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-5,10.128.0.58' (ECDSA) to the list of known hosts. 2017/10/01 09:37:30 parsed 1 programs 2017/10/01 09:37:30 executed programs: 0 syzkaller login: [ 45.146067] ================================================================== [ 45.153459] BUG: KASAN: use-after-free in __lock_acquire+0x407b/0x4620 [ 45.160096] Read of size 8 at addr ffff8801c88d9728 by task syz-executor7/4753 [ 45.167416] [ 45.169017] CPU: 1 PID: 4753 Comm: syz-executor7 Not tainted 4.14.0-rc2-mm1+ #11 [ 45.176515] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.185832] Call Trace: [ 45.188387] dump_stack+0x194/0x257 [ 45.191983] ? arch_local_irq_restore+0x53/0x53 [ 45.196620] ? show_regs_print_info+0x65/0x65 [ 45.201083] ? __kernel_text_address+0xd/0x40 [ 45.205542] ? __lock_acquire+0x407b/0x4620 [ 45.209831] print_address_description+0x73/0x250 [ 45.214638] ? __lock_acquire+0x407b/0x4620 [ 45.218924] kasan_report+0x25b/0x340 [ 45.222693] __asan_report_load8_noabort+0x14/0x20 [ 45.227586] __lock_acquire+0x407b/0x4620 [ 45.231700] ? unwind_dump+0x4c0/0x4c0 [ 45.235551] ? __unwind_start+0x169/0x330 [ 45.239663] ? __kernel_text_address+0xd/0x40 [ 45.244123] ? unwind_get_return_address+0x61/0xa0 [ 45.249026] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 45.254181] ? unwind_get_return_address+0x61/0xa0 [ 45.259077] ? __save_stack_trace+0x61/0xd0 [ 45.263364] ? get_signal+0x73f/0x16d0 [ 45.267215] ? save_stack_trace+0x16/0x20 [ 45.271326] ? __lock_acquire+0x20fd/0x4620 [ 45.275618] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 45.280778] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 45.285933] ? save_stack_trace+0x16/0x20 [ 45.290047] ? __lock_acquire+0x20fd/0x4620 [ 45.294332] ? osq_unlock+0x350/0x350 [ 45.298095] ? save_stack_trace+0x16/0x20 [ 45.302208] ? lock_release+0xd70/0xd70 [ 45.306147] ? check_noncircular+0x20/0x20 [ 45.310347] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 45.315504] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 45.320664] ? find_held_lock+0x39/0x1d0 [ 45.324693] ? lock_downgrade+0x990/0x990 [ 45.328806] ? check_noncircular+0x20/0x20 [ 45.333010] lock_acquire+0x1d5/0x580 [ 45.336781] ? exit_pi_state_list+0x369/0x7a0 [ 45.341242] ? lock_release+0xd70/0xd70 [ 45.345179] ? do_raw_spin_trylock+0x190/0x190 [ 45.349728] ? find_held_lock+0x39/0x1d0 [ 45.353763] _raw_spin_lock_irq+0x5e/0x80 [ 45.357874] ? exit_pi_state_list+0x369/0x7a0 [ 45.362333] exit_pi_state_list+0x369/0x7a0 [ 45.366635] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 45.372658] ? lock_release+0xd70/0xd70 [ 45.376597] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 45.382449] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 45.387517] ? __might_sleep+0x95/0x190 [ 45.391458] ? __might_fault+0x188/0x1d0 [ 45.395487] ? do_raw_spin_trylock+0x190/0x190 [ 45.400037] mm_release+0x46d/0x590 [ 45.403629] ? mm_access+0x140/0x140 [ 45.407308] ? _raw_spin_unlock_irq+0x27/0x70 [ 45.411769] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 45.416752] ? trace_hardirqs_on+0xd/0x10 [ 45.420864] ? _raw_spin_unlock_irq+0x27/0x70 [ 45.425327] ? acct_collect+0x637/0x800 [ 45.429269] do_exit+0x481/0x1b00 [ 45.432692] ? mm_update_next_owner+0x930/0x930 [ 45.437326] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 45.443178] ? find_held_lock+0x39/0x1d0 [ 45.447212] ? refill_pi_state_cache.part.6+0x2f0/0x2f0 [ 45.452540] ? check_noncircular+0x20/0x20 [ 45.456745] ? fault_in_user_writeable+0x90/0x90 [ 45.461468] ? futex_wake+0x680/0x680 [ 45.465238] ? find_held_lock+0x39/0x1d0 [ 45.469266] ? lock_downgrade+0x990/0x990 [ 45.473379] ? recalc_sigpending_tsk+0x117/0x150 [ 45.478099] ? recalc_sigpending+0x103/0x160 [ 45.482475] ? recalc_sigpending_tsk+0x150/0x150 [ 45.487193] ? get_signal+0x2b2/0x16d0 [ 45.491048] do_group_exit+0x149/0x400 [ 45.494900] ? __lock_is_held+0xbc/0x140 [ 45.498925] ? SyS_exit+0x30/0x30 [ 45.502342] ? _raw_spin_unlock_irq+0x27/0x70 [ 45.506802] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 45.511783] get_signal+0x73f/0x16d0 [ 45.515462] ? ptrace_notify+0x130/0x130 [ 45.519489] ? vma_wants_writenotify+0x3b0/0x3b0 [ 45.524212] ? exit_robust_list+0x240/0x240 [ 45.528499] ? lock_downgrade+0x990/0x990 [ 45.532613] ? SyS_brk+0x6f0/0x6f0 [ 45.536120] do_signal+0x94/0x1ee0 [ 45.539626] ? arch_get_unmapped_area+0x750/0x750 [ 45.544435] ? lock_acquire+0x1d5/0x580 [ 45.548375] ? find_held_lock+0x39/0x1d0 [ 45.552401] ? setup_sigcontext+0x7d0/0x7d0 [ 45.556690] ? lock_downgrade+0x990/0x990 [ 45.560805] ? down_write+0x120/0x120 [ 45.564572] ? lock_release+0xd70/0xd70 [ 45.568511] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 45.574360] ? vm_mmap_pgoff+0x1fc/0x280 [ 45.578386] ? exit_to_usermode_loop+0x8c/0x310 [ 45.583025] exit_to_usermode_loop+0x214/0x310 [ 45.587575] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 45.593078] ? kasan_check_write+0x14/0x20 [ 45.597278] syscall_return_slowpath+0x42f/0x510 [ 45.602003] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 45.606988] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 45.611882] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 45.616865] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 45.621586] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 45.626308] RIP: 0033:0x4520a9 [ 45.629462] RSP: 002b:00007fe81b940cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 45.637132] RAX: fffffffffffffe00 RBX: 0000000000718028 RCX: 00000000004520a9 [ 45.644366] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000718028 [ 45.651606] RBP: 0000000000718000 R08: 0000000000000000 R09: 0000000000000000 [ 45.658844] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 45.666079] R13: 00007ffd4158b7af R14: 00007fe81b9419c0 R15: 0000000000000000 [ 45.673317] [ 45.674909] Allocated by task 4779: [ 45.678504] save_stack_trace+0x16/0x20 [ 45.682440] save_stack+0x43/0xd0 [ 45.685860] kasan_kmalloc+0xad/0xe0 [ 45.689543] kmem_cache_alloc_trace+0x136/0x750 [ 45.694178] refill_pi_state_cache.part.6+0xa5/0x2f0 [ 45.699243] futex_requeue+0x1887/0x2370 [ 45.703268] do_futex+0x7f5/0x20d0 [ 45.706773] SyS_futex+0x260/0x390 [ 45.710278] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 45.714993] [ 45.716587] Freed by task 4767: [ 45.719834] save_stack_trace+0x16/0x20 [ 45.723771] save_stack+0x43/0xd0 [ 45.727187] kasan_slab_free+0x71/0xc0 [ 45.731040] kfree+0xca/0x250 [ 45.734109] put_pi_state+0x3f4/0x560 [ 45.737876] unqueue_me_pi+0x4a/0xc0 [ 45.741553] futex_wait_requeue_pi.constprop.19+0xc7f/0x1300 [ 45.747312] do_futex+0x825/0x20d0 [ 45.750818] SyS_futex+0x260/0x390 [ 45.754321] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 45.759036] [ 45.760631] The buggy address belongs to the object at ffff8801c88d9700 [ 45.760631] which belongs to the cache kmalloc-256 of size 256 [ 45.773249] The buggy address is located 40 bytes inside of [ 45.773249] 256-byte region [ffff8801c88d9700, ffff8801c88d9800) [ 45.784996] The buggy address belongs to the page: [ 45.789891] page:ffffea0007223640 count:1 mapcount:0 mapping:ffff8801c88d90c0 index:0x0 [ 45.797999] flags: 0x200000000000100(slab) [ 45.802206] raw: 0200000000000100 ffff8801c88d90c0 0000000000000000 000000010000000c [ 45.810053] raw: ffffea0007223560 ffffea0007223760 ffff8801dac007c0 0000000000000000 [ 45.817894] page dumped because: kasan: bad access detected [ 45.823565] [ 45.825159] Memory state around the buggy address: [ 45.830050] ffff8801c88d9600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 45.837372] ffff8801c88d9680: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc [ 45.844695] >ffff8801c88d9700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.852021] ^ [ 45.856659] ffff8801c88d9780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.863982] ffff8801c88d9800: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 45.871300] ================================================================== [ 45.878620] Disabling lock debugging due to kernel taint [ 45.884031] Kernel panic - not syncing: panic_on_warn set ... [ 45.884031] [ 45.891359] CPU: 1 PID: 4753 Comm: syz-executor7 Tainted: G B 4.14.0-rc2-mm1+ #11 [ 45.900067] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.909386] Call Trace: [ 45.911943] dump_stack+0x194/0x257 [ 45.915538] ? arch_local_irq_restore+0x53/0x53 [ 45.920172] ? vprintk_default+0x28/0x30 [ 45.924200] ? __lock_acquire+0x4060/0x4620 [ 45.928487] panic+0x1e4/0x41c [ 45.931645] ? refcount_error_report+0x214/0x214 [ 45.936367] ? __lock_acquire+0x407b/0x4620 [ 45.940653] kasan_end_report+0x50/0x50 [ 45.944590] kasan_report+0x144/0x340 [ 45.948356] __asan_report_load8_noabort+0x14/0x20 [ 45.953250] __lock_acquire+0x407b/0x4620 [ 45.957365] ? unwind_dump+0x4c0/0x4c0 [ 45.961216] ? __unwind_start+0x169/0x330 [ 45.965329] ? __kernel_text_address+0xd/0x40 [ 45.969790] ? unwind_get_return_address+0x61/0xa0 [ 45.974689] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 45.979840] ? unwind_get_return_address+0x61/0xa0 [ 45.984734] ? __save_stack_trace+0x61/0xd0 [ 45.989023] ? get_signal+0x73f/0x16d0 [ 45.992878] ? save_stack_trace+0x16/0x20 [ 45.996990] ? __lock_acquire+0x20fd/0x4620 [ 46.001280] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 46.006438] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 46.011591] ? save_stack_trace+0x16/0x20 [ 46.015704] ? __lock_acquire+0x20fd/0x4620 [ 46.019990] ? osq_unlock+0x350/0x350 [ 46.023758] ? save_stack_trace+0x16/0x20 [ 46.027871] ? lock_release+0xd70/0xd70 [ 46.031809] ? check_noncircular+0x20/0x20 [ 46.036014] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 46.041172] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 46.046330] ? find_held_lock+0x39/0x1d0 [ 46.050358] ? lock_downgrade+0x990/0x990 [ 46.054472] ? check_noncircular+0x20/0x20 [ 46.058672] lock_acquire+0x1d5/0x580 [ 46.062437] ? exit_pi_state_list+0x369/0x7a0 [ 46.066899] ? lock_release+0xd70/0xd70 [ 46.070837] ? do_raw_spin_trylock+0x190/0x190 [ 46.075384] ? find_held_lock+0x39/0x1d0 [ 46.079415] _raw_spin_lock_irq+0x5e/0x80 [ 46.083529] ? exit_pi_state_list+0x369/0x7a0 [ 46.087989] exit_pi_state_list+0x369/0x7a0 [ 46.092281] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 46.098306] ? lock_release+0xd70/0xd70 [ 46.102244] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 46.108092] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 46.113164] ? __might_sleep+0x95/0x190 [ 46.117106] ? __might_fault+0x188/0x1d0 [ 46.121131] ? do_raw_spin_trylock+0x190/0x190 [ 46.125680] mm_release+0x46d/0x590 [ 46.129271] ? mm_access+0x140/0x140 [ 46.132950] ? _raw_spin_unlock_irq+0x27/0x70 [ 46.137411] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 46.142392] ? trace_hardirqs_on+0xd/0x10