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-9,10.128.0.20' (ECDSA) to the list of known hosts. 2017/09/29 19:15:49 parsed 1 programs 2017/09/29 19:15:49 executed programs: 0 syzkaller login: [ 35.681859] ================================================================== [ 35.689266] BUG: KASAN: use-after-free in __lock_acquire+0x407b/0x4620 [ 35.695914] Read of size 8 at addr ffff8801ca5a40e8 by task syz-executor4/5087 [ 35.703243] [ 35.704844] CPU: 0 PID: 5087 Comm: syz-executor4 Not tainted 4.14.0-rc2-mm1+ #10 [ 35.712349] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.721679] Call Trace: [ 35.724235] dump_stack+0x194/0x257 [ 35.727844] ? arch_local_irq_restore+0x53/0x53 [ 35.732493] ? show_regs_print_info+0x65/0x65 [ 35.736966] ? __kernel_text_address+0xd/0x40 [ 35.741443] ? __lock_acquire+0x407b/0x4620 [ 35.745738] print_address_description+0x73/0x250 [ 35.750548] ? __lock_acquire+0x407b/0x4620 [ 35.754840] kasan_report+0x25b/0x340 [ 35.758606] __asan_report_load8_noabort+0x14/0x20 [ 35.763511] __lock_acquire+0x407b/0x4620 [ 35.767640] ? unwind_dump+0x4c0/0x4c0 [ 35.771501] ? __unwind_start+0x169/0x330 [ 35.775623] ? __kernel_text_address+0xd/0x40 [ 35.780095] ? unwind_get_return_address+0x61/0xa0 [ 35.785019] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.790205] ? unwind_get_return_address+0x61/0xa0 [ 35.795118] ? __save_stack_trace+0x61/0xd0 [ 35.799430] ? get_signal+0x73f/0x16d0 [ 35.803312] ? save_stack_trace+0x16/0x20 [ 35.807456] ? __lock_acquire+0x20fd/0x4620 [ 35.811759] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.816932] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.822106] ? save_stack_trace+0x16/0x20 [ 35.826238] ? __lock_acquire+0x20fd/0x4620 [ 35.830552] ? osq_unlock+0x350/0x350 [ 35.834340] ? save_stack_trace+0x16/0x20 [ 35.838464] ? lock_release+0xd70/0xd70 [ 35.842420] ? check_noncircular+0x20/0x20 [ 35.846727] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.851916] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.857102] ? find_held_lock+0x39/0x1d0 [ 35.861167] ? lock_downgrade+0x990/0x990 [ 35.865306] ? check_noncircular+0x20/0x20 [ 35.869525] lock_acquire+0x1d5/0x580 [ 35.873301] ? exit_pi_state_list+0x369/0x7a0 [ 35.877779] ? lock_release+0xd70/0xd70 [ 35.881738] ? do_raw_spin_trylock+0x190/0x190 [ 35.886301] ? find_held_lock+0x39/0x1d0 [ 35.890364] _raw_spin_lock_irq+0x5e/0x80 [ 35.894486] ? exit_pi_state_list+0x369/0x7a0 [ 35.898949] exit_pi_state_list+0x369/0x7a0 [ 35.903263] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 35.909311] ? lock_release+0xd70/0xd70 [ 35.913272] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 35.919136] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 35.924210] ? __might_sleep+0x95/0x190 [ 35.928158] ? __might_fault+0x188/0x1d0 [ 35.932195] ? do_raw_spin_trylock+0x190/0x190 [ 35.936755] mm_release+0x46d/0x590 [ 35.940357] ? do_raw_spin_trylock+0x190/0x190 [ 35.944914] ? mm_access+0x140/0x140 [ 35.948595] ? _raw_spin_unlock_irq+0x27/0x70 [ 35.953062] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 35.958059] ? trace_hardirqs_on+0xd/0x10 [ 35.962185] ? _raw_spin_unlock_irq+0x27/0x70 [ 35.966656] ? acct_collect+0x637/0x800 [ 35.970617] do_exit+0x481/0x1b00 [ 35.974042] ? mm_update_next_owner+0x930/0x930 [ 35.978680] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 35.984531] ? find_held_lock+0x39/0x1d0 [ 35.988573] ? refill_pi_state_cache.part.6+0x2f0/0x2f0 [ 35.993912] ? check_noncircular+0x20/0x20 [ 35.998117] ? fault_in_user_writeable+0x90/0x90 [ 36.002841] ? futex_wake+0x680/0x680 [ 36.006612] ? find_held_lock+0x39/0x1d0 [ 36.010654] ? lock_downgrade+0x990/0x990 [ 36.014783] ? recalc_sigpending_tsk+0x117/0x150 [ 36.019506] ? recalc_sigpending+0x103/0x160 [ 36.023882] ? recalc_sigpending_tsk+0x150/0x150 [ 36.028603] ? get_signal+0x2b2/0x16d0 [ 36.032458] do_group_exit+0x149/0x400 [ 36.036313] ? __lock_is_held+0xbc/0x140 [ 36.040337] ? SyS_exit+0x30/0x30 [ 36.043757] ? _raw_spin_unlock_irq+0x27/0x70 [ 36.048243] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 36.053241] get_signal+0x73f/0x16d0 [ 36.056922] ? ptrace_notify+0x130/0x130 [ 36.060957] ? __schedule+0x8f0/0x2070 [ 36.064831] ? exit_robust_list+0x240/0x240 [ 36.069120] ? lock_downgrade+0x990/0x990 [ 36.073239] ? SyS_brk+0x6f0/0x6f0 [ 36.076749] do_signal+0x94/0x1ee0 [ 36.080257] ? arch_get_unmapped_area+0x750/0x750 [ 36.085070] ? lock_acquire+0x1d5/0x580 [ 36.089024] ? find_held_lock+0x39/0x1d0 [ 36.093058] ? setup_sigcontext+0x7d0/0x7d0 [ 36.097357] ? lock_downgrade+0x990/0x990 [ 36.101496] ? down_write+0x120/0x120 [ 36.105276] ? lock_release+0xd70/0xd70 [ 36.109222] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 36.115074] ? vm_mmap_pgoff+0x1fc/0x280 [ 36.119188] ? exit_to_usermode_loop+0x8c/0x310 [ 36.123824] exit_to_usermode_loop+0x214/0x310 [ 36.128372] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 36.133877] ? kasan_check_write+0x14/0x20 [ 36.138078] syscall_return_slowpath+0x42f/0x510 [ 36.142798] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 36.147780] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 36.152677] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 36.157659] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 36.162384] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 36.167102] RIP: 0033:0x4520a9 [ 36.170258] RSP: 002b:00007f20a6c27cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 36.177936] RAX: fffffffffffffe00 RBX: 0000000000718028 RCX: 00000000004520a9 [ 36.185180] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000718028 [ 36.192417] RBP: 0000000000718000 R08: 0000000000000000 R09: 0000000000000000 [ 36.199657] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 36.206903] R13: 00007ffeaf9d360f R14: 00007f20a6c289c0 R15: 0000000000000000 [ 36.214147] [ 36.215744] Allocated by task 5112: [ 36.219345] save_stack_trace+0x16/0x20 [ 36.223284] save_stack+0x43/0xd0 [ 36.226702] kasan_kmalloc+0xad/0xe0 [ 36.230380] kmem_cache_alloc_trace+0x136/0x750 [ 36.235019] refill_pi_state_cache.part.6+0xa5/0x2f0 [ 36.240100] futex_requeue+0x1887/0x2370 [ 36.244126] do_futex+0x7f5/0x20d0 [ 36.247629] SyS_futex+0x260/0x390 [ 36.251141] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 36.255858] [ 36.257454] Freed by task 5097: [ 36.260706] save_stack_trace+0x16/0x20 [ 36.264645] save_stack+0x43/0xd0 [ 36.268064] kasan_slab_free+0x71/0xc0 [ 36.271914] kfree+0xca/0x250 [ 36.274983] put_pi_state+0x3f4/0x560 [ 36.278747] unqueue_me_pi+0x4a/0xc0 [ 36.282428] futex_wait_requeue_pi.constprop.19+0xc7f/0x1300 [ 36.288188] do_futex+0x825/0x20d0 [ 36.291693] SyS_futex+0x260/0x390 [ 36.295199] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 36.299922] [ 36.301530] The buggy address belongs to the object at ffff8801ca5a40c0 [ 36.301530] which belongs to the cache kmalloc-256 of size 256 [ 36.314155] The buggy address is located 40 bytes inside of [ 36.314155] 256-byte region [ffff8801ca5a40c0, ffff8801ca5a41c0) [ 36.325905] The buggy address belongs to the page: [ 36.330799] page:ffffea0007296900 count:1 mapcount:0 mapping:ffff8801ca5a40c0 index:0x0 [ 36.338904] flags: 0x200000000000100(slab) [ 36.343105] raw: 0200000000000100 ffff8801ca5a40c0 0000000000000000 000000010000000c [ 36.350948] raw: ffffea00072a1da0 ffffea00072818a0 ffff8801dac007c0 0000000000000000 [ 36.358796] page dumped because: kasan: bad access detected [ 36.364468] [ 36.366060] Memory state around the buggy address: [ 36.370952] ffff8801ca5a3f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 36.378282] ffff8801ca5a4000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 36.385605] >ffff8801ca5a4080: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 36.392927] ^ [ 36.399652] ffff8801ca5a4100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 36.406975] ffff8801ca5a4180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 36.414295] ================================================================== [ 36.421623] Disabling lock debugging due to kernel taint [ 36.427037] Kernel panic - not syncing: panic_on_warn set ... [ 36.427037] [ 36.434364] CPU: 0 PID: 5087 Comm: syz-executor4 Tainted: G B 4.14.0-rc2-mm1+ #10 [ 36.443085] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 36.452418] Call Trace: [ 36.454976] dump_stack+0x194/0x257 [ 36.458573] ? arch_local_irq_restore+0x53/0x53 [ 36.463207] ? vprintk_default+0x28/0x30 [ 36.467235] ? __lock_acquire+0x4020/0x4620 [ 36.471521] panic+0x1e4/0x417 [ 36.474679] ? __warn+0x1d9/0x1d9 [ 36.478102] ? __lock_acquire+0x407b/0x4620 [ 36.482389] kasan_end_report+0x50/0x50 [ 36.486328] kasan_report+0x144/0x340 [ 36.490094] __asan_report_load8_noabort+0x14/0x20 [ 36.494987] __lock_acquire+0x407b/0x4620 [ 36.499107] ? unwind_dump+0x4c0/0x4c0 [ 36.502955] ? __unwind_start+0x169/0x330 [ 36.507066] ? __kernel_text_address+0xd/0x40 [ 36.511524] ? unwind_get_return_address+0x61/0xa0 [ 36.516422] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 36.521573] ? unwind_get_return_address+0x61/0xa0 [ 36.526466] ? __save_stack_trace+0x61/0xd0 [ 36.530754] ? get_signal+0x73f/0x16d0 [ 36.534607] ? save_stack_trace+0x16/0x20 [ 36.538721] ? __lock_acquire+0x20fd/0x4620 [ 36.543011] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 36.548172] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 36.553362] ? save_stack_trace+0x16/0x20 [ 36.557489] ? __lock_acquire+0x20fd/0x4620 [ 36.561780] ? osq_unlock+0x350/0x350 [ 36.565551] ? save_stack_trace+0x16/0x20 [ 36.569663] ? lock_release+0xd70/0xd70 [ 36.573605] ? check_noncircular+0x20/0x20 [ 36.577806] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 36.582960] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 36.588116] ? find_held_lock+0x39/0x1d0 [ 36.592142] ? lock_downgrade+0x990/0x990 [ 36.596254] ? check_noncircular+0x20/0x20 [ 36.601030] lock_acquire+0x1d5/0x580 [ 36.604801] ? exit_pi_state_list+0x369/0x7a0 [ 36.609263] ? lock_release+0xd70/0xd70 [ 36.613200] ? do_raw_spin_trylock+0x190/0x190 [ 36.617748] ? find_held_lock+0x39/0x1d0 [ 36.621783] _raw_spin_lock_irq+0x5e/0x80 [ 36.625896] ? exit_pi_state_list+0x369/0x7a0 [ 36.630355] exit_pi_state_list+0x369/0x7a0 [ 36.634645] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 36.640667] ? lock_release+0xd70/0xd70 [ 36.644605] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 36.650458] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 36.655535] ? __might_sleep+0x95/0x190 [ 36.659476] ? __might_fault+0x188/0x1d0 [ 36.663501] ? do_raw_spin_trylock+0x190/0x190 [ 36.668136] mm_release+0x46d/0x590 [ 36.671727] ? do_raw_spin_trylock+0x190/0x190 [ 36.676273] ? mm_access+0x140/0x140 [ 36.679950] ? _raw_spin_unlock_irq+0x27/0x70