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-386-0,10.128.0.14' (ECDSA) to the list of known hosts. 2017/10/04 14:11:46 parsed 1 programs 2017/10/04 14:11:46 executed programs: 0 syzkaller login: [ 35.753070] ================================================================== [ 35.760471] BUG: KASAN: use-after-free in __lock_acquire+0x407b/0x4620 [ 35.767100] Read of size 8 at addr ffff8801ceb881e8 by task syz-executor0/3005 [ 35.774421] [ 35.776015] CPU: 0 PID: 3005 Comm: syz-executor0 Not tainted 4.14.0-rc3+ #24 [ 35.783163] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.792481] Call Trace: [ 35.795035] dump_stack+0x194/0x257 [ 35.798629] ? arch_local_irq_restore+0x53/0x53 [ 35.803262] ? show_regs_print_info+0x65/0x65 [ 35.807723] ? __kernel_text_address+0xd/0x40 [ 35.812185] ? __lock_acquire+0x407b/0x4620 [ 35.816469] print_address_description+0x73/0x250 [ 35.821277] ? __lock_acquire+0x407b/0x4620 [ 35.825561] kasan_report+0x25b/0x340 [ 35.829324] __asan_report_load8_noabort+0x14/0x20 [ 35.834216] __lock_acquire+0x407b/0x4620 [ 35.838327] ? unwind_dump+0x4c0/0x4c0 [ 35.842181] ? __kernel_text_address+0xd/0x40 [ 35.846638] ? unwind_get_return_address+0x61/0xa0 [ 35.851532] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.856687] ? __save_stack_trace+0x61/0xd0 [ 35.860973] ? get_signal+0x73f/0x16d0 [ 35.864825] ? save_stack_trace+0x16/0x20 [ 35.869409] ? __lock_acquire+0x20fd/0x4620 [ 35.873694] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.878850] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.884002] ? save_stack_trace+0x16/0x20 [ 35.888110] ? __lock_acquire+0x20fd/0x4620 [ 35.892395] ? osq_unlock+0x350/0x350 [ 35.896155] ? save_stack_trace+0x16/0x20 [ 35.900272] ? check_noncircular+0x20/0x20 [ 35.904472] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.909623] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 35.914778] ? __unwind_start+0x169/0x330 [ 35.918889] ? find_held_lock+0x39/0x1d0 [ 35.922913] ? lock_downgrade+0x990/0x990 [ 35.927024] ? check_noncircular+0x20/0x20 [ 35.931222] lock_acquire+0x1d5/0x580 [ 35.934986] ? exit_pi_state_list+0x369/0x7a0 [ 35.939444] ? lock_release+0xd70/0xd70 [ 35.943382] ? do_raw_spin_trylock+0x190/0x190 [ 35.947924] ? find_held_lock+0x39/0x1d0 [ 35.951953] _raw_spin_lock_irq+0x5e/0x80 [ 35.956063] ? exit_pi_state_list+0x369/0x7a0 [ 35.960518] exit_pi_state_list+0x369/0x7a0 [ 35.964804] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 35.970824] ? lock_release+0xd70/0xd70 [ 35.974764] ? check_same_owner+0x320/0x320 [ 35.979048] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 35.984115] ? __might_sleep+0x95/0x190 [ 35.988052] ? __might_fault+0x188/0x1d0 [ 35.992076] ? do_raw_spin_trylock+0x190/0x190 [ 35.996621] mm_release+0x46d/0x590 [ 36.000211] ? mm_access+0x140/0x140 [ 36.003886] ? _raw_spin_unlock_irq+0x27/0x70 [ 36.008342] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 36.013319] ? trace_hardirqs_on+0xd/0x10 [ 36.017427] ? _raw_spin_unlock_irq+0x27/0x70 [ 36.021883] ? acct_collect+0x637/0x800 [ 36.025819] do_exit+0x481/0x1af0 [ 36.029236] ? mm_update_next_owner+0x930/0x930 [ 36.033865] ? lock_downgrade+0x990/0x990 [ 36.037975] ? refill_pi_state_cache.part.6+0x2f0/0x2f0 [ 36.043299] ? futex_wait+0x3ad/0x990 [ 36.047064] ? do_raw_spin_trylock+0x190/0x190 [ 36.051609] ? fault_in_user_writeable+0x90/0x90 [ 36.056326] ? futex_wake+0x680/0x680 [ 36.060087] ? fault_in_user_writeable+0x90/0x90 [ 36.064804] ? check_noncircular+0x20/0x20 [ 36.069000] ? drop_futex_key_refs.isra.13+0x63/0xb0 [ 36.074065] ? futex_wait+0x69e/0x990 [ 36.077829] ? futex_wait_setup+0x3d0/0x3d0 [ 36.082113] ? find_held_lock+0x39/0x1d0 [ 36.086141] ? lock_downgrade+0x990/0x990 [ 36.090254] ? recalc_sigpending_tsk+0x117/0x150 [ 36.094972] ? recalc_sigpending+0x103/0x160 [ 36.099344] ? recalc_sigpending_tsk+0x150/0x150 [ 36.104066] ? get_signal+0x2b2/0x16d0 [ 36.107920] do_group_exit+0x149/0x400 [ 36.111770] ? __lock_is_held+0xbc/0x140 [ 36.115794] ? SyS_exit+0x30/0x30 [ 36.119212] ? _raw_spin_unlock_irq+0x27/0x70 [ 36.123668] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 36.128648] get_signal+0x73f/0x16d0 [ 36.132325] ? ptrace_notify+0x130/0x130 [ 36.136350] ? lock_downgrade+0x990/0x990 [ 36.140459] ? SyS_brk+0x6f0/0x6f0 [ 36.143963] ? arch_get_unmapped_area+0x750/0x750 [ 36.148766] ? lock_acquire+0x1d5/0x580 [ 36.152702] ? vm_mmap_pgoff+0x198/0x280 [ 36.156729] ? userfaultfd_unmap_complete+0x327/0x510 [ 36.161883] do_signal+0x94/0x1ee0 [ 36.165386] ? do_mmap+0x34f/0xd50 [ 36.168891] ? up_write+0x6b/0x120 [ 36.172394] ? setup_sigcontext+0x7d0/0x7d0 [ 36.176679] ? security_mmap_file+0x143/0x180 [ 36.181137] ? vm_mmap_pgoff+0x1fc/0x280 [ 36.185163] ? vm_mmap_pgoff+0x13b/0x280 [ 36.189186] ? vma_is_stack_for_current+0xa0/0xa0 [ 36.193990] ? find_held_lock+0x39/0x1d0 [ 36.198015] ? __compat_get_timespec+0xd9/0x120 [ 36.202648] ? exit_to_usermode_loop+0x8c/0x310 [ 36.207283] exit_to_usermode_loop+0x214/0x310 [ 36.211826] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 36.217323] ? lock_acquire+0x1d5/0x580 [ 36.221258] ? do_fast_syscall_32+0x158/0xf05 [ 36.225717] do_fast_syscall_32+0x83e/0xf05 [ 36.230002] ? compat_start_thread+0x80/0x80 [ 36.234375] ? do_int80_syscall_32+0x940/0x940 [ 36.238921] ? lockdep_sys_exit+0x47/0xf0 [ 36.243030] ? syscall_return_slowpath+0x2b3/0x510 [ 36.247920] ? finish_task_switch+0x1aa/0x740 [ 36.252377] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 36.257353] ? sysret32_from_system_call+0x5/0x3b [ 36.262158] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 36.266961] entry_SYSENTER_compat+0x51/0x60 [ 36.271330] RIP: 0023:0xf7fa6c79 [ 36.274657] RSP: 002b:00000000f7fa212c EFLAGS: 00000292 ORIG_RAX: 00000000000000f0 [ 36.282328] RAX: fffffffffffffe00 RBX: 0000000008128018 RCX: 0000000000000000 [ 36.289559] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 36.296793] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 36.304027] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 36.311262] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 36.318498] [ 36.320089] Allocated by task 3032: [ 36.323679] save_stack_trace+0x16/0x20 [ 36.327614] save_stack+0x43/0xd0 [ 36.331030] kasan_kmalloc+0xad/0xe0 [ 36.334705] kmem_cache_alloc_trace+0x136/0x750 [ 36.339335] refill_pi_state_cache.part.6+0xa5/0x2f0 [ 36.344398] futex_requeue+0x1887/0x2370 [ 36.348419] do_futex+0x7f5/0x20d0 [ 36.351919] compat_SyS_futex+0x27f/0x380 [ 36.356029] do_fast_syscall_32+0x3f2/0xf05 [ 36.360310] entry_SYSENTER_compat+0x51/0x60 [ 36.364675] [ 36.366266] Freed by task 3023: [ 36.369506] save_stack_trace+0x16/0x20 [ 36.373444] save_stack+0x43/0xd0 [ 36.376859] kasan_slab_free+0x71/0xc0 [ 36.380705] kfree+0xca/0x250 [ 36.383771] put_pi_state+0x3f4/0x560 [ 36.387533] unqueue_me_pi+0x4a/0xc0 [ 36.391211] futex_wait_requeue_pi.constprop.19+0xc7f/0x1300 [ 36.396969] do_futex+0x825/0x20d0 [ 36.400470] compat_SyS_futex+0x27f/0x380 [ 36.404579] do_fast_syscall_32+0x3f2/0xf05 [ 36.408863] entry_SYSENTER_compat+0x51/0x60 [ 36.413229] [ 36.414819] The buggy address belongs to the object at ffff8801ceb881c0 [ 36.414819] which belongs to the cache kmalloc-256 of size 256 [ 36.427434] The buggy address is located 40 bytes inside of [ 36.427434] 256-byte region [ffff8801ceb881c0, ffff8801ceb882c0) [ 36.439182] The buggy address belongs to the page: [ 36.444073] page:ffffea00073ae200 count:1 mapcount:0 mapping:ffff8801ceb88080 index:0x0 [ 36.452176] flags: 0x200000000000100(slab) [ 36.456373] raw: 0200000000000100 ffff8801ceb88080 0000000000000000 000000010000000c [ 36.464218] raw: ffffea00073a0ca0 ffffea0007383860 ffff8801dac007c0 0000000000000000 [ 36.472058] page dumped because: kasan: bad access detected [ 36.477728] [ 36.479317] Memory state around the buggy address: [ 36.484208] ffff8801ceb88080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 36.491527] ffff8801ceb88100: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 36.498846] >ffff8801ceb88180: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 36.506165] ^ [ 36.512879] ffff8801ceb88200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 36.520199] ffff8801ceb88280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 36.527517] ================================================================== [ 36.534836] Disabling lock debugging due to kernel taint [ 36.540248] Kernel panic - not syncing: panic_on_warn set ... [ 36.540248] [ 36.547571] CPU: 0 PID: 3005 Comm: syz-executor0 Tainted: G B 4.14.0-rc3+ #24 [ 36.555932] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 36.565247] Call Trace: [ 36.567798] dump_stack+0x194/0x257 [ 36.571387] ? arch_local_irq_restore+0x53/0x53 [ 36.576027] ? vprintk_default+0x28/0x30 [ 36.580053] ? __lock_acquire+0x3ff0/0x4620 [ 36.584336] panic+0x1e4/0x417 [ 36.587491] ? __warn+0x1d9/0x1d9 [ 36.590929] ? __lock_acquire+0x407b/0x4620 [ 36.595215] kasan_end_report+0x50/0x50 [ 36.599153] kasan_report+0x144/0x340 [ 36.602919] __asan_report_load8_noabort+0x14/0x20 [ 36.607809] __lock_acquire+0x407b/0x4620 [ 36.611918] ? unwind_dump+0x4c0/0x4c0 [ 36.615769] ? __kernel_text_address+0xd/0x40 [ 36.620228] ? unwind_get_return_address+0x61/0xa0 [ 36.625123] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 36.630276] ? __save_stack_trace+0x61/0xd0 [ 36.634562] ? get_signal+0x73f/0x16d0 [ 36.638414] ? save_stack_trace+0x16/0x20 [ 36.642525] ? __lock_acquire+0x20fd/0x4620 [ 36.646814] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 36.651970] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 36.657123] ? save_stack_trace+0x16/0x20 [ 36.661232] ? __lock_acquire+0x20fd/0x4620 [ 36.665516] ? osq_unlock+0x350/0x350 [ 36.669277] ? save_stack_trace+0x16/0x20 [ 36.673392] ? check_noncircular+0x20/0x20 [ 36.677590] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 36.682742] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 36.687894] ? __unwind_start+0x169/0x330 [ 36.692006] ? find_held_lock+0x39/0x1d0 [ 36.696031] ? lock_downgrade+0x990/0x990 [ 36.700146] ? check_noncircular+0x20/0x20 [ 36.704349] lock_acquire+0x1d5/0x580 [ 36.708114] ? exit_pi_state_list+0x369/0x7a0 [ 36.712575] ? lock_release+0xd70/0xd70 [ 36.716510] ? do_raw_spin_trylock+0x190/0x190 [ 36.721052] ? find_held_lock+0x39/0x1d0 [ 36.725080] _raw_spin_lock_irq+0x5e/0x80 [ 36.729192] ? exit_pi_state_list+0x369/0x7a0 [ 36.733648] exit_pi_state_list+0x369/0x7a0 [ 36.737933] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 36.743952] ? lock_release+0xd70/0xd70 [ 36.747893] ? check_same_owner+0x320/0x320 [ 36.752177] ? _raw_spin_unlock_irqrestore+0x31/0xba