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-1,10.128.15.197' (ECDSA) to the list of known hosts. 2017/09/29 05:49:31 parsed 1 programs 2017/09/29 05:49:31 executed programs: 0 2017/09/29 05:49:36 executed programs: 723 syzkaller login: [ 33.964556] ================================================================== [ 33.971966] BUG: KASAN: use-after-free in __lock_acquire+0x407b/0x4620 [ 33.978617] Read of size 8 at addr ffff8801c4e35c28 by task syz-executor7/6447 [ 33.985962] [ 33.987573] CPU: 0 PID: 6447 Comm: syz-executor7 Not tainted 4.14.0-rc2-mm1+ #10 [ 33.995087] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.004421] Call Trace: [ 34.006994] dump_stack+0x194/0x257 [ 34.010609] ? arch_local_irq_restore+0x53/0x53 [ 34.015283] ? show_regs_print_info+0x65/0x65 [ 34.019761] ? __kernel_text_address+0xd/0x40 [ 34.024226] ? __lock_acquire+0x407b/0x4620 [ 34.028518] print_address_description+0x73/0x250 [ 34.033339] ? __lock_acquire+0x407b/0x4620 [ 34.037650] kasan_report+0x25b/0x340 [ 34.041435] __asan_report_load8_noabort+0x14/0x20 [ 34.046350] __lock_acquire+0x407b/0x4620 [ 34.050473] ? unwind_dump+0x4c0/0x4c0 [ 34.054327] ? __unwind_start+0x169/0x330 [ 34.058445] ? __kernel_text_address+0xd/0x40 [ 34.062918] ? unwind_get_return_address+0x61/0xa0 [ 34.067836] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 34.073001] ? unwind_get_return_address+0x61/0xa0 [ 34.077907] ? __save_stack_trace+0x61/0xd0 [ 34.082199] ? get_signal+0x73f/0x16d0 [ 34.086066] ? save_stack_trace+0x16/0x20 [ 34.090189] ? __lock_acquire+0x20fd/0x4620 [ 34.094489] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 34.099672] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 34.104845] ? save_stack_trace+0x16/0x20 [ 34.108963] ? __lock_acquire+0x20fd/0x4620 [ 34.113268] ? osq_unlock+0x350/0x350 [ 34.117053] ? save_stack_trace+0x16/0x20 [ 34.121179] ? lock_release+0xd70/0xd70 [ 34.125124] ? check_noncircular+0x20/0x20 [ 34.129331] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 34.134490] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 34.139655] ? find_held_lock+0x39/0x1d0 [ 34.143687] ? lock_downgrade+0x990/0x990 [ 34.147801] ? check_noncircular+0x20/0x20 [ 34.152007] lock_acquire+0x1d5/0x580 [ 34.155781] ? exit_pi_state_list+0x369/0x7a0 [ 34.160246] ? lock_release+0xd70/0xd70 [ 34.164193] ? do_raw_spin_trylock+0x190/0x190 [ 34.168745] ? find_held_lock+0x39/0x1d0 [ 34.172784] _raw_spin_lock_irq+0x5e/0x80 [ 34.176898] ? exit_pi_state_list+0x369/0x7a0 [ 34.181360] exit_pi_state_list+0x369/0x7a0 [ 34.185657] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 34.191683] ? lock_release+0xd70/0xd70 [ 34.195625] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 34.201478] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 34.206550] ? __might_sleep+0x95/0x190 [ 34.210493] ? __might_fault+0x188/0x1d0 [ 34.214525] ? do_raw_spin_trylock+0x190/0x190 [ 34.219075] mm_release+0x46d/0x590 [ 34.222666] ? do_raw_spin_trylock+0x190/0x190 [ 34.227215] ? mm_access+0x140/0x140 [ 34.230897] ? _raw_spin_unlock_irq+0x27/0x70 [ 34.235361] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 34.240345] ? trace_hardirqs_on+0xd/0x10 [ 34.244461] ? _raw_spin_unlock_irq+0x27/0x70 [ 34.248922] ? acct_collect+0x637/0x800 [ 34.252865] do_exit+0x481/0x1b00 [ 34.256287] ? mm_update_next_owner+0x930/0x930 [ 34.260925] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 34.266778] ? find_held_lock+0x39/0x1d0 [ 34.270810] ? refill_pi_state_cache.part.6+0x2f0/0x2f0 [ 34.276142] ? check_noncircular+0x20/0x20 [ 34.280347] ? fault_in_user_writeable+0x90/0x90 [ 34.285072] ? futex_wake+0x680/0x680 [ 34.288843] ? find_held_lock+0x39/0x1d0 [ 34.292875] ? lock_downgrade+0x990/0x990 [ 34.296991] ? recalc_sigpending_tsk+0x117/0x150 [ 34.301718] ? recalc_sigpending+0x103/0x160 [ 34.306094] ? recalc_sigpending_tsk+0x150/0x150 [ 34.310818] ? get_signal+0x2b2/0x16d0 [ 34.314675] do_group_exit+0x149/0x400 [ 34.318533] ? __lock_is_held+0xbc/0x140 [ 34.322559] ? SyS_exit+0x30/0x30 [ 34.325981] ? _raw_spin_unlock_irq+0x27/0x70 [ 34.330445] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 34.335438] get_signal+0x73f/0x16d0 [ 34.339123] ? ptrace_notify+0x130/0x130 [ 34.343157] ? __schedule+0x8f0/0x2070 [ 34.347030] ? exit_robust_list+0x240/0x240 [ 34.351323] ? lock_downgrade+0x990/0x990 [ 34.355438] ? SyS_brk+0x6f0/0x6f0 [ 34.358947] do_signal+0x94/0x1ee0 [ 34.362455] ? arch_get_unmapped_area+0x750/0x750 [ 34.367264] ? lock_acquire+0x1d5/0x580 [ 34.371206] ? find_held_lock+0x39/0x1d0 [ 34.375252] ? setup_sigcontext+0x7d0/0x7d0 [ 34.379553] ? lock_downgrade+0x990/0x990 [ 34.383671] ? down_write+0x120/0x120 [ 34.387441] ? lock_release+0xd70/0xd70 [ 34.391384] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 34.397254] ? vm_mmap_pgoff+0x1fc/0x280 [ 34.401292] ? exit_to_usermode_loop+0x8c/0x310 [ 34.405942] exit_to_usermode_loop+0x214/0x310 [ 34.410493] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 34.415998] ? kasan_check_write+0x14/0x20 [ 34.420207] syscall_return_slowpath+0x42f/0x510 [ 34.424931] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 34.429926] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 34.434824] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 34.439812] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 34.444537] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 34.449261] RIP: 0033:0x4520a9 [ 34.452419] RSP: 002b:00007f58e8a12cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 34.460094] RAX: fffffffffffffe00 RBX: 0000000000718028 RCX: 00000000004520a9 [ 34.467343] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000718028 [ 34.474579] RBP: 0000000000718000 R08: 0000000000000000 R09: 0000000000000000 [ 34.481816] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 34.489064] R13: 00007ffc66b367af R14: 00007f58e8a139c0 R15: 0000000000000000 [ 34.496317] [ 34.497912] Allocated by task 6476: [ 34.501510] save_stack_trace+0x16/0x20 [ 34.505453] save_stack+0x43/0xd0 [ 34.508873] kasan_kmalloc+0xad/0xe0 [ 34.512554] kmem_cache_alloc_trace+0x136/0x750 [ 34.517188] refill_pi_state_cache.part.6+0xa5/0x2f0 [ 34.522257] futex_requeue+0x1887/0x2370 [ 34.526285] do_futex+0x7f5/0x20d0 [ 34.529792] SyS_futex+0x260/0x390 [ 34.533301] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 34.538024] [ 34.539621] Freed by task 6461: [ 34.542867] save_stack_trace+0x16/0x20 [ 34.546806] save_stack+0x43/0xd0 [ 34.550234] kasan_slab_free+0x71/0xc0 [ 34.554086] kfree+0xca/0x250 [ 34.557158] put_pi_state+0x3f4/0x560 [ 34.561026] unqueue_me_pi+0x4a/0xc0 [ 34.564709] futex_wait_requeue_pi.constprop.19+0xc7f/0x1300 [ 34.570472] do_futex+0x825/0x20d0 [ 34.573979] SyS_futex+0x260/0x390 [ 34.577497] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 34.582216] [ 34.583827] The buggy address belongs to the object at ffff8801c4e35c00 [ 34.583827] which belongs to the cache kmalloc-256 of size 256 [ 34.596462] The buggy address is located 40 bytes inside of [ 34.596462] 256-byte region [ffff8801c4e35c00, ffff8801c4e35d00) [ 34.608222] The buggy address belongs to the page: [ 34.613118] page:ffffea0007138d40 count:1 mapcount:0 mapping:ffff8801c4e350c0 index:0x0 [ 34.621231] flags: 0x200000000000100(slab) [ 34.625435] raw: 0200000000000100 ffff8801c4e350c0 0000000000000000 000000010000000c [ 34.633284] raw: ffffea0007147720 ffffea0007138ca0 ffff8801dac007c0 0000000000000000 [ 34.641129] page dumped because: kasan: bad access detected [ 34.646802] [ 34.648397] Memory state around the buggy address: [ 34.653292] ffff8801c4e35b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 34.660617] ffff8801c4e35b80: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc [ 34.667942] >ffff8801c4e35c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.675267] ^ [ 34.679900] ffff8801c4e35c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.687227] ffff8801c4e35d00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 34.694559] ================================================================== [ 34.701882] Disabling lock debugging due to kernel taint [ 34.707297] Kernel panic - not syncing: panic_on_warn set ... [ 34.707297] [ 34.714628] CPU: 0 PID: 6447 Comm: syz-executor7 Tainted: G B 4.14.0-rc2-mm1+ #10 [ 34.723343] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.732664] Call Trace: [ 34.735227] dump_stack+0x194/0x257 [ 34.738822] ? arch_local_irq_restore+0x53/0x53 [ 34.743459] ? vprintk_default+0x28/0x30 [ 34.747490] ? __lock_acquire+0x4020/0x4620 [ 34.751782] panic+0x1e4/0x417 [ 34.754941] ? __warn+0x1d9/0x1d9 [ 34.758369] ? __lock_acquire+0x407b/0x4620 [ 34.762659] kasan_end_report+0x50/0x50 [ 34.766601] kasan_report+0x144/0x340 [ 34.770370] __asan_report_load8_noabort+0x14/0x20 [ 34.775276] __lock_acquire+0x407b/0x4620 [ 34.779393] ? unwind_dump+0x4c0/0x4c0 [ 34.783248] ? __unwind_start+0x169/0x330 [ 34.787386] ? __kernel_text_address+0xd/0x40 [ 34.791850] ? unwind_get_return_address+0x61/0xa0 [ 34.796749] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 34.801907] ? unwind_get_return_address+0x61/0xa0 [ 34.806803] ? __save_stack_trace+0x61/0xd0 [ 34.811093] ? get_signal+0x73f/0x16d0 [ 34.814948] ? save_stack_trace+0x16/0x20 [ 34.819062] ? __lock_acquire+0x20fd/0x4620 [ 34.823353] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 34.828517] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 34.833675] ? save_stack_trace+0x16/0x20 [ 34.837790] ? __lock_acquire+0x20fd/0x4620 [ 34.842078] ? osq_unlock+0x350/0x350 [ 34.845844] ? save_stack_trace+0x16/0x20 [ 34.849963] ? lock_release+0xd70/0xd70 [ 34.853904] ? check_noncircular+0x20/0x20 [ 34.858119] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 34.863285] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 34.868447] ? find_held_lock+0x39/0x1d0 [ 34.872481] ? lock_downgrade+0x990/0x990 [ 34.876596] ? check_noncircular+0x20/0x20 [ 34.880800] lock_acquire+0x1d5/0x580 [ 34.884569] ? exit_pi_state_list+0x369/0x7a0 [ 34.889037] ? lock_release+0xd70/0xd70 [ 34.892977] ? do_raw_spin_trylock+0x190/0x190 [ 34.897527] ? find_held_lock+0x39/0x1d0 [ 34.901574] _raw_spin_lock_irq+0x5e/0x80 [ 34.905688] ? exit_pi_state_list+0x369/0x7a0 [ 34.910152] exit_pi_state_list+0x369/0x7a0 [ 34.914444] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 34.920472] ? lock_release+0xd70/0xd70 [ 34.924426] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 34.930276] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 34.935349] ? __might_sleep+0x95/0x190 [ 34.939297] ? __might_fault+0x188/0x1d0 [ 34.943329] ? do_raw_spin_trylock+0x190/0x190 [ 34.947882] mm_release+0x46d/0x590 [ 34.951475] ? do_raw_spin_trylock+0x190/0x190 [ 34.956026] ? mm_access+0x140/0x140 [ 34.959707] ? _raw_spin_unlock_irq+0x27/0x70 [ 34.964171] ? trace_hardirqs_on_caller+0x421/0x5c0