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-386-2,10.128.0.24' (ECDSA) to the list of known hosts. 2017/10/04 06:35:48 parsed 1 programs 2017/10/04 06:35:48 executed programs: 0 syzkaller login: [ 43.631959] ================================================================== [ 43.639371] BUG: KASAN: use-after-free in __lock_acquire+0x407b/0x4620 [ 43.646012] Read of size 8 at addr ffff8801cc4b8168 by task syz-executor1/4353 [ 43.653348] [ 43.654954] CPU: 1 PID: 4353 Comm: syz-executor1 Not tainted 4.14.0-rc3+ #24 [ 43.662111] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.671430] Call Trace: [ 43.673988] dump_stack+0x194/0x257 [ 43.677595] ? arch_local_irq_restore+0x53/0x53 [ 43.682242] ? show_regs_print_info+0x65/0x65 [ 43.686703] ? __kernel_text_address+0xd/0x40 [ 43.691164] ? __lock_acquire+0x407b/0x4620 [ 43.695451] print_address_description+0x73/0x250 [ 43.700257] ? __lock_acquire+0x407b/0x4620 [ 43.704544] kasan_report+0x25b/0x340 [ 43.708311] __asan_report_load8_noabort+0x14/0x20 [ 43.713204] __lock_acquire+0x407b/0x4620 [ 43.717318] ? unwind_dump+0x4c0/0x4c0 [ 43.721173] ? __kernel_text_address+0xd/0x40 [ 43.725637] ? unwind_get_return_address+0x61/0xa0 [ 43.730537] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 43.735694] ? __save_stack_trace+0x61/0xd0 [ 43.739982] ? get_signal+0x73f/0x16d0 [ 43.743835] ? save_stack_trace+0x16/0x20 [ 43.747948] ? __lock_acquire+0x20fd/0x4620 [ 43.752237] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 43.757396] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 43.762554] ? save_stack_trace+0x16/0x20 [ 43.766666] ? __lock_acquire+0x20fd/0x4620 [ 43.770953] ? osq_unlock+0x350/0x350 [ 43.774717] ? save_stack_trace+0x16/0x20 [ 43.778833] ? check_noncircular+0x20/0x20 [ 43.783035] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 43.788191] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 43.793349] ? __unwind_start+0x169/0x330 [ 43.797475] ? find_held_lock+0x39/0x1d0 [ 43.801503] ? lock_downgrade+0x990/0x990 [ 43.805614] ? check_noncircular+0x20/0x20 [ 43.809815] lock_acquire+0x1d5/0x580 [ 43.813580] ? exit_pi_state_list+0x369/0x7a0 [ 43.818042] ? lock_release+0xd70/0xd70 [ 43.821979] ? do_raw_spin_trylock+0x190/0x190 [ 43.826525] ? find_held_lock+0x39/0x1d0 [ 43.830558] _raw_spin_lock_irq+0x5e/0x80 [ 43.834675] ? exit_pi_state_list+0x369/0x7a0 [ 43.839140] exit_pi_state_list+0x369/0x7a0 [ 43.843429] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 43.849455] ? lock_release+0xd70/0xd70 [ 43.853400] ? check_same_owner+0x320/0x320 [ 43.857689] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 43.862758] ? __might_sleep+0x95/0x190 [ 43.866699] ? __might_fault+0x188/0x1d0 [ 43.870730] ? do_raw_spin_trylock+0x190/0x190 [ 43.875280] mm_release+0x46d/0x590 [ 43.878875] ? do_raw_spin_trylock+0x190/0x190 [ 43.883421] ? mm_access+0x140/0x140 [ 43.887104] ? _raw_spin_unlock_irq+0x27/0x70 [ 43.891564] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 43.896547] ? trace_hardirqs_on+0xd/0x10 [ 43.900660] ? _raw_spin_unlock_irq+0x27/0x70 [ 43.905121] ? acct_collect+0x637/0x800 [ 43.909064] do_exit+0x481/0x1af0 [ 43.912498] ? mm_update_next_owner+0x930/0x930 [ 43.917135] ? lock_downgrade+0x990/0x990 [ 43.921252] ? refill_pi_state_cache.part.6+0x2f0/0x2f0 [ 43.926581] ? futex_wait+0x3ad/0x990 [ 43.930349] ? do_raw_spin_trylock+0x190/0x190 [ 43.934897] ? fault_in_user_writeable+0x90/0x90 [ 43.939621] ? futex_wake+0x680/0x680 [ 43.943390] ? fault_in_user_writeable+0x90/0x90 [ 43.948117] ? check_noncircular+0x20/0x20 [ 43.952323] ? drop_futex_key_refs.isra.13+0x63/0xb0 [ 43.957392] ? futex_wait+0x69e/0x990 [ 43.961160] ? futex_wait_setup+0x3d0/0x3d0 [ 43.965451] ? find_held_lock+0x39/0x1d0 [ 43.969482] ? lock_downgrade+0x990/0x990 [ 43.973606] ? recalc_sigpending_tsk+0x117/0x150 [ 43.978327] ? recalc_sigpending+0x103/0x160 [ 43.982698] ? recalc_sigpending_tsk+0x150/0x150 [ 43.987421] ? get_signal+0x2b2/0x16d0 [ 43.991275] do_group_exit+0x149/0x400 [ 43.995127] ? __lock_is_held+0xbc/0x140 [ 43.999153] ? SyS_exit+0x30/0x30 [ 44.002572] ? _raw_spin_unlock_irq+0x27/0x70 [ 44.007043] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 44.012030] get_signal+0x73f/0x16d0 [ 44.015712] ? ptrace_notify+0x130/0x130 [ 44.019744] ? lock_downgrade+0x990/0x990 [ 44.023863] ? SyS_brk+0x6f0/0x6f0 [ 44.027370] ? arch_get_unmapped_area+0x750/0x750 [ 44.032177] ? lock_acquire+0x1d5/0x580 [ 44.036118] ? vm_mmap_pgoff+0x198/0x280 [ 44.040146] ? userfaultfd_unmap_complete+0x327/0x510 [ 44.045305] do_signal+0x94/0x1ee0 [ 44.048811] ? do_mmap+0x34f/0xd50 [ 44.052316] ? up_write+0x6b/0x120 [ 44.055822] ? setup_sigcontext+0x7d0/0x7d0 [ 44.060111] ? security_mmap_file+0x143/0x180 [ 44.064576] ? vm_mmap_pgoff+0x1fc/0x280 [ 44.068604] ? vm_mmap_pgoff+0x13b/0x280 [ 44.072632] ? vma_is_stack_for_current+0xa0/0xa0 [ 44.077441] ? find_held_lock+0x39/0x1d0 [ 44.081469] ? __compat_get_timespec+0xd9/0x120 [ 44.086107] ? exit_to_usermode_loop+0x8c/0x310 [ 44.090742] exit_to_usermode_loop+0x214/0x310 [ 44.095292] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 44.100795] ? lock_acquire+0x1d5/0x580 [ 44.104738] ? do_fast_syscall_32+0x158/0xf05 [ 44.109201] do_fast_syscall_32+0x83e/0xf05 [ 44.113491] ? compat_start_thread+0x80/0x80 [ 44.117868] ? do_int80_syscall_32+0x940/0x940 [ 44.122415] ? lockdep_sys_exit+0x47/0xf0 [ 44.126539] ? syscall_return_slowpath+0x2b3/0x510 [ 44.131469] ? finish_task_switch+0x1aa/0x740 [ 44.135934] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 44.140917] ? sysret32_from_system_call+0x5/0x3b [ 44.145724] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 44.150540] entry_SYSENTER_compat+0x51/0x60 [ 44.154923] RIP: 0023:0xf7f7fc79 [ 44.158255] RSP: 002b:00000000f7f7b12c EFLAGS: 00000292 ORIG_RAX: 00000000000000f0 [ 44.165927] RAX: fffffffffffffe00 RBX: 0000000008128018 RCX: 0000000000000000 [ 44.173162] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 44.180398] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 44.187633] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 44.194870] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 44.202110] [ 44.203703] Allocated by task 4381: [ 44.207301] save_stack_trace+0x16/0x20 [ 44.211241] save_stack+0x43/0xd0 [ 44.214659] kasan_kmalloc+0xad/0xe0 [ 44.218339] kmem_cache_alloc_trace+0x136/0x750 [ 44.222971] refill_pi_state_cache.part.6+0xa5/0x2f0 [ 44.228682] futex_requeue+0x1887/0x2370 [ 44.232707] do_futex+0x7f5/0x20d0 [ 44.236213] compat_SyS_futex+0x27f/0x380 [ 44.240330] do_fast_syscall_32+0x3f2/0xf05 [ 44.244620] entry_SYSENTER_compat+0x51/0x60 [ 44.248989] [ 44.250584] Freed by task 4367: [ 44.253830] save_stack_trace+0x16/0x20 [ 44.257770] save_stack+0x43/0xd0 [ 44.261191] kasan_slab_free+0x71/0xc0 [ 44.265050] kfree+0xca/0x250 [ 44.268120] put_pi_state+0x3f4/0x560 [ 44.271884] unqueue_me_pi+0x4a/0xc0 [ 44.275562] futex_wait_requeue_pi.constprop.19+0xc7f/0x1300 [ 44.281324] do_futex+0x825/0x20d0 [ 44.284829] compat_SyS_futex+0x27f/0x380 [ 44.288944] do_fast_syscall_32+0x3f2/0xf05 [ 44.293229] entry_SYSENTER_compat+0x51/0x60 [ 44.297600] [ 44.299196] The buggy address belongs to the object at ffff8801cc4b8140 [ 44.299196] which belongs to the cache kmalloc-256 of size 256 [ 44.311817] The buggy address is located 40 bytes inside of [ 44.311817] 256-byte region [ffff8801cc4b8140, ffff8801cc4b8240) [ 44.323569] The buggy address belongs to the page: [ 44.328465] page:ffffea0007312e00 count:1 mapcount:0 mapping:ffff8801cc4b8000 index:0x0 [ 44.336571] flags: 0x200000000000100(slab) [ 44.340772] raw: 0200000000000100 ffff8801cc4b8000 0000000000000000 000000010000000c [ 44.348618] raw: ffffea00072e8ae0 ffffea00072e32e0 ffff8801dac007c0 0000000000000000 [ 44.356461] page dumped because: kasan: bad access detected [ 44.362136] [ 44.363729] Memory state around the buggy address: [ 44.368633] ffff8801cc4b8000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 44.375958] ffff8801cc4b8080: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 44.383283] >ffff8801cc4b8100: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 44.390604] ^ [ 44.397325] ffff8801cc4b8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.404652] ffff8801cc4b8200: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 44.411974] ================================================================== [ 44.419299] Disabling lock debugging due to kernel taint [ 44.424720] Kernel panic - not syncing: panic_on_warn set ... [ 44.424720] [ 44.432049] CPU: 1 PID: 4353 Comm: syz-executor1 Tainted: G B 4.14.0-rc3+ #24 [ 44.440412] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.449733] Call Trace: [ 44.452290] dump_stack+0x194/0x257 [ 44.455883] ? arch_local_irq_restore+0x53/0x53 [ 44.460518] ? vprintk_default+0x28/0x30 [ 44.464547] ? __lock_acquire+0x3ff0/0x4620 [ 44.468836] panic+0x1e4/0x417 [ 44.471993] ? __warn+0x1d9/0x1d9 [ 44.475418] ? __lock_acquire+0x407b/0x4620 [ 44.479704] kasan_end_report+0x50/0x50 [ 44.483642] kasan_report+0x144/0x340 [ 44.487409] __asan_report_load8_noabort+0x14/0x20 [ 44.492303] __lock_acquire+0x407b/0x4620 [ 44.496415] ? unwind_dump+0x4c0/0x4c0 [ 44.500272] ? __kernel_text_address+0xd/0x40 [ 44.504732] ? unwind_get_return_address+0x61/0xa0 [ 44.509631] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 44.514784] ? __save_stack_trace+0x61/0xd0 [ 44.519072] ? get_signal+0x73f/0x16d0 [ 44.522926] ? save_stack_trace+0x16/0x20 [ 44.527039] ? __lock_acquire+0x20fd/0x4620 [ 44.531329] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 44.536486] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 44.541639] ? save_stack_trace+0x16/0x20 [ 44.545752] ? __lock_acquire+0x20fd/0x4620 [ 44.550038] ? osq_unlock+0x350/0x350 [ 44.553804] ? save_stack_trace+0x16/0x20 [ 44.557920] ? check_noncircular+0x20/0x20 [ 44.562121] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 44.567277] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 44.572433] ? __unwind_start+0x169/0x330 [ 44.576551] ? find_held_lock+0x39/0x1d0 [ 44.580595] ? lock_downgrade+0x990/0x990 [ 44.584719] ? check_noncircular+0x20/0x20 [ 44.588922] lock_acquire+0x1d5/0x580 [ 44.592691] ? exit_pi_state_list+0x369/0x7a0 [ 44.597156] ? lock_release+0xd70/0xd70 [ 44.601096] ? do_raw_spin_trylock+0x190/0x190 [ 44.605643] ? find_held_lock+0x39/0x1d0 [ 44.609675] _raw_spin_lock_irq+0x5e/0x80 [ 44.613789] ? exit_pi_state_list+0x369/0x7a0 [ 44.618253] exit_pi_state_list+0x369/0x7a0 [ 44.622557] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 44.628584] ? lock_release+0xd70/0xd70