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-386-4,10.128.0.60' (ECDSA) to the list of known hosts. 2017/10/04 05:22:20 parsed 1 programs 2017/10/04 05:22:20 executed programs: 0 syzkaller login: [ 43.715819] ================================================================== [ 43.723430] BUG: KASAN: use-after-free in __lock_acquire+0x407b/0x4620 [ 43.730060] Read of size 8 at addr ffff8801ccc03168 by task syz-executor1/3646 [ 43.737384] [ 43.738979] CPU: 1 PID: 3646 Comm: syz-executor1 Not tainted 4.14.0-rc3+ #23 [ 43.746130] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.755452] Call Trace: [ 43.758006] dump_stack+0x194/0x257 [ 43.761597] ? arch_local_irq_restore+0x53/0x53 [ 43.766232] ? show_regs_print_info+0x65/0x65 [ 43.771157] ? __kernel_text_address+0xd/0x40 [ 43.775704] ? __lock_acquire+0x407b/0x4620 [ 43.779990] print_address_description+0x73/0x250 [ 43.784800] ? __lock_acquire+0x407b/0x4620 [ 43.789085] kasan_report+0x25b/0x340 [ 43.792850] __asan_report_load8_noabort+0x14/0x20 [ 43.797760] __lock_acquire+0x407b/0x4620 [ 43.801874] ? unwind_dump+0x4c0/0x4c0 [ 43.805724] ? __kernel_text_address+0xd/0x40 [ 43.810184] ? unwind_get_return_address+0x61/0xa0 [ 43.815080] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 43.820234] ? __save_stack_trace+0x61/0xd0 [ 43.824518] ? get_signal+0x73f/0x16d0 [ 43.828372] ? save_stack_trace+0x16/0x20 [ 43.832483] ? __lock_acquire+0x20fd/0x4620 [ 43.836772] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 43.841927] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 43.847085] ? save_stack_trace+0x16/0x20 [ 43.851199] ? __lock_acquire+0x20fd/0x4620 [ 43.855484] ? osq_unlock+0x350/0x350 [ 43.859247] ? save_stack_trace+0x16/0x20 [ 43.863369] ? check_noncircular+0x20/0x20 [ 43.867579] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 43.872733] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 43.877886] ? __unwind_start+0x169/0x330 [ 43.882001] ? find_held_lock+0x39/0x1d0 [ 43.886039] ? lock_downgrade+0x990/0x990 [ 43.890162] ? check_noncircular+0x20/0x20 [ 43.894374] lock_acquire+0x1d5/0x580 [ 43.898139] ? exit_pi_state_list+0x369/0x7a0 [ 43.902599] ? lock_release+0xd70/0xd70 [ 43.906535] ? do_raw_spin_trylock+0x190/0x190 [ 43.911080] ? find_held_lock+0x39/0x1d0 [ 43.915112] _raw_spin_lock_irq+0x5e/0x80 [ 43.919223] ? exit_pi_state_list+0x369/0x7a0 [ 43.923681] exit_pi_state_list+0x369/0x7a0 [ 43.927968] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 43.933990] ? lock_release+0xd70/0xd70 [ 43.937932] ? check_same_owner+0x320/0x320 [ 43.942219] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 43.947304] ? __might_sleep+0x95/0x190 [ 43.951260] ? __might_fault+0x188/0x1d0 [ 43.955296] ? do_raw_spin_trylock+0x190/0x190 [ 43.959844] mm_release+0x46d/0x590 [ 43.963432] ? do_raw_spin_trylock+0x190/0x190 [ 43.967982] ? mm_access+0x140/0x140 [ 43.971662] ? _raw_spin_unlock_irq+0x27/0x70 [ 43.976298] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 43.981276] ? trace_hardirqs_on+0xd/0x10 [ 43.985389] ? _raw_spin_unlock_irq+0x27/0x70 [ 43.989851] ? acct_collect+0x637/0x800 [ 43.993789] do_exit+0x481/0x1af0 [ 43.997208] ? mm_update_next_owner+0x930/0x930 [ 44.001839] ? lock_downgrade+0x990/0x990 [ 44.005951] ? refill_pi_state_cache.part.6+0x2f0/0x2f0 [ 44.011278] ? futex_wait+0x3ad/0x990 [ 44.015044] ? do_raw_spin_trylock+0x190/0x190 [ 44.019593] ? fault_in_user_writeable+0x90/0x90 [ 44.024329] ? futex_wake+0x680/0x680 [ 44.028093] ? fault_in_user_writeable+0x90/0x90 [ 44.032811] ? check_noncircular+0x20/0x20 [ 44.037013] ? drop_futex_key_refs.isra.13+0x63/0xb0 [ 44.042181] ? futex_wait+0x69e/0x990 [ 44.045950] ? futex_wait_setup+0x3d0/0x3d0 [ 44.050236] ? find_held_lock+0x39/0x1d0 [ 44.054262] ? lock_downgrade+0x990/0x990 [ 44.058392] ? recalc_sigpending_tsk+0x117/0x150 [ 44.063112] ? recalc_sigpending+0x103/0x160 [ 44.067484] ? recalc_sigpending_tsk+0x150/0x150 [ 44.072203] ? get_signal+0x2b2/0x16d0 [ 44.076060] do_group_exit+0x149/0x400 [ 44.079911] ? __lock_is_held+0xbc/0x140 [ 44.083938] ? SyS_exit+0x30/0x30 [ 44.087360] ? _raw_spin_unlock_irq+0x27/0x70 [ 44.091822] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 44.096805] get_signal+0x73f/0x16d0 [ 44.100486] ? ptrace_notify+0x130/0x130 [ 44.104511] ? lock_downgrade+0x990/0x990 [ 44.108624] ? SyS_brk+0x6f0/0x6f0 [ 44.112130] ? arch_get_unmapped_area+0x750/0x750 [ 44.116937] ? lock_acquire+0x1d5/0x580 [ 44.120874] ? vm_mmap_pgoff+0x198/0x280 [ 44.124898] ? userfaultfd_unmap_complete+0x327/0x510 [ 44.130058] do_signal+0x94/0x1ee0 [ 44.133571] ? do_mmap+0x34f/0xd50 [ 44.137078] ? up_write+0x6b/0x120 [ 44.140591] ? setup_sigcontext+0x7d0/0x7d0 [ 44.144877] ? security_mmap_file+0x143/0x180 [ 44.149340] ? vm_mmap_pgoff+0x1fc/0x280 [ 44.153363] ? vm_mmap_pgoff+0x13b/0x280 [ 44.157391] ? vma_is_stack_for_current+0xa0/0xa0 [ 44.162204] ? find_held_lock+0x39/0x1d0 [ 44.166228] ? __compat_get_timespec+0xd9/0x120 [ 44.170864] ? exit_to_usermode_loop+0x8c/0x310 [ 44.175497] exit_to_usermode_loop+0x214/0x310 [ 44.180043] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 44.185546] ? lock_acquire+0x1d5/0x580 [ 44.189484] ? do_fast_syscall_32+0x158/0xf05 [ 44.193948] do_fast_syscall_32+0x83e/0xf05 [ 44.198235] ? compat_start_thread+0x80/0x80 [ 44.202611] ? do_int80_syscall_32+0x940/0x940 [ 44.207163] ? lockdep_sys_exit+0x47/0xf0 [ 44.211274] ? syscall_return_slowpath+0x2b3/0x510 [ 44.216166] ? finish_task_switch+0x1aa/0x740 [ 44.220624] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 44.225609] ? sysret32_from_system_call+0x5/0x3b [ 44.230416] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 44.235225] entry_SYSENTER_compat+0x51/0x60 [ 44.239596] RIP: 0023:0xf7fa2c79 [ 44.242926] RSP: 002b:00000000f7f9e12c EFLAGS: 00000292 ORIG_RAX: 00000000000000f0 [ 44.250597] RAX: fffffffffffffe00 RBX: 0000000008128018 RCX: 0000000000000000 [ 44.257830] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 44.265067] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 44.272300] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 44.279535] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 44.286783] [ 44.288376] Allocated by task 3676: [ 44.291982] save_stack_trace+0x16/0x20 [ 44.295923] save_stack+0x43/0xd0 [ 44.299338] kasan_kmalloc+0xad/0xe0 [ 44.303013] kmem_cache_alloc_trace+0x136/0x750 [ 44.307660] refill_pi_state_cache.part.6+0xa5/0x2f0 [ 44.312723] futex_requeue+0x1887/0x2370 [ 44.316745] do_futex+0x7f5/0x20d0 [ 44.320247] compat_SyS_futex+0x27f/0x380 [ 44.324357] do_fast_syscall_32+0x3f2/0xf05 [ 44.329484] entry_SYSENTER_compat+0x51/0x60 [ 44.333852] [ 44.335444] Freed by task 3665: [ 44.338688] save_stack_trace+0x16/0x20 [ 44.342625] save_stack+0x43/0xd0 [ 44.346044] kasan_slab_free+0x71/0xc0 [ 44.349893] kfree+0xca/0x250 [ 44.352960] put_pi_state+0x3f4/0x560 [ 44.356726] unqueue_me_pi+0x4a/0xc0 [ 44.360403] futex_wait_requeue_pi.constprop.19+0xc7f/0x1300 [ 44.366160] do_futex+0x825/0x20d0 [ 44.369661] compat_SyS_futex+0x27f/0x380 [ 44.373771] do_fast_syscall_32+0x3f2/0xf05 [ 44.378065] entry_SYSENTER_compat+0x51/0x60 [ 44.382433] [ 44.384025] The buggy address belongs to the object at ffff8801ccc03140 [ 44.384025] which belongs to the cache kmalloc-256 of size 256 [ 44.396647] The buggy address is located 40 bytes inside of [ 44.396647] 256-byte region [ffff8801ccc03140, ffff8801ccc03240) [ 44.408394] The buggy address belongs to the page: [ 44.413286] page:ffffea00073300c0 count:1 mapcount:0 mapping:ffff8801ccc03000 index:0x0 [ 44.421407] flags: 0x200000000000100(slab) [ 44.425693] raw: 0200000000000100 ffff8801ccc03000 0000000000000000 000000010000000c [ 44.433538] raw: ffffea0007374ea0 ffffea0007338fa0 ffff8801dac007c0 0000000000000000 [ 44.441380] page dumped because: kasan: bad access detected [ 44.447061] [ 44.448651] Memory state around the buggy address: [ 44.453542] ffff8801ccc03000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.460863] ffff8801ccc03080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.468272] >ffff8801ccc03100: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 44.475593] ^ [ 44.482306] ffff8801ccc03180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.489630] ffff8801ccc03200: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 44.497039] ================================================================== [ 44.504360] Disabling lock debugging due to kernel taint [ 44.509772] Kernel panic - not syncing: panic_on_warn set ... [ 44.509772] [ 44.517096] CPU: 1 PID: 3646 Comm: syz-executor1 Tainted: G B 4.14.0-rc3+ #23 [ 44.525459] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.534777] Call Trace: [ 44.537332] dump_stack+0x194/0x257 [ 44.540928] ? arch_local_irq_restore+0x53/0x53 [ 44.545559] ? vprintk_default+0x28/0x30 [ 44.549584] ? __lock_acquire+0x3ff0/0x4620 [ 44.553872] panic+0x1e4/0x417 [ 44.557031] ? __warn+0x1d9/0x1d9 [ 44.560453] ? __lock_acquire+0x407b/0x4620 [ 44.564738] kasan_end_report+0x50/0x50 [ 44.568672] kasan_report+0x144/0x340 [ 44.572436] __asan_report_load8_noabort+0x14/0x20 [ 44.577326] __lock_acquire+0x407b/0x4620 [ 44.581436] ? unwind_dump+0x4c0/0x4c0 [ 44.585287] ? __kernel_text_address+0xd/0x40 [ 44.589742] ? unwind_get_return_address+0x61/0xa0 [ 44.594638] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 44.599790] ? __save_stack_trace+0x61/0xd0 [ 44.604084] ? get_signal+0x73f/0x16d0 [ 44.607934] ? save_stack_trace+0x16/0x20 [ 44.612045] ? __lock_acquire+0x20fd/0x4620 [ 44.616331] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 44.621573] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 44.626812] ? save_stack_trace+0x16/0x20 [ 44.630929] ? __lock_acquire+0x20fd/0x4620 [ 44.635212] ? osq_unlock+0x350/0x350 [ 44.638979] ? save_stack_trace+0x16/0x20 [ 44.643096] ? check_noncircular+0x20/0x20 [ 44.647294] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 44.652547] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 44.657711] ? __unwind_start+0x169/0x330 [ 44.661835] ? find_held_lock+0x39/0x1d0 [ 44.665873] ? lock_downgrade+0x990/0x990 [ 44.669992] ? check_noncircular+0x20/0x20 [ 44.674198] lock_acquire+0x1d5/0x580 [ 44.677965] ? exit_pi_state_list+0x369/0x7a0 [ 44.682433] ? lock_release+0xd70/0xd70 [ 44.686373] ? do_raw_spin_trylock+0x190/0x190 [ 44.690923] ? find_held_lock+0x39/0x1d0 [ 44.694956] _raw_spin_lock_irq+0x5e/0x80 [ 44.699076] ? exit_pi_state_list+0x369/0x7a0 [ 44.703539] exit_pi_state_list+0x369/0x7a0 [ 44.707828] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 44.713867] ? lock_release+0xd70/0xd70