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-3,10.128.0.17' (ECDSA) to the list of known hosts. 2017/09/30 16:44:56 parsed 1 programs 2017/09/30 16:44:56 executed programs: 0 syzkaller login: [ 30.655451] ================================================================== [ 30.662868] BUG: KASAN: use-after-free in __lock_acquire+0x407b/0x4620 [ 30.669501] Read of size 8 at addr ffff8801d2a7be68 by task syz-executor4/3028 [ 30.676825] [ 30.678424] CPU: 0 PID: 3028 Comm: syz-executor4 Not tainted 4.14.0-rc2-mm1+ #11 [ 30.685922] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.695244] Call Trace: [ 30.697801] dump_stack+0x194/0x257 [ 30.701394] ? arch_local_irq_restore+0x53/0x53 [ 30.706029] ? show_regs_print_info+0x65/0x65 [ 30.710492] ? __kernel_text_address+0xd/0x40 [ 30.714952] ? __lock_acquire+0x407b/0x4620 [ 30.719241] print_address_description+0x73/0x250 [ 30.724048] ? __lock_acquire+0x407b/0x4620 [ 30.728333] kasan_report+0x25b/0x340 [ 30.732100] __asan_report_load8_noabort+0x14/0x20 [ 30.736994] __lock_acquire+0x407b/0x4620 [ 30.741110] ? unwind_dump+0x4c0/0x4c0 [ 30.744961] ? __unwind_start+0x169/0x330 [ 30.749074] ? __kernel_text_address+0xd/0x40 [ 30.753533] ? unwind_get_return_address+0x61/0xa0 [ 30.758429] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 30.763585] ? unwind_get_return_address+0x61/0xa0 [ 30.768481] ? __save_stack_trace+0x61/0xd0 [ 30.772778] ? get_signal+0x73f/0x16d0 [ 30.776630] ? save_stack_trace+0x16/0x20 [ 30.780742] ? __lock_acquire+0x20fd/0x4620 [ 30.785031] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 30.790188] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 30.795344] ? save_stack_trace+0x16/0x20 [ 30.799455] ? __lock_acquire+0x20fd/0x4620 [ 30.803741] ? osq_unlock+0x350/0x350 [ 30.807504] ? save_stack_trace+0x16/0x20 [ 30.811616] ? lock_release+0xd70/0xd70 [ 30.815556] ? check_noncircular+0x20/0x20 [ 30.819755] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 30.824909] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 30.830066] ? find_held_lock+0x39/0x1d0 [ 30.834105] ? lock_downgrade+0x990/0x990 [ 30.838217] ? check_noncircular+0x20/0x20 [ 30.842416] lock_acquire+0x1d5/0x580 [ 30.846185] ? exit_pi_state_list+0x369/0x7a0 [ 30.850648] ? lock_release+0xd70/0xd70 [ 30.854587] ? do_raw_spin_trylock+0x190/0x190 [ 30.859132] ? find_held_lock+0x39/0x1d0 [ 30.863169] _raw_spin_lock_irq+0x5e/0x80 [ 30.867293] ? exit_pi_state_list+0x369/0x7a0 [ 30.871756] exit_pi_state_list+0x369/0x7a0 [ 30.876047] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 30.882080] ? lock_release+0xd70/0xd70 [ 30.886026] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 30.891896] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 30.896966] ? __might_sleep+0x95/0x190 [ 30.900907] ? __might_fault+0x188/0x1d0 [ 30.904934] ? do_raw_spin_trylock+0x190/0x190 [ 30.909482] mm_release+0x46d/0x590 [ 30.913074] ? do_raw_spin_trylock+0x190/0x190 [ 30.917622] ? mm_access+0x140/0x140 [ 30.921303] ? _raw_spin_unlock_irq+0x27/0x70 [ 30.925768] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 30.930756] ? trace_hardirqs_on+0xd/0x10 [ 30.934884] ? _raw_spin_unlock_irq+0x27/0x70 [ 30.939366] ? acct_collect+0x637/0x800 [ 30.943306] do_exit+0x481/0x1b00 [ 30.946736] ? mm_update_next_owner+0x930/0x930 [ 30.951372] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 30.957222] ? find_held_lock+0x39/0x1d0 [ 30.961252] ? refill_pi_state_cache.part.6+0x2f0/0x2f0 [ 30.966582] ? check_noncircular+0x20/0x20 [ 30.970785] ? fault_in_user_writeable+0x90/0x90 [ 30.975507] ? futex_wake+0x680/0x680 [ 30.979275] ? find_held_lock+0x39/0x1d0 [ 30.983316] ? lock_downgrade+0x990/0x990 [ 30.987431] ? recalc_sigpending_tsk+0x117/0x150 [ 30.992157] ? recalc_sigpending+0x103/0x160 [ 30.996531] ? recalc_sigpending_tsk+0x150/0x150 [ 31.001252] ? get_signal+0x2b2/0x16d0 [ 31.005125] do_group_exit+0x149/0x400 [ 31.008987] ? __lock_is_held+0xbc/0x140 [ 31.013016] ? SyS_exit+0x30/0x30 [ 31.016440] ? _raw_spin_unlock_irq+0x27/0x70 [ 31.020901] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 31.025886] get_signal+0x73f/0x16d0 [ 31.029573] ? ptrace_notify+0x130/0x130 [ 31.033608] ? exit_robust_list+0x240/0x240 [ 31.037897] ? wake_up_q+0x8a/0xe0 [ 31.041404] ? rwsem_wake+0x313/0x520 [ 31.045176] ? SyS_brk+0x6f0/0x6f0 [ 31.048686] do_signal+0x94/0x1ee0 [ 31.052195] ? arch_get_unmapped_area+0x750/0x750 [ 31.057002] ? lock_acquire+0x1d5/0x580 [ 31.060940] ? vm_mmap_pgoff+0x198/0x280 [ 31.064983] ? userfaultfd_unmap_complete+0x327/0x510 [ 31.070152] ? setup_sigcontext+0x7d0/0x7d0 [ 31.074440] ? userfaultfd_unmap_prep+0x540/0x540 [ 31.079250] ? call_rwsem_wake+0x1b/0x30 [ 31.083277] ? vma_compute_subtree_gap+0x200/0x200 [ 31.088183] ? up_write+0xd8/0x120 [ 31.091700] ? down_write+0x120/0x120 [ 31.095467] ? security_mmap_file+0x143/0x180 [ 31.099928] ? vm_mmap_pgoff+0x1fc/0x280 [ 31.103958] ? exit_to_usermode_loop+0x8c/0x310 [ 31.108592] exit_to_usermode_loop+0x214/0x310 [ 31.113141] ? vma_is_stack_for_current+0xa0/0xa0 [ 31.117952] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 31.123467] ? kasan_check_write+0x14/0x20 [ 31.127674] syscall_return_slowpath+0x42f/0x510 [ 31.132398] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 31.137384] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 31.142283] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 31.147279] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 31.152008] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 31.156732] RIP: 0033:0x4520a9 [ 31.159889] RSP: 002b:00007f7c6af17cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 31.167576] RAX: fffffffffffffe00 RBX: 0000000000718188 RCX: 00000000004520a9 [ 31.174815] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000718188 [ 31.182056] RBP: 0000000000718160 R08: 0000000000000000 R09: 0000000000000000 [ 31.189305] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 31.196544] R13: 0000000000a6f7ef R14: 00007f7c6af189c0 R15: 0000000000000003 [ 31.203788] [ 31.205406] Allocated by task 3042: [ 31.209008] save_stack_trace+0x16/0x20 [ 31.212951] save_stack+0x43/0xd0 [ 31.216470] kasan_kmalloc+0xad/0xe0 [ 31.220151] kmem_cache_alloc_trace+0x136/0x750 [ 31.224787] refill_pi_state_cache.part.6+0xa5/0x2f0 [ 31.229858] futex_requeue+0x1887/0x2370 [ 31.233888] do_futex+0x7f5/0x20d0 [ 31.237394] SyS_futex+0x260/0x390 [ 31.240908] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 31.245626] [ 31.247222] Freed by task 3021: [ 31.250482] save_stack_trace+0x16/0x20 [ 31.254429] save_stack+0x43/0xd0 [ 31.257848] kasan_slab_free+0x71/0xc0 [ 31.261702] kfree+0xca/0x250 [ 31.264777] put_pi_state+0x3f4/0x560 [ 31.268546] unqueue_me_pi+0x4a/0xc0 [ 31.272225] futex_wait_requeue_pi.constprop.19+0xc7f/0x1300 [ 31.278006] do_futex+0x825/0x20d0 [ 31.281515] SyS_futex+0x260/0x390 [ 31.285025] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 31.289749] [ 31.291346] The buggy address belongs to the object at ffff8801d2a7be40 [ 31.291346] which belongs to the cache kmalloc-256 of size 256 [ 31.303966] The buggy address is located 40 bytes inside of [ 31.303966] 256-byte region [ffff8801d2a7be40, ffff8801d2a7bf40) [ 31.316332] The buggy address belongs to the page: [ 31.321238] page:ffffea00074a9ec0 count:1 mapcount:0 mapping:ffff8801d2a7b080 index:0x0 [ 31.329347] flags: 0x200000000000100(slab) [ 31.333549] raw: 0200000000000100 ffff8801d2a7b080 0000000000000000 000000010000000c [ 31.341397] raw: ffffea00074aa1e0 ffffea0007474c60 ffff8801dac007c0 0000000000000000 [ 31.349242] page dumped because: kasan: bad access detected [ 31.354923] [ 31.356516] Memory state around the buggy address: [ 31.361409] ffff8801d2a7bd00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 31.368742] ffff8801d2a7bd80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc [ 31.376067] >ffff8801d2a7be00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 31.383398] ^ [ 31.390121] ffff8801d2a7be80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 31.397445] ffff8801d2a7bf00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 31.404766] ================================================================== [ 31.412090] Disabling lock debugging due to kernel taint [ 31.417509] Kernel panic - not syncing: panic_on_warn set ... [ 31.417509] [ 31.424849] CPU: 0 PID: 3028 Comm: syz-executor4 Tainted: G B 4.14.0-rc2-mm1+ #11 [ 31.433570] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.442899] Call Trace: [ 31.445461] dump_stack+0x194/0x257 [ 31.449056] ? arch_local_irq_restore+0x53/0x53 [ 31.453694] ? vprintk_default+0x28/0x30 [ 31.457725] ? __lock_acquire+0x4060/0x4620 [ 31.462015] panic+0x1e4/0x41c [ 31.465175] ? refcount_error_report+0x214/0x214 [ 31.469911] ? __lock_acquire+0x407b/0x4620 [ 31.474201] kasan_end_report+0x50/0x50 [ 31.478142] kasan_report+0x144/0x340 [ 31.481920] __asan_report_load8_noabort+0x14/0x20 [ 31.486824] __lock_acquire+0x407b/0x4620 [ 31.490948] ? unwind_dump+0x4c0/0x4c0 [ 31.494801] ? __unwind_start+0x169/0x330 [ 31.498915] ? __kernel_text_address+0xd/0x40 [ 31.503375] ? unwind_get_return_address+0x61/0xa0 [ 31.508272] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 31.513425] ? unwind_get_return_address+0x61/0xa0 [ 31.518331] ? __save_stack_trace+0x61/0xd0 [ 31.522624] ? get_signal+0x73f/0x16d0 [ 31.526482] ? save_stack_trace+0x16/0x20 [ 31.530597] ? __lock_acquire+0x20fd/0x4620 [ 31.534885] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 31.540043] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 31.545200] ? save_stack_trace+0x16/0x20 [ 31.549313] ? __lock_acquire+0x20fd/0x4620 [ 31.553687] ? osq_unlock+0x350/0x350 [ 31.557451] ? save_stack_trace+0x16/0x20 [ 31.561567] ? lock_release+0xd70/0xd70 [ 31.565506] ? check_noncircular+0x20/0x20 [ 31.569706] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 31.574862] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 31.580020] ? find_held_lock+0x39/0x1d0 [ 31.584060] ? lock_downgrade+0x990/0x990 [ 31.588175] ? check_noncircular+0x20/0x20 [ 31.592375] lock_acquire+0x1d5/0x580 [ 31.596155] ? exit_pi_state_list+0x369/0x7a0 [ 31.600619] ? lock_release+0xd70/0xd70 [ 31.604559] ? do_raw_spin_trylock+0x190/0x190 [ 31.609105] ? find_held_lock+0x39/0x1d0 [ 31.613138] _raw_spin_lock_irq+0x5e/0x80 [ 31.617262] ? exit_pi_state_list+0x369/0x7a0 [ 31.621725] exit_pi_state_list+0x369/0x7a0 [ 31.626018] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 31.632043] ? lock_release+0xd70/0xd70 [ 31.635983] ? trace_event_raw_event_sched_switch+0x770/0x770 [ 31.641833] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 31.646915] ? __might_sleep+0x95/0x190 [ 31.650871] ? __might_fault+0x188/0x1d0 [ 31.654902] ? do_raw_spin_trylock+0x190/0x190