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-kasan-gce-386-1,10.128.0.46' (ECDSA) to the list of known hosts. 2017/10/04 13:18:18 parsed 1 programs 2017/10/04 13:18:18 executed programs: 0 syzkaller login: [ 42.603363] ================================================================== [ 42.610782] BUG: KASAN: use-after-free in __lock_acquire+0x407b/0x4620 [ 42.617427] Read of size 8 at addr ffff8801c6c28b68 by task syz-executor4/3622 [ 42.624749] [ 42.626350] CPU: 0 PID: 3622 Comm: syz-executor4 Not tainted 4.14.0-rc3+ #24 [ 42.633507] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.633510] Call Trace: [ 42.633522] dump_stack+0x194/0x257 [ 42.633532] ? arch_local_irq_restore+0x53/0x53 [ 42.633538] ? show_regs_print_info+0x65/0x65 [ 42.633545] ? __kernel_text_address+0xd/0x40 [ 42.633554] ? __lock_acquire+0x407b/0x4620 [ 42.633562] print_address_description+0x73/0x250 [ 42.633568] ? __lock_acquire+0x407b/0x4620 [ 42.633573] kasan_report+0x25b/0x340 [ 42.633581] __asan_report_load8_noabort+0x14/0x20 [ 42.633587] __lock_acquire+0x407b/0x4620 [ 42.633594] ? unwind_dump+0x4c0/0x4c0 [ 42.633600] ? __kernel_text_address+0xd/0x40 [ 42.633606] ? unwind_get_return_address+0x61/0xa0 [ 42.633617] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 42.633624] ? __save_stack_trace+0x61/0xd0 [ 42.633632] ? get_signal+0x73f/0x16d0 [ 42.633639] ? save_stack_trace+0x16/0x20 [ 42.633645] ? __lock_acquire+0x20fd/0x4620 [ 42.633654] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 42.633665] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 42.633672] ? save_stack_trace+0x16/0x20 [ 42.633678] ? __lock_acquire+0x20fd/0x4620 [ 42.633684] ? osq_unlock+0x350/0x350 [ 42.633688] ? save_stack_trace+0x16/0x20 [ 42.633698] ? check_noncircular+0x20/0x20 [ 42.633706] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 42.633714] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 42.633722] ? __unwind_start+0x169/0x330 [ 42.633730] ? find_held_lock+0x39/0x1d0 [ 42.633741] ? lock_downgrade+0x990/0x990 [ 42.633746] ? check_noncircular+0x20/0x20 [ 42.633758] lock_acquire+0x1d5/0x580 [ 42.633764] ? exit_pi_state_list+0x369/0x7a0 [ 42.633773] ? lock_release+0xd70/0xd70 [ 42.633778] ? do_raw_spin_trylock+0x190/0x190 [ 42.633783] ? find_held_lock+0x39/0x1d0 [ 42.633797] _raw_spin_lock_irq+0x5e/0x80 [ 42.633801] ? exit_pi_state_list+0x369/0x7a0 [ 42.633807] exit_pi_state_list+0x369/0x7a0 [ 42.633818] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 42.633824] ? lock_release+0xd70/0xd70 [ 42.633831] ? check_same_owner+0x320/0x320 [ 42.633838] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 42.633846] ? __might_sleep+0x95/0x190 [ 42.633855] ? __might_fault+0x188/0x1d0 [ 42.633864] ? do_raw_spin_trylock+0x190/0x190 [ 42.633872] mm_release+0x46d/0x590 [ 42.633877] ? do_raw_spin_trylock+0x190/0x190 [ 42.633882] ? mm_access+0x140/0x140 [ 42.633888] ? _raw_spin_unlock_irq+0x27/0x70 [ 42.633895] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 42.633902] ? trace_hardirqs_on+0xd/0x10 [ 42.633907] ? _raw_spin_unlock_irq+0x27/0x70 [ 42.633913] ? acct_collect+0x637/0x800 [ 42.633919] do_exit+0x481/0x1af0 [ 42.633928] ? mm_update_next_owner+0x930/0x930 [ 42.633934] ? lock_downgrade+0x990/0x990 [ 42.633939] ? refill_pi_state_cache.part.6+0x2f0/0x2f0 [ 42.633947] ? futex_wait+0x3ad/0x990 [ 42.633955] ? do_raw_spin_trylock+0x190/0x190 [ 42.633961] ? fault_in_user_writeable+0x90/0x90 [ 42.633968] ? futex_wake+0x680/0x680 [ 42.633973] ? fault_in_user_writeable+0x90/0x90 [ 42.633980] ? check_noncircular+0x20/0x20 [ 42.633986] ? drop_futex_key_refs.isra.13+0x63/0xb0 [ 42.633992] ? futex_wait+0x69e/0x990 [ 42.634001] ? futex_wait_setup+0x3d0/0x3d0 [ 42.634009] ? find_held_lock+0x39/0x1d0 [ 42.634020] ? lock_downgrade+0x990/0x990 [ 42.634027] ? recalc_sigpending_tsk+0x117/0x150 [ 42.634034] ? recalc_sigpending+0x103/0x160 [ 42.634040] ? recalc_sigpending_tsk+0x150/0x150 [ 42.634045] ? get_signal+0x2b2/0x16d0 [ 42.634055] do_group_exit+0x149/0x400 [ 42.634061] ? __lock_is_held+0xbc/0x140 [ 42.634066] ? SyS_exit+0x30/0x30 [ 42.634071] ? _raw_spin_unlock_irq+0x27/0x70 [ 42.634079] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 42.634086] get_signal+0x73f/0x16d0 [ 42.634095] ? ptrace_notify+0x130/0x130 [ 42.634100] ? __lock_is_held+0xbc/0x140 [ 42.634119] do_signal+0x94/0x1ee0 [ 42.634127] ? __might_sleep+0x95/0x190 [ 42.634135] ? setup_sigcontext+0x7d0/0x7d0 [ 42.634143] ? snd_timer_user_ioctl_compat+0x46c/0x821 [ 42.634149] ? snd_timer_user_ioctl+0x32e0/0x32e0 [ 42.634156] ? selinux_capable+0x40/0x40 [ 42.634164] ? putname+0xee/0x130 [ 42.634170] ? putname+0xee/0x130 [ 42.634176] ? rcu_read_lock_sched_held+0x108/0x120 [ 42.634181] ? __compat_get_timespec+0xd9/0x120 [ 42.634191] ? exit_to_usermode_loop+0x8c/0x310 [ 42.634200] exit_to_usermode_loop+0x214/0x310 [ 42.634207] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 42.634214] ? do_fast_syscall_32+0x158/0xf05 [ 42.634223] do_fast_syscall_32+0x83e/0xf05 [ 42.634231] ? do_int80_syscall_32+0x940/0x940 [ 42.634239] ? lockdep_sys_exit+0x47/0xf0 [ 42.634246] ? syscall_return_slowpath+0x2b3/0x510 [ 42.634251] ? finish_task_switch+0x1aa/0x740 [ 42.634258] ? sysret32_from_system_call+0x5/0x3b [ 42.634266] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.634275] entry_SYSENTER_compat+0x51/0x60 [ 42.634279] RIP: 0023:0xf7fc5c79 [ 42.634282] RSP: 002b:00000000f7f5e12c EFLAGS: 00000292 ORIG_RAX: 00000000000000f0 [ 42.634288] RAX: fffffffffffffe00 RBX: 0000000008128168 RCX: 0000000000000000 [ 42.634292] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 42.634295] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 42.634298] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 42.634301] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 42.634310] [ 42.634313] Allocated by task 3648: [ 42.634319] save_stack_trace+0x16/0x20 [ 42.634324] save_stack+0x43/0xd0 [ 42.634329] kasan_kmalloc+0xad/0xe0 [ 42.634335] kmem_cache_alloc_trace+0x136/0x750 [ 42.634340] refill_pi_state_cache.part.6+0xa5/0x2f0 [ 42.634344] futex_requeue+0x1887/0x2370 [ 42.634348] do_futex+0x7f5/0x20d0 [ 42.634353] compat_SyS_futex+0x27f/0x380 [ 42.634357] do_fast_syscall_32+0x3f2/0xf05 [ 42.634362] entry_SYSENTER_compat+0x51/0x60 [ 42.634363] [ 42.634365] Freed by task 3615: [ 42.634370] save_stack_trace+0x16/0x20 [ 42.634375] save_stack+0x43/0xd0 [ 42.634379] kasan_slab_free+0x71/0xc0 [ 42.634383] kfree+0xca/0x250 [ 42.634387] put_pi_state+0x3f4/0x560 [ 42.634391] unqueue_me_pi+0x4a/0xc0 [ 42.634397] futex_wait_requeue_pi.constprop.19+0xc7f/0x1300 [ 42.634400] do_futex+0x825/0x20d0 [ 42.634405] compat_SyS_futex+0x27f/0x380 [ 42.634410] do_fast_syscall_32+0x3f2/0xf05 [ 42.634414] entry_SYSENTER_compat+0x51/0x60 [ 42.634415] [ 42.634419] The buggy address belongs to the object at ffff8801c6c28b40 [ 42.634419] which belongs to the cache kmalloc-256 of size 256 [ 42.634424] The buggy address is located 40 bytes inside of [ 42.634424] 256-byte region [ffff8801c6c28b40, ffff8801c6c28c40) [ 42.634425] The buggy address belongs to the page: [ 42.634430] page:ffffea00071b0a00 count:1 mapcount:0 mapping:ffff8801c6c28000 index:0x0 [ 42.634435] flags: 0x200000000000100(slab) [ 42.634443] raw: 0200000000000100 ffff8801c6c28000 0000000000000000 000000010000000c [ 42.634450] raw: ffffea00071b4c60 ffffea00071a1060 ffff8801dac007c0 0000000000000000 [ 42.634452] page dumped because: kasan: bad access detected [ 42.634453] [ 42.634454] Memory state around the buggy address: [ 42.634459] ffff8801c6c28a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.634464] ffff8801c6c28a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.634468] >ffff8801c6c28b00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 42.634470] ^ [ 42.634474] ffff8801c6c28b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.634478] ffff8801c6c28c00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 42.634480] ================================================================== [ 42.634482] Disabling lock debugging due to kernel taint [ 42.634485] Kernel panic - not syncing: panic_on_warn set ... [ 42.634485] [ 42.634491] CPU: 0 PID: 3622 Comm: syz-executor4 Tainted: G B 4.14.0-rc3+ #24 [ 42.634494] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.634496] Call Trace: [ 42.634503] dump_stack+0x194/0x257 [ 42.634510] ? arch_local_irq_restore+0x53/0x53 [ 42.634515] ? vprintk_default+0x28/0x30 [ 42.634523] ? __lock_acquire+0x3ff0/0x4620 [ 42.634529] panic+0x1e4/0x417 [ 42.634534] ? __warn+0x1d9/0x1d9 [ 42.634546] ? __lock_acquire+0x407b/0x4620 [ 42.634551] kasan_end_report+0x50/0x50 [ 42.634556] kasan_report+0x144/0x340 [ 42.634563] __asan_report_load8_noabort+0x14/0x20 [ 42.634569] __lock_acquire+0x407b/0x4620 [ 42.634574] ? unwind_dump+0x4c0/0x4c0 [ 42.634581] ? __kernel_text_address+0xd/0x40 [ 42.634586] ? unwind_get_return_address+0x61/0xa0 [ 42.634597] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 42.634603] ? __save_stack_trace+0x61/0xd0 [ 42.634610] ? get_signal+0x73f/0x16d0 [ 42.634617] ? save_stack_trace+0x16/0x20 [ 42.634622] ? __lock_acquire+0x20fd/0x4620 [ 42.634632] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 42.634642] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 42.634649] ? save_stack_trace+0x16/0x20 [ 42.634655] ? __lock_acquire+0x20fd/0x4620 [ 42.634660] ? osq_unlock+0x350/0x350 [ 42.634665] ? save_stack_trace+0x16/0x20 [ 42.634674] ? check_noncircular+0x20/0x20 [ 42.634682] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 42.634690] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 42.634697] ? __unwind_start+0x169/0x330 [ 42.634705] ? find_held_lock+0x39/0x1d0 [ 42.634716] ? lock_downgrade+0x990/0x990 [ 42.634721] ? check_noncircular+0x20/0x20 [ 42.634729] lock_acquire+0x1d5/0x580 [ 42.634734] ? exit_pi_state_list+0x369/0x7a0 [ 42.634743] ? lock_release+0xd70/0xd70 [ 42.634748] ? do_raw_spin_trylock+0x190/0x190 [ 42.634757] ? find_held_lock+0x39/0x1d0 [ 42.634769] _raw_spin_lock_irq+0x5e/0x80 [ 42.634774] ? exit_pi_state_list+0x369/0x7a0 [ 42.634779] exit_pi_state_list+0x369/0x7a0 [ 42.634790] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 42.634797] ? lock_release+0xd70/0xd70 [ 42.634802] ? check_same_owner+0x320/0x320 [ 42.634809] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 42.634817] ? __might_sleep+0x95/0x190 [ 42.634825] ? __might_fault+0x188/0x1d0 [ 42.634833] ? do_raw_spin_trylock+0x190/0x190 [ 42.634840] mm_release+0x46d/0x590 [ 42.634844] ? do_raw_spin_trylock+0x190/0x190 [ 42.634850] ? mm_access+0x140/0x140 [ 42.634856] ? _raw_spin_unlock_irq+0x27/0x70