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-9,10.128.0.50' (ECDSA) to the list of known hosts. 2017/09/29 23:00:30 parsed 1 programs 2017/09/29 23:00:30 executed programs: 0 syzkaller login: [ 37.491748] ================================================================== [ 37.499165] BUG: KASAN: use-after-free in __lock_acquire+0x407b/0x4620 [ 37.505796] Read of size 8 at addr ffff8801ccada828 by task syz-executor4/3556 [ 37.513117] [ 37.514715] CPU: 0 PID: 3556 Comm: syz-executor4 Not tainted 4.14.0-rc2-mm1+ #10 [ 37.522211] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 37.531528] Call Trace: [ 37.534083] dump_stack+0x194/0x257 [ 37.537678] ? arch_local_irq_restore+0x53/0x53 [ 37.542313] ? show_regs_print_info+0x65/0x65 [ 37.546774] ? __kernel_text_address+0xd/0x40 [ 37.551234] ? __lock_acquire+0x407b/0x4620 [ 37.555522] print_address_description+0x73/0x250 [ 37.560332] ? __lock_acquire+0x407b/0x4620 [ 37.564618] kasan_report+0x25b/0x340 [ 37.568400] __asan_report_load8_noabort+0x14/0x20 [ 37.573294] __lock_acquire+0x407b/0x4620 [ 37.577407] ? unwind_dump+0x4c0/0x4c0 [ 37.581257] ? __unwind_start+0x169/0x330 [ 37.585369] ? __kernel_text_address+0xd/0x40 [ 37.589829] ? unwind_get_return_address+0x61/0xa0 [ 37.594725] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 37.599878] ? unwind_get_return_address+0x61/0xa0 [ 37.604772] ? __save_stack_trace+0x61/0xd0 [ 37.609059] ? get_signal+0x73f/0x16d0 [ 37.612910] ? save_stack_trace+0x16/0x20 [ 37.617021] ? __lock_acquire+0x20fd/0x4620 [ 37.621307] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 37.626463] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 37.631617] ? save_stack_trace+0x16/0x20 [ 37.635733] ? __lock_acquire+0x20fd/0x4620 [ 37.640021] ? osq_unlock+0x350/0x350 [ 37.643786] ? save_stack_trace+0x16/0x20 [ 37.647900] ? lock_release+0xd70/0xd70 [ 37.651841] ? check_noncircular+0x20/0x20 [ 37.656040] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 37.661193] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 37.666348] ? find_held_lock+0x39/0x1d0 [ 37.670375] ? lock_downgrade+0x990/0x990 [ 37.674486] ? check_noncircular+0x20/0x20 [ 37.678685] lock_acquire+0x1d5/0x580 [ 37.682451] ? exit_pi_state_list+0x369/0x7a0 [ 37.686912] ? lock_release+0xd70/0xd70 [ 37.690851] ? do_raw_spin_trylock+0x190/0x190 [ 37.695395] ? find_held_lock+0x39/0x1d0 [ 37.699427] _raw_spin_lock_irq+0x5e/0x80 [ 37.703536] ? exit_pi_state_list+0x369/0x7a0 [ 37.707995] exit_pi_state_list+0x369/0x7a0 [ 37.712282] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 37.718305] ? lock_release+0xd70/0xd70 [ 37.722245] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 37.728094] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 37.733162] ? __might_sleep+0x95/0x190 [ 37.737102] ? __might_fault+0x188/0x1d0 [ 37.741128] ? do_raw_spin_trylock+0x190/0x190 [ 37.745674] mm_release+0x46d/0x590 [ 37.749265] ? do_raw_spin_trylock+0x190/0x190 [ 37.753811] ? mm_access+0x140/0x140 [ 37.757489] ? _raw_spin_unlock_irq+0x27/0x70 [ 37.761948] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 37.766927] ? trace_hardirqs_on+0xd/0x10 [ 37.771039] ? _raw_spin_unlock_irq+0x27/0x70 [ 37.775497] ? acct_collect+0x637/0x800 [ 37.779435] do_exit+0x481/0x1b00 [ 37.782862] ? mm_update_next_owner+0x930/0x930 [ 37.787505] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 37.793371] ? find_held_lock+0x39/0x1d0 [ 37.797400] ? refill_pi_state_cache.part.6+0x2f0/0x2f0 [ 37.802727] ? check_noncircular+0x20/0x20 [ 37.806928] ? fault_in_user_writeable+0x90/0x90 [ 37.811649] ? futex_wake+0x680/0x680 [ 37.815413] ? find_held_lock+0x39/0x1d0 [ 37.819446] ? lock_downgrade+0x990/0x990 [ 37.823560] ? recalc_sigpending_tsk+0x117/0x150 [ 37.828279] ? recalc_sigpending+0x103/0x160 [ 37.832651] ? recalc_sigpending_tsk+0x150/0x150 [ 37.837368] ? get_signal+0x2b2/0x16d0 [ 37.841221] do_group_exit+0x149/0x400 [ 37.845074] ? __lock_is_held+0xbc/0x140 [ 37.849101] ? SyS_exit+0x30/0x30 [ 37.852521] ? _raw_spin_unlock_irq+0x27/0x70 [ 37.856981] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 37.861962] get_signal+0x73f/0x16d0 [ 37.865645] ? ptrace_notify+0x130/0x130 [ 37.869673] ? vma_wants_writenotify+0x3b0/0x3b0 [ 37.874398] ? exit_robust_list+0x240/0x240 [ 37.878687] ? lock_downgrade+0x990/0x990 [ 37.882812] ? SyS_brk+0x6f0/0x6f0 [ 37.886320] do_signal+0x94/0x1ee0 [ 37.889826] ? arch_get_unmapped_area+0x750/0x750 [ 37.894630] ? lock_acquire+0x1d5/0x580 [ 37.898577] ? find_held_lock+0x39/0x1d0 [ 37.902603] ? setup_sigcontext+0x7d0/0x7d0 [ 37.906898] ? lock_downgrade+0x990/0x990 [ 37.911022] ? down_write+0x120/0x120 [ 37.914785] ? lock_release+0xd70/0xd70 [ 37.918725] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 37.924575] ? vm_mmap_pgoff+0x1fc/0x280 [ 37.928616] ? exit_to_usermode_loop+0x8c/0x310 [ 37.933259] exit_to_usermode_loop+0x214/0x310 [ 37.937806] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 37.943309] ? kasan_check_write+0x14/0x20 [ 37.947510] syscall_return_slowpath+0x42f/0x510 [ 37.952230] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 37.957209] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 37.962102] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 37.967082] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 37.971803] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 37.976531] RIP: 0033:0x4520a9 [ 37.979686] RSP: 002b:00007f180e019cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 37.987363] RAX: fffffffffffffe00 RBX: 0000000000718028 RCX: 00000000004520a9 [ 37.994597] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000718028 [ 38.001833] RBP: 0000000000718000 R08: 0000000000000000 R09: 0000000000000000 [ 38.009067] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 38.016300] R13: 00007ffe724b563f R14: 00007f180e01a9c0 R15: 0000000000000000 [ 38.023537] [ 38.025129] Allocated by task 3585: [ 38.028720] save_stack_trace+0x16/0x20 [ 38.032657] save_stack+0x43/0xd0 [ 38.036072] kasan_kmalloc+0xad/0xe0 [ 38.039752] kmem_cache_alloc_trace+0x136/0x750 [ 38.044384] refill_pi_state_cache.part.6+0xa5/0x2f0 [ 38.049456] futex_requeue+0x1887/0x2370 [ 38.053480] do_futex+0x7f5/0x20d0 [ 38.056982] SyS_futex+0x260/0x390 [ 38.060489] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 38.065205] [ 38.066796] Freed by task 3568: [ 38.070038] save_stack_trace+0x16/0x20 [ 38.073981] save_stack+0x43/0xd0 [ 38.077396] kasan_slab_free+0x71/0xc0 [ 38.081245] kfree+0xca/0x250 [ 38.084312] put_pi_state+0x3f4/0x560 [ 38.088075] unqueue_me_pi+0x4a/0xc0 [ 38.091752] futex_wait_requeue_pi.constprop.19+0xc7f/0x1300 [ 38.097512] do_futex+0x825/0x20d0 [ 38.101015] SyS_futex+0x260/0x390 [ 38.104521] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 38.109236] [ 38.110829] The buggy address belongs to the object at ffff8801ccada800 [ 38.110829] which belongs to the cache kmalloc-256 of size 256 [ 38.123533] The buggy address is located 40 bytes inside of [ 38.123533] 256-byte region [ffff8801ccada800, ffff8801ccada900) [ 38.135279] The buggy address belongs to the page: [ 38.140170] page:ffffea000732b680 count:1 mapcount:0 mapping:ffff8801ccada080 index:0x0 [ 38.148275] flags: 0x200000000000100(slab) [ 38.152476] raw: 0200000000000100 ffff8801ccada080 0000000000000000 000000010000000c [ 38.160322] raw: ffffea000732dda0 ffffea0007301aa0 ffff8801dac007c0 0000000000000000 [ 38.168164] page dumped because: kasan: bad access detected [ 38.173833] [ 38.175422] Memory state around the buggy address: [ 38.180314] ffff8801ccada700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.187635] ffff8801ccada780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 38.194956] >ffff8801ccada800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.202282] ^ [ 38.206913] ffff8801ccada880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.214241] ffff8801ccada900: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 38.221561] ================================================================== [ 38.228882] Disabling lock debugging due to kernel taint [ 38.234294] Kernel panic - not syncing: panic_on_warn set ... [ 38.234294] [ 38.241622] CPU: 0 PID: 3556 Comm: syz-executor4 Tainted: G B 4.14.0-rc2-mm1+ #10 [ 38.250331] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.259650] Call Trace: [ 38.262206] dump_stack+0x194/0x257 [ 38.265801] ? arch_local_irq_restore+0x53/0x53 [ 38.270435] ? vprintk_default+0x28/0x30 [ 38.274463] ? __lock_acquire+0x4020/0x4620 [ 38.278750] panic+0x1e4/0x417 [ 38.281909] ? __warn+0x1d9/0x1d9 [ 38.285332] ? __lock_acquire+0x407b/0x4620 [ 38.289621] kasan_end_report+0x50/0x50 [ 38.293559] kasan_report+0x144/0x340 [ 38.297326] __asan_report_load8_noabort+0x14/0x20 [ 38.302221] __lock_acquire+0x407b/0x4620 [ 38.306334] ? unwind_dump+0x4c0/0x4c0 [ 38.310183] ? __unwind_start+0x169/0x330 [ 38.314297] ? __kernel_text_address+0xd/0x40 [ 38.318759] ? unwind_get_return_address+0x61/0xa0 [ 38.323654] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 38.328808] ? unwind_get_return_address+0x61/0xa0 [ 38.333700] ? __save_stack_trace+0x61/0xd0 [ 38.337986] ? get_signal+0x73f/0x16d0 [ 38.341836] ? save_stack_trace+0x16/0x20 [ 38.345950] ? __lock_acquire+0x20fd/0x4620 [ 38.350238] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 38.355404] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 38.360570] ? save_stack_trace+0x16/0x20 [ 38.364694] ? __lock_acquire+0x20fd/0x4620 [ 38.368981] ? osq_unlock+0x350/0x350 [ 38.372746] ? save_stack_trace+0x16/0x20 [ 38.376863] ? lock_release+0xd70/0xd70 [ 38.380804] ? check_noncircular+0x20/0x20 [ 38.385005] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 38.390161] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 38.395318] ? find_held_lock+0x39/0x1d0 [ 38.399344] ? lock_downgrade+0x990/0x990 [ 38.404163] ? check_noncircular+0x20/0x20 [ 38.408362] lock_acquire+0x1d5/0x580 [ 38.412128] ? exit_pi_state_list+0x369/0x7a0 [ 38.416588] ? lock_release+0xd70/0xd70 [ 38.420527] ? do_raw_spin_trylock+0x190/0x190 [ 38.425072] ? find_held_lock+0x39/0x1d0 [ 38.429102] _raw_spin_lock_irq+0x5e/0x80 [ 38.433214] ? exit_pi_state_list+0x369/0x7a0 [ 38.437672] exit_pi_state_list+0x369/0x7a0 [ 38.441960] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 38.447986] ? lock_release+0xd70/0xd70 [ 38.451926] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 38.457774] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 38.462842] ? __might_sleep+0x95/0x190 [ 38.466782] ? __might_fault+0x188/0x1d0 [ 38.470812] ? do_raw_spin_trylock+0x190/0x190 [ 38.475361] mm_release+0x46d/0x590 [ 38.478951] ? do_raw_spin_trylock+0x190/0x190 [ 38.483498] ? mm_access+0x140/0x140 [ 38.487178] ? _raw_spin_unlock_irq+0x27/0x70