_trylock+0x190/0x190 [ 35.737634] ? find_held_lock+0x39/0x1d0 [ 35.741675] _raw_spin_lock_irq+0x5e/0x80 [ 35.745793] ? exit_pi_state_list+0x369/0x7a0 [ 35.750253] exit_pi_state_list+0x369/0x7a0 [ 35.754554] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 35.760592] ? lock_release+0xd70/0xd70 [ 35.764535] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 35.770395] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 35.775475] ? __might_sleep+0x95/0x190 [ 35.779438] ? __might_fault+0x188/0x1d0 [ 35.783470] ? do_raw_spin_trylock+0x190/0x190 [ 35.788038] mm_release+0x46d/0x590 [ 35.791639] ? do_raw_spin_trylock+0x190/0x190 [ 35.796188] ? mm_access+0x140/0x140 [ 35.799871] ? _raw_spin_unlock_irq+0x27/0x70 [ 35.804334] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 35.809320] ? trace_hardirqs_on+0xd/0x10 [ 35.813440] ? _raw_spin_unlock_irq+0x27/0x70 [ 35.817903] ? acct_collect+0x637/0x800 [ 35.821846] do_exit+0x481/0x1b00 [ 35.825267] ? mm_update_next_owner+0x930/0x930 [ 35.829902] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 35.835755] ? find_held_lock+0x39/0x1d0 [ 35.839785] ? refill_pi_state_cache.part.6+0x2f0/0x2f0 [ 35.845117] ? check_noncircular+0x20/0x20 [ 35.849319] ? fault_in_user_writeable+0x90/0x90 [ 35.854046] ? futex_wake+0x680/0x680 [ 35.857818] ? find_held_lock+0x39/0x1d0 [ 35.861853] ? lock_downgrade+0x990/0x990 [ 35.865971] ? recalc_sigpending_tsk+0x117/0x150 [ 35.870694] ? recalc_sigpending+0x103/0x160 [ 35.875071] ? recalc_sigpending_tsk+0x150/0x150 [ 35.879791] ? get_signal+0x2b2/0x16d0 [ 35.883649] do_group_exit+0x149/0x400 [ 35.887507] ? __lock_is_held+0xbc/0x140 [ 35.891539] ? SyS_exit+0x30/0x30 [ 35.894959] ? _raw_spin_unlock_irq+0x27/0x70 [ 35.899426] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 35.904411] get_signal+0x73f/0x16d0 [ 35.908093] ? ptrace_notify+0x130/0x130 [ 35.912123] ? __schedule+0x8f0/0x2070 [ 35.915992] ? exit_robust_list+0x240/0x240 [ 35.920288] ? lock_downgrade+0x990/0x990 [ 35.924403] ? SyS_brk+0x6f0/0x6f0 [ 35.927912] do_signal+0x94/0x1ee0 [ 35.931420] ? arch_get_unmapped_area+0x750/0x750 [ 35.936228] ? lock_acquire+0x1d5/0x580 [ 35.940171] ? find_held_lock+0x39/0x1d0 [ 35.944199] ? setup_sigcontext+0x7d0/0x7d0 [ 35.948488] ? lock_downgrade+0x990/0x990 [ 35.952604] ? down_write+0x120/0x120 [ 35.956371] ? lock_release+0xd70/0xd70 [ 35.960312] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 35.966163] ? vm_mmap_pgoff+0x1fc/0x280 [ 35.970190] ? exit_to_usermode_loop+0x8c/0x310 [ 35.974825] exit_to_usermode_loop+0x214/0x310 [ 35.979372] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 35.984875] ? kasan_check_write+0x14/0x20 [ 35.989079] syscall_return_slowpath+0x42f/0x510 [ 35.994765] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 35.999756] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 36.004657] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 36.009648] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 36.015301] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 36.020033] RIP: 0033:0x4520a9 [ 36.023193] RSP: 002b:00007f3d3ac49cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 36.030871] RAX: fffffffffffffe00 RBX: 0000000000718028 RCX: 00000000004520a9 [ 36.038370] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000718028 [ 36.045616] RBP: 0000000000718000 R08: 0000000000000000 R09: 0000000000000000 [ 36.052853] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 36.060092] R13: 00007ffdd026d8df R14: 00007f3d3ac4a9c0 R15: 0000000000000000 [ 36.067362] [ 36.068963] Allocated by task 4632: [ 36.072559] save_stack_trace+0x16/0x20 [ 36.076500] save_stack+0x43/0xd0 [ 36.079916] kasan_kmalloc+0xad/0xe0 [ 36.083593] kmem_cache_alloc_trace+0x136/0x750 [ 36.088226] refill_pi_state_cache.part.6+0xa5/0x2f0 [ 36.093292] futex_requeue+0x1887/0x2370 [ 36.097316] do_futex+0x7f5/0x20d0 [ 36.100821] SyS_futex+0x260/0x390 [ 36.104327] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 36.109047] [ 36.110640] Freed by task 4614: [ 36.113884] save_stack_trace+0x16/0x20 [ 36.117832] save_stack+0x43/0xd0 [ 36.121247] kasan_slab_free+0x71/0xc0 [ 36.125098] kfree+0xca/0x250 [ 36.128168] put_pi_state+0x3f4/0x560 [ 36.131933] unqueue_me_pi+0x4a/0xc0 [ 36.135609] futex_wait_requeue_pi.constprop.19+0xc7f/0x1300 [ 36.141371] do_futex+0x825/0x20d0 [ 36.144875] SyS_futex+0x260/0x390 [ 36.148378] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 36.153097] [ 36.154689] The buggy address belongs to the object at ffff8801cb4d87c0 [ 36.154689] which belongs to the cache kmalloc-256 of size 256 [ 36.167305] The buggy address is located 40 bytes inside of [ 36.167305] 256-byte region [ffff8801cb4d87c0, ffff8801cb4d88c0) [ 36.179052] The buggy address belongs to the page: [ 36.183945] page:ffffea00072d3600 count:1 mapcount:0 mapping:ffff8801cb4d8040 index:0x0 [ 36.192399] flags: 0x200000000000100(slab) [ 36.196605] raw: 0200000000000100 ffff8801cb4d8040 0000000000000000 000000010000000c [ 36.204450] raw: ffffea00072429e0 ffffea00072384a0 ffff8801dac007c0 0000000000000000 [ 36.212292] page dumped because: kasan: bad access detected [ 36.217961] [ 36.219553] Memory state around the buggy address: [ 36.224444] ffff8801cb4d8680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 36.231765] ffff8801cb4d8700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 36.239085] >ffff8801cb4d8780: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 36.246404] ^ [ 36.253119] ffff8801cb4d8800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 36.260440] ffff8801cb4d8880: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 36.267759] ================================================================== [ 36.275082] Disabling lock debugging due to kernel taint [ 36.280493] Kernel panic - not syncing: panic_on_warn set ... [ 36.280493] [ 36.287818] CPU: 0 PID: 4606 Comm: syz-executor1 Tainted: G B 4.14.0-rc2-mm1+ #11 [ 36.296526] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 36.305841] Call Trace: [ 36.308414] dump_stack+0x194/0x257 [ 36.312015] ? arch_local_irq_restore+0x53/0x53 [ 36.316651] ? vprintk_default+0x28/0x30 [ 36.320675] ? __lock_acquire+0x4060/0x4620 [ 36.324964] panic+0x1e4/0x41c [ 36.328122] ? refcount_error_report+0x214/0x214 [ 36.332848] ? __lock_acquire+0x407b/0x4620 [ 36.337134] kasan_end_report+0x50/0x50 [ 36.341072] kasan_report+0x144/0x340 [ 36.344835] __asan_report_load8_noabort+0x14/0x20 [ 36.349726] __lock_acquire+0x407b/0x4620 [ 36.353838] ? unwind_dump+0x4c0/0x4c0 [ 36.357689] ? __unwind_start+0x169/0x330 [ 36.361802] ? __kernel_text_address+0xd/0x40 [ 36.366259] ? unwind_get_return_address+0x61/0xa0 [ 36.371154] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 36.376305] ? unwind_get_return_address+0x61/0xa0 [ 36.381197] ? __save_stack_trace+0x61/0xd0 [ 36.385483] ? get_signal+0x73f/0x16d0 [ 36.389333] ? save_stack_trace+0x16/0x20 [ 36.393443] ? __lock_acquire+0x20fd/0x4620 [ 36.397732] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 36.402888] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 36.408044] ? save_stack_trace+0x16/0x20 [ 36.412157] ? __lock_acquire+0x20fd/0x4620 [ 36.416444] ? osq_unlock+0x350/0x350 [ 36.420206] ? save_stack_trace+0x16/0x20 [ 36.424321] ? lock_release+0xd70/0xd70 [ 36.428258] ? check_noncircular+0x20/0x20 [ 36.432456] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 36.437608] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 36.442763] ? find_held_lock+0x39/0x1d0 [ 36.446789] ? lock_downgrade+0x990/0x990 [ 36.450899] ? check_noncircular+0x20/0x20 [ 36.455098] lock_acquire+0x1d5/0x580 [ 36.458862] ? exit_pi_state_list+0x369/0x7a0 [ 36.463322] ? lock_release+0xd70/0xd70 [ 36.467260] ? do_raw_spin_trylock+0x190/0x190 [ 36.471804] ? find_held_lock+0x39/0x1d0 [ 36.475833] _raw_spin_lock_irq+0x5e/0x80 [ 36.479945] ? exit_pi_state_list+0x369/0x7a0 [ 36.484402] exit_pi_state_list+0x369/0x7a0 [ 36.488688] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 36.494710] ? lock_release+0xd70/0xd70 [ 36.498646] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 36.504496] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 36.509563] ? __might_sleep+0x95/0x190 [ 36.513502] ? __might_fault+0x188/0x1d0 [ 36.517526] ? do_raw_spin_trylock+0x190/0x190 [ 36.522073] mm_release+0x46d/0x590 [ 36.525662] ? do_raw_spin_trylock+0x190/0x190 [ 36.530208] ? mm_access+0x140/0x140