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-1,10.128.15.213' (ECDSA) to the list of known hosts. 2017/09/30 12:52:00 parsed 1 programs 2017/09/30 12:52:00 executed programs: 0 syzkaller login: [ 34.892616] ================================================================== [ 34.900020] BUG: KASAN: use-after-free in __lock_acquire+0x407b/0x4620 [ 34.906667] Read of size 8 at addr ffff8801c9ae8028 by task syz-executor1/4963 [ 34.913998] [ 34.915600] CPU: 1 PID: 4963 Comm: syz-executor1 Not tainted 4.14.0-rc2-mm1+ #11 [ 34.923099] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.932430] Call Trace: [ 34.935000] dump_stack+0x194/0x257 [ 34.938610] ? arch_local_irq_restore+0x53/0x53 [ 34.943258] ? show_regs_print_info+0x65/0x65 [ 34.947735] ? __kernel_text_address+0xd/0x40 [ 34.952214] ? __lock_acquire+0x407b/0x4620 [ 34.956518] print_address_description+0x73/0x250 [ 34.961344] ? __lock_acquire+0x407b/0x4620 [ 34.965646] kasan_report+0x25b/0x340 [ 34.969427] __asan_report_load8_noabort+0x14/0x20 [ 34.974338] __lock_acquire+0x407b/0x4620 [ 34.978462] ? unwind_dump+0x4c0/0x4c0 [ 34.982318] ? __unwind_start+0x169/0x330 [ 34.986436] ? __kernel_text_address+0xd/0x40 [ 34.990898] ? unwind_get_return_address+0x61/0xa0 [ 34.995801] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.000959] ? unwind_get_return_address+0x61/0xa0 [ 35.005854] ? __save_stack_trace+0x61/0xd0 [ 35.010149] ? get_signal+0x73f/0x16d0 [ 35.014007] ? save_stack_trace+0x16/0x20 [ 35.018128] ? __lock_acquire+0x20fd/0x4620 [ 35.022419] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.027578] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.032731] ? save_stack_trace+0x16/0x20 [ 35.036845] ? __lock_acquire+0x20fd/0x4620 [ 35.041132] ? osq_unlock+0x350/0x350 [ 35.044896] ? save_stack_trace+0x16/0x20 [ 35.049011] ? check_noncircular+0x20/0x20 [ 35.053219] ? check_noncircular+0x20/0x20 [ 35.057427] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.062597] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.067759] ? __lock_is_held+0xbc/0x140 [ 35.071788] ? find_held_lock+0x39/0x1d0 [ 35.075830] ? lock_downgrade+0x990/0x990 [ 35.079947] ? check_noncircular+0x20/0x20 [ 35.084145] lock_acquire+0x1d5/0x580 [ 35.087916] ? exit_pi_state_list+0x369/0x7a0 [ 35.092387] ? lock_release+0xd70/0xd70 [ 35.096326] ? do_raw_spin_trylock+0x190/0x190 [ 35.100870] ? find_held_lock+0x39/0x1d0 [ 35.104911] _raw_spin_lock_irq+0x5e/0x80 [ 35.109032] ? exit_pi_state_list+0x369/0x7a0 [ 35.113498] exit_pi_state_list+0x369/0x7a0 [ 35.117794] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 35.123822] ? lock_release+0xd70/0xd70 [ 35.127763] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 35.133616] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 35.138695] ? __might_sleep+0x95/0x190 [ 35.142640] ? __might_fault+0x188/0x1d0 [ 35.146673] ? do_raw_spin_trylock+0x190/0x190 [ 35.151227] mm_release+0x46d/0x590 [ 35.154818] ? do_raw_spin_trylock+0x190/0x190 [ 35.159365] ? mm_access+0x140/0x140 [ 35.163048] ? _raw_spin_unlock_irq+0x27/0x70 [ 35.167518] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 35.172502] ? trace_hardirqs_on+0xd/0x10 [ 35.176619] ? _raw_spin_unlock_irq+0x27/0x70 [ 35.181082] ? acct_collect+0x637/0x800 [ 35.185028] do_exit+0x481/0x1b00 [ 35.188450] ? mm_update_next_owner+0x930/0x930 [ 35.193090] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 35.198946] ? rcu_note_context_switch+0x710/0x710 [ 35.203842] ? futex_wait_setup+0x14a/0x3d0 [ 35.208140] ? __might_sleep+0x95/0x190 [ 35.212084] ? osq_unlock+0x350/0x350 [ 35.215850] ? futex_wait_queue_me+0x524/0x7e0 [ 35.220400] ? refill_pi_state_cache.part.6+0x2f0/0x2f0 [ 35.225732] ? memset+0x31/0x40 [ 35.228976] ? check_noncircular+0x20/0x20 [ 35.233183] ? futex_wait_setup+0x22e/0x3d0 [ 35.237479] ? futex_wake+0x680/0x680 [ 35.241251] ? retint_kernel+0x10/0x10 [ 35.245101] ? find_held_lock+0x39/0x1d0 [ 35.249131] ? lock_downgrade+0x990/0x990 [ 35.253246] ? recalc_sigpending_tsk+0x117/0x150 [ 35.257970] ? recalc_sigpending+0x103/0x160 [ 35.262345] ? recalc_sigpending_tsk+0x150/0x150 [ 35.267067] ? get_signal+0x2b2/0x16d0 [ 35.270922] do_group_exit+0x149/0x400 [ 35.274776] ? __lock_is_held+0xbc/0x140 [ 35.278806] ? SyS_exit+0x30/0x30 [ 35.282234] ? _raw_spin_unlock_irq+0x27/0x70 [ 35.286700] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 35.291687] get_signal+0x73f/0x16d0 [ 35.295373] ? ptrace_notify+0x130/0x130 [ 35.299403] ? vma_wants_writenotify+0x3b0/0x3b0 [ 35.304131] ? exit_robust_list+0x240/0x240 [ 35.308426] ? lock_downgrade+0x990/0x990 [ 35.312543] ? SyS_brk+0x6f0/0x6f0 [ 35.316051] do_signal+0x94/0x1ee0 [ 35.319560] ? arch_get_unmapped_area+0x750/0x750 [ 35.324367] ? lock_acquire+0x1d5/0x580 [ 35.328313] ? find_held_lock+0x39/0x1d0 [ 35.332347] ? setup_sigcontext+0x7d0/0x7d0 [ 35.336632] ? lock_downgrade+0x990/0x990 [ 35.340746] ? down_write+0x120/0x120 [ 35.344519] ? lock_release+0xd70/0xd70 [ 35.348467] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 35.354322] ? vm_mmap_pgoff+0x1fc/0x280 [ 35.358351] ? exit_to_usermode_loop+0x8c/0x310 [ 35.362991] exit_to_usermode_loop+0x214/0x310 [ 35.367541] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 35.373044] ? kasan_check_write+0x14/0x20 [ 35.377258] syscall_return_slowpath+0x42f/0x510 [ 35.381981] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 35.386964] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 35.391866] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 35.396858] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 35.401588] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 35.406308] RIP: 0033:0x4520a9 [ 35.409466] RSP: 002b:00007f5152fd4cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 35.417140] RAX: 0000000000000000 RBX: 0000000000718188 RCX: 00000000004520a9 [ 35.424382] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000718188 [ 35.431622] RBP: 0000000000718160 R08: 0000000000000000 R09: 0000000000000000 [ 35.438870] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 35.446122] R13: 0000000000a6f7ef R14: 00007f5152fd59c0 R15: 000000000000000a [ 35.453377] [ 35.454980] Allocated by task 4976: [ 35.458586] save_stack_trace+0x16/0x20 [ 35.462538] save_stack+0x43/0xd0 [ 35.465970] kasan_kmalloc+0xad/0xe0 [ 35.470393] kmem_cache_alloc_trace+0x136/0x750 [ 35.475045] refill_pi_state_cache.part.6+0xa5/0x2f0 [ 35.480127] futex_requeue+0x1887/0x2370 [ 35.484163] do_futex+0x7f5/0x20d0 [ 35.487674] SyS_futex+0x260/0x390 [ 35.491192] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 35.495910] [ 35.497508] Freed by task 4950: [ 35.500765] save_stack_trace+0x16/0x20 [ 35.504727] save_stack+0x43/0xd0 [ 35.508193] kasan_slab_free+0x71/0xc0 [ 35.512060] kfree+0xca/0x250 [ 35.515145] put_pi_state+0x3f4/0x560 [ 35.518920] unqueue_me_pi+0x4a/0xc0 [ 35.522609] futex_wait_requeue_pi.constprop.19+0xc7f/0x1300 [ 35.528382] do_futex+0x825/0x20d0 [ 35.531900] SyS_futex+0x260/0x390 [ 35.535422] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 35.540147] [ 35.541753] The buggy address belongs to the object at ffff8801c9ae8000 [ 35.541753] which belongs to the cache kmalloc-256 of size 256 [ 35.554402] The buggy address is located 40 bytes inside of [ 35.554402] 256-byte region [ffff8801c9ae8000, ffff8801c9ae8100) [ 35.566168] The buggy address belongs to the page: [ 35.571075] page:ffffea000726ba00 count:1 mapcount:0 mapping:ffff8801c9ae8000 index:0xffff8801c9ae8dc0 [ 35.580494] flags: 0x200000000000100(slab) [ 35.584699] raw: 0200000000000100 ffff8801c9ae8000 ffff8801c9ae8dc0 0000000100000006 [ 35.592560] raw: ffffea000726c320 ffffea000725a560 ffff8801dac007c0 0000000000000000 [ 35.600414] page dumped because: kasan: bad access detected [ 35.606096] [ 35.607689] Memory state around the buggy address: [ 35.612585] ffff8801c9ae7f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc [ 35.619913] ffff8801c9ae7f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 35.627246] >ffff8801c9ae8000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 35.634574] ^ [ 35.639207] ffff8801c9ae8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 35.646538] ffff8801c9ae8100: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 35.653869] ================================================================== [ 35.661200] Disabling lock debugging due to kernel taint [ 35.666615] Kernel panic - not syncing: panic_on_warn set ... [ 35.666615] [ 35.673942] CPU: 1 PID: 4963 Comm: syz-executor1 Tainted: G B 4.14.0-rc2-mm1+ #11 [ 35.682653] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.691969] Call Trace: [ 35.694524] dump_stack+0x194/0x257 [ 35.698119] ? arch_local_irq_restore+0x53/0x53 [ 35.702752] ? vprintk_default+0x28/0x30 [ 35.706782] ? __lock_acquire+0x4060/0x4620 [ 35.711069] panic+0x1e4/0x41c [ 35.714226] ? refcount_error_report+0x214/0x214 [ 35.718950] ? __lock_acquire+0x407b/0x4620 [ 35.723238] kasan_end_report+0x50/0x50 [ 35.727176] kasan_report+0x144/0x340 [ 35.730941] __asan_report_load8_noabort+0x14/0x20 [ 35.735835] __lock_acquire+0x407b/0x4620 [ 35.739947] ? unwind_dump+0x4c0/0x4c0 [ 35.743797] ? __unwind_start+0x169/0x330 [ 35.747910] ? __kernel_text_address+0xd/0x40 [ 35.752368] ? unwind_get_return_address+0x61/0xa0 [ 35.757266] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.762419] ? unwind_get_return_address+0x61/0xa0 [ 35.767313] ? __save_stack_trace+0x61/0xd0 [ 35.771602] ? get_signal+0x73f/0x16d0 [ 35.775456] ? save_stack_trace+0x16/0x20 [ 35.779567] ? __lock_acquire+0x20fd/0x4620 [ 35.783854] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.789014] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.794168] ? save_stack_trace+0x16/0x20 [ 35.798279] ? __lock_acquire+0x20fd/0x4620 [ 35.802563] ? osq_unlock+0x350/0x350 [ 35.806328] ? save_stack_trace+0x16/0x20 [ 35.810440] ? check_noncircular+0x20/0x20 [ 35.814640] ? check_noncircular+0x20/0x20 [ 35.818842] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.823996] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.829155] ? __lock_is_held+0xbc/0x140 [ 35.833182] ? find_held_lock+0x39/0x1d0 [ 35.837211] ? lock_downgrade+0x990/0x990 [ 35.841326] ? check_noncircular+0x20/0x20 [ 35.845523] lock_acquire+0x1d5/0x580 [ 35.849290] ? exit_pi_state_list+0x369/0x7a0 [ 35.853753] ? lock_release+0xd70/0xd70 [ 35.857691] ? do_raw_spin_trylock+0x190/0x190 [ 35.862236] ? find_held_lock+0x39/0x1d0 [ 35.866265] _raw_spin_lock_irq+0x5e/0x80 [ 35.870376] ? exit_pi_state_list+0x369/0x7a0 [ 35.874835] exit_pi_state_list+0x369/0x7a0 [ 35.879124] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 35.885146] ? lock_release+0xd70/0xd70 [ 35.889087] ? trace_event_raw_event_sched_switch+0x770/0x770