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-8,10.128.0.56' (ECDSA) to the list of known hosts. 2017/10/01 17:16:20 parsed 1 programs 2017/10/01 17:16:20 executed programs: 0 syzkaller login: [ 51.856163] ================================================================== [ 51.863581] BUG: KASAN: use-after-free in __lock_acquire+0x407b/0x4620 [ 51.870244] Read of size 8 at addr ffff8801c8f670a8 by task syz-executor2/4887 [ 51.877582] [ 51.879197] CPU: 0 PID: 4887 Comm: syz-executor2 Not tainted 4.14.0-rc2-mm1+ #11 [ 51.886700] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.896030] Call Trace: [ 51.898594] dump_stack+0x194/0x257 [ 51.902206] ? arch_local_irq_restore+0x53/0x53 [ 51.906851] ? show_regs_print_info+0x65/0x65 [ 51.911324] ? __kernel_text_address+0xd/0x40 [ 51.915810] ? __lock_acquire+0x407b/0x4620 [ 51.920133] print_address_description+0x73/0x250 [ 51.924955] ? __lock_acquire+0x407b/0x4620 [ 51.929257] kasan_report+0x25b/0x340 [ 51.933047] __asan_report_load8_noabort+0x14/0x20 [ 51.937974] __lock_acquire+0x407b/0x4620 [ 51.942104] ? unwind_dump+0x4c0/0x4c0 [ 51.945962] ? __unwind_start+0x169/0x330 [ 51.950082] ? __kernel_text_address+0xd/0x40 [ 51.954557] ? unwind_get_return_address+0x61/0xa0 [ 51.959467] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 51.964630] ? unwind_get_return_address+0x61/0xa0 [ 51.969543] ? __save_stack_trace+0x61/0xd0 [ 51.973842] ? get_signal+0x73f/0x16d0 [ 51.977701] ? save_stack_trace+0x16/0x20 [ 51.981831] ? __lock_acquire+0x20fd/0x4620 [ 51.986160] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 51.991333] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 51.996496] ? save_stack_trace+0x16/0x20 [ 52.000616] ? __lock_acquire+0x20fd/0x4620 [ 52.004910] ? osq_unlock+0x350/0x350 [ 52.008685] ? save_stack_trace+0x16/0x20 [ 52.012803] ? lock_release+0xd70/0xd70 [ 52.016746] ? check_noncircular+0x20/0x20 [ 52.020964] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 52.026142] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 52.031311] ? find_held_lock+0x39/0x1d0 [ 52.035354] ? lock_downgrade+0x990/0x990 [ 52.039480] ? check_noncircular+0x20/0x20 [ 52.043686] lock_acquire+0x1d5/0x580 [ 52.047456] ? exit_pi_state_list+0x369/0x7a0 [ 52.051924] ? lock_release+0xd70/0xd70 [ 52.055869] ? do_raw_spin_trylock+0x190/0x190 [ 52.060418] ? find_held_lock+0x39/0x1d0 [ 52.064465] _raw_spin_lock_irq+0x5e/0x80 [ 52.068586] ? exit_pi_state_list+0x369/0x7a0 [ 52.073052] exit_pi_state_list+0x369/0x7a0 [ 52.077447] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 52.083497] ? lock_release+0xd70/0xd70 [ 52.087451] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 52.093320] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 52.098397] ? __might_sleep+0x95/0x190 [ 52.102339] ? __might_fault+0x188/0x1d0 [ 52.106378] ? do_raw_spin_trylock+0x190/0x190 [ 52.110931] mm_release+0x46d/0x590 [ 52.114526] ? do_raw_spin_trylock+0x190/0x190 [ 52.119079] ? mm_access+0x140/0x140 [ 52.122760] ? _raw_spin_unlock_irq+0x27/0x70 [ 52.127228] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 52.132224] ? trace_hardirqs_on+0xd/0x10 [ 52.136346] ? _raw_spin_unlock_irq+0x27/0x70 [ 52.140808] ? acct_collect+0x637/0x800 [ 52.144749] do_exit+0x481/0x1b00 [ 52.148177] ? mm_update_next_owner+0x930/0x930 [ 52.152814] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 52.158668] ? find_held_lock+0x39/0x1d0 [ 52.162699] ? refill_pi_state_cache.part.6+0x2f0/0x2f0 [ 52.168037] ? check_noncircular+0x20/0x20 [ 52.172247] ? fault_in_user_writeable+0x90/0x90 [ 52.176969] ? futex_wake+0x680/0x680 [ 52.180737] ? find_held_lock+0x39/0x1d0 [ 52.184765] ? lock_downgrade+0x990/0x990 [ 52.188879] ? recalc_sigpending_tsk+0x117/0x150 [ 52.193601] ? recalc_sigpending+0x103/0x160 [ 52.197975] ? recalc_sigpending_tsk+0x150/0x150 [ 52.202694] ? get_signal+0x2b2/0x16d0 [ 52.206551] do_group_exit+0x149/0x400 [ 52.210402] ? __lock_is_held+0xbc/0x140 [ 52.214426] ? SyS_exit+0x30/0x30 [ 52.217843] ? _raw_spin_unlock_irq+0x27/0x70 [ 52.222303] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 52.227287] get_signal+0x73f/0x16d0 [ 52.230969] ? ptrace_notify+0x130/0x130 [ 52.235000] ? __schedule+0x8f0/0x2070 [ 52.238861] ? exit_robust_list+0x240/0x240 [ 52.243149] ? lock_downgrade+0x990/0x990 [ 52.247263] ? SyS_brk+0x6f0/0x6f0 [ 52.250768] do_signal+0x94/0x1ee0 [ 52.254275] ? arch_get_unmapped_area+0x750/0x750 [ 52.259086] ? lock_acquire+0x1d5/0x580 [ 52.263042] ? find_held_lock+0x39/0x1d0 [ 52.267078] ? setup_sigcontext+0x7d0/0x7d0 [ 52.271368] ? lock_downgrade+0x990/0x990 [ 52.275487] ? down_write+0x120/0x120 [ 52.279254] ? lock_release+0xd70/0xd70 [ 52.283192] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 52.289045] ? vm_mmap_pgoff+0x1fc/0x280 [ 52.293073] ? exit_to_usermode_loop+0x8c/0x310 [ 52.297706] exit_to_usermode_loop+0x214/0x310 [ 52.302258] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 52.307760] ? kasan_check_write+0x14/0x20 [ 52.311962] syscall_return_slowpath+0x42f/0x510 [ 52.316685] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 52.321676] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 52.326577] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 52.331558] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 52.336286] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 52.341006] RIP: 0033:0x4520a9 [ 52.344167] RSP: 002b:00007f942dd6bcf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 52.351837] RAX: fffffffffffffe00 RBX: 0000000000718028 RCX: 00000000004520a9 [ 52.359076] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000718028 [ 52.366333] RBP: 0000000000718000 R08: 0000000000000000 R09: 0000000000000000 [ 52.373567] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 52.380800] R13: 00007ffe97ab5d5f R14: 00007f942dd6c9c0 R15: 0000000000000000 [ 52.388047] [ 52.389646] Allocated by task 4913: [ 52.393240] save_stack_trace+0x16/0x20 [ 52.397185] save_stack+0x43/0xd0 [ 52.400600] kasan_kmalloc+0xad/0xe0 [ 52.404281] kmem_cache_alloc_trace+0x136/0x750 [ 52.408914] refill_pi_state_cache.part.6+0xa5/0x2f0 [ 52.413978] futex_requeue+0x1887/0x2370 [ 52.418023] do_futex+0x7f5/0x20d0 [ 52.421533] SyS_futex+0x260/0x390 [ 52.425045] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 52.429760] [ 52.431353] Freed by task 4900: [ 52.434595] save_stack_trace+0x16/0x20 [ 52.438532] save_stack+0x43/0xd0 [ 52.441947] kasan_slab_free+0x71/0xc0 [ 52.445795] kfree+0xca/0x250 [ 52.448867] put_pi_state+0x3f4/0x560 [ 52.452630] unqueue_me_pi+0x4a/0xc0 [ 52.456306] futex_wait_requeue_pi.constprop.19+0xc7f/0x1300 [ 52.462066] do_futex+0x825/0x20d0 [ 52.465571] SyS_futex+0x260/0x390 [ 52.469075] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 52.473795] [ 52.475981] The buggy address belongs to the object at ffff8801c8f67080 [ 52.475981] which belongs to the cache kmalloc-256 of size 256 [ 52.488601] The buggy address is located 40 bytes inside of [ 52.488601] 256-byte region [ffff8801c8f67080, ffff8801c8f67180) [ 52.500349] The buggy address belongs to the page: [ 52.505244] page:ffffea000723d9c0 count:1 mapcount:0 mapping:ffff8801c8f67080 index:0x0 [ 52.513349] flags: 0x200000000000100(slab) [ 52.517549] raw: 0200000000000100 ffff8801c8f67080 0000000000000000 000000010000000c [ 52.525392] raw: ffffea0007230be0 ffffea00072237e0 ffff8801dac007c0 0000000000000000 [ 52.533233] page dumped because: kasan: bad access detected [ 52.538903] [ 52.540492] Memory state around the buggy address: [ 52.545383] ffff8801c8f66f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 52.552705] ffff8801c8f67000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 52.560031] >ffff8801c8f67080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 52.567359] ^ [ 52.571992] ffff8801c8f67100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 52.579317] ffff8801c8f67180: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 52.586638] ================================================================== [ 52.593957] Disabling lock debugging due to kernel taint [ 52.599370] Kernel panic - not syncing: panic_on_warn set ... [ 52.599370] [ 52.606697] CPU: 0 PID: 4887 Comm: syz-executor2 Tainted: G B 4.14.0-rc2-mm1+ #11 [ 52.615406] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.624724] Call Trace: [ 52.627279] dump_stack+0x194/0x257 [ 52.630872] ? arch_local_irq_restore+0x53/0x53 [ 52.635505] ? vprintk_default+0x28/0x30 [ 52.639530] ? __lock_acquire+0x4060/0x4620 [ 52.643815] panic+0x1e4/0x41c [ 52.646974] ? refcount_error_report+0x214/0x214 [ 52.651698] ? __lock_acquire+0x407b/0x4620 [ 52.655984] kasan_end_report+0x50/0x50 [ 52.659922] kasan_report+0x144/0x340 [ 52.663689] __asan_report_load8_noabort+0x14/0x20 [ 52.668580] __lock_acquire+0x407b/0x4620 [ 52.672692] ? unwind_dump+0x4c0/0x4c0 [ 52.676542] ? __unwind_start+0x169/0x330 [ 52.680653] ? __kernel_text_address+0xd/0x40 [ 52.685119] ? unwind_get_return_address+0x61/0xa0 [ 52.690026] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 52.695179] ? unwind_get_return_address+0x61/0xa0 [ 52.700072] ? __save_stack_trace+0x61/0xd0 [ 52.704359] ? get_signal+0x73f/0x16d0 [ 52.708211] ? save_stack_trace+0x16/0x20 [ 52.712323] ? __lock_acquire+0x20fd/0x4620 [ 52.716610] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 52.721766] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 52.726918] ? save_stack_trace+0x16/0x20 [ 52.731034] ? __lock_acquire+0x20fd/0x4620 [ 52.735321] ? osq_unlock+0x350/0x350 [ 52.739084] ? save_stack_trace+0x16/0x20 [ 52.743195] ? lock_release+0xd70/0xd70 [ 52.747134] ? check_noncircular+0x20/0x20 [ 52.751334] ? debug_check_no_locks_freed+0x3d0/0x3d0