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-386-4,10.128.0.54' (ECDSA) to the list of known hosts. 2017/10/04 00:23:55 parsed 1 programs 2017/10/04 00:23:55 executed programs: 0 syzkaller login: [ 29.682215] ================================================================== [ 29.689614] BUG: KASAN: use-after-free in __lock_acquire+0x407b/0x4620 [ 29.696260] Read of size 8 at addr ffff8801c9fe26e8 by task syz-executor3/4395 [ 29.703590] [ 29.705202] CPU: 1 PID: 4395 Comm: syz-executor3 Not tainted 4.14.0-rc3+ #23 [ 29.712368] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.721701] Call Trace: [ 29.724263] dump_stack+0x194/0x257 [ 29.727874] ? arch_local_irq_restore+0x53/0x53 [ 29.732521] ? show_regs_print_info+0x65/0x65 [ 29.737000] ? __kernel_text_address+0xd/0x40 [ 29.741472] ? __lock_acquire+0x407b/0x4620 [ 29.745761] print_address_description+0x73/0x250 [ 29.750571] ? __lock_acquire+0x407b/0x4620 [ 29.754862] kasan_report+0x25b/0x340 [ 29.758637] __asan_report_load8_noabort+0x14/0x20 [ 29.763548] __lock_acquire+0x407b/0x4620 [ 29.767671] ? unwind_dump+0x4c0/0x4c0 [ 29.771532] ? __kernel_text_address+0xd/0x40 [ 29.776003] ? unwind_get_return_address+0x61/0xa0 [ 29.780913] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 29.786079] ? __save_stack_trace+0x61/0xd0 [ 29.790375] ? get_signal+0x73f/0x16d0 [ 29.794235] ? save_stack_trace+0x16/0x20 [ 29.798356] ? __lock_acquire+0x20fd/0x4620 [ 29.802657] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 29.807834] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 29.813013] ? save_stack_trace+0x16/0x20 [ 29.817146] ? __lock_acquire+0x20fd/0x4620 [ 29.821449] ? osq_unlock+0x350/0x350 [ 29.825225] ? save_stack_trace+0x16/0x20 [ 29.829360] ? check_noncircular+0x20/0x20 [ 29.833587] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 29.838754] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 29.843920] ? __unwind_start+0x169/0x330 [ 29.848039] ? find_held_lock+0x39/0x1d0 [ 29.852079] ? lock_downgrade+0x990/0x990 [ 29.856205] ? check_noncircular+0x20/0x20 [ 29.860423] lock_acquire+0x1d5/0x580 [ 29.864205] ? exit_pi_state_list+0x369/0x7a0 [ 29.868686] ? lock_release+0xd70/0xd70 [ 29.872638] ? do_raw_spin_trylock+0x190/0x190 [ 29.877192] ? find_held_lock+0x39/0x1d0 [ 29.881239] _raw_spin_lock_irq+0x5e/0x80 [ 29.885363] ? exit_pi_state_list+0x369/0x7a0 [ 29.889834] exit_pi_state_list+0x369/0x7a0 [ 29.894135] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 29.900173] ? lock_release+0xd70/0xd70 [ 29.904121] ? check_same_owner+0x320/0x320 [ 29.908418] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 29.913502] ? __might_sleep+0x95/0x190 [ 29.917458] ? __might_fault+0x188/0x1d0 [ 29.921502] ? do_raw_spin_trylock+0x190/0x190 [ 29.926064] mm_release+0x46d/0x590 [ 29.929662] ? do_raw_spin_trylock+0x190/0x190 [ 29.934214] ? mm_access+0x140/0x140 [ 29.937897] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.942361] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 29.947348] ? trace_hardirqs_on+0xd/0x10 [ 29.951474] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.955939] ? acct_collect+0x637/0x800 [ 29.959881] do_exit+0x481/0x1af0 [ 29.963301] ? mm_update_next_owner+0x930/0x930 [ 29.967935] ? lock_downgrade+0x990/0x990 [ 29.972048] ? refill_pi_state_cache.part.6+0x2f0/0x2f0 [ 29.977377] ? futex_wait+0x3ad/0x990 [ 29.981147] ? do_raw_spin_trylock+0x190/0x190 [ 29.985695] ? fault_in_user_writeable+0x90/0x90 [ 29.990418] ? futex_wake+0x680/0x680 [ 29.994185] ? check_noncircular+0x20/0x20 [ 29.998393] ? drop_futex_key_refs.isra.13+0x63/0xb0 [ 30.003464] ? futex_wait+0x69e/0x990 [ 30.007239] ? futex_wait_setup+0x3d0/0x3d0 [ 30.011537] ? find_held_lock+0x39/0x1d0 [ 30.015569] ? lock_downgrade+0x990/0x990 [ 30.019685] ? recalc_sigpending_tsk+0x117/0x150 [ 30.024407] ? recalc_sigpending+0x103/0x160 [ 30.028779] ? recalc_sigpending_tsk+0x150/0x150 [ 30.033500] ? get_signal+0x2b2/0x16d0 [ 30.037360] do_group_exit+0x149/0x400 [ 30.041216] ? __lock_is_held+0xbc/0x140 [ 30.045240] ? SyS_exit+0x30/0x30 [ 30.048673] ? _raw_spin_unlock_irq+0x27/0x70 [ 30.053134] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 30.058117] get_signal+0x73f/0x16d0 [ 30.061799] ? ptrace_notify+0x130/0x130 [ 30.065824] ? __schedule+0x8f3/0x2080 [ 30.069684] ? __sched_text_start+0x8/0x8 [ 30.073810] ? userfaultfd_unmap_complete+0x327/0x510 [ 30.078974] do_signal+0x94/0x1ee0 [ 30.082480] ? do_mmap+0x34f/0xd50 [ 30.085990] ? up_write+0x6b/0x120 [ 30.089501] ? setup_sigcontext+0x7d0/0x7d0 [ 30.093795] ? security_mmap_file+0x143/0x180 [ 30.098264] ? schedule+0xf5/0x430 [ 30.101768] ? vm_mmap_pgoff+0x13b/0x280 [ 30.105792] ? __schedule+0x2080/0x2080 [ 30.109729] ? vma_is_stack_for_current+0xa0/0xa0 [ 30.114537] ? find_held_lock+0x39/0x1d0 [ 30.118564] ? __compat_get_timespec+0xd9/0x120 [ 30.123211] ? exit_to_usermode_loop+0x8c/0x310 [ 30.127857] exit_to_usermode_loop+0x214/0x310 [ 30.132405] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 30.137910] ? lock_acquire+0x1d5/0x580 [ 30.141852] ? do_fast_syscall_32+0x158/0xf05 [ 30.146315] do_fast_syscall_32+0x83e/0xf05 [ 30.150602] ? compat_start_thread+0x80/0x80 [ 30.154980] ? do_int80_syscall_32+0x940/0x940 [ 30.159527] ? lockdep_sys_exit+0x47/0xf0 [ 30.163640] ? syscall_return_slowpath+0x2b3/0x510 [ 30.168534] ? finish_task_switch+0x1aa/0x740 [ 30.172997] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 30.177982] ? sysret32_from_system_call+0x5/0x3b [ 30.182792] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.187611] entry_SYSENTER_compat+0x51/0x60 [ 30.191994] RIP: 0023:0xf7fe6c79 [ 30.195332] RSP: 002b:00000000f7fe212c EFLAGS: 00000292 ORIG_RAX: 00000000000000f0 [ 30.203004] RAX: fffffffffffffe00 RBX: 0000000008128018 RCX: 0000000000000000 [ 30.210246] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 30.217478] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 30.224710] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 30.231944] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 30.239181] [ 30.240774] Allocated by task 4420: [ 30.244369] save_stack_trace+0x16/0x20 [ 30.248307] save_stack+0x43/0xd0 [ 30.251722] kasan_kmalloc+0xad/0xe0 [ 30.255398] kmem_cache_alloc_trace+0x136/0x750 [ 30.260031] refill_pi_state_cache.part.6+0xa5/0x2f0 [ 30.265096] futex_requeue+0x1887/0x2370 [ 30.269121] do_futex+0x7f5/0x20d0 [ 30.272622] compat_SyS_futex+0x27f/0x380 [ 30.276734] do_fast_syscall_32+0x3f2/0xf05 [ 30.281020] entry_SYSENTER_compat+0x51/0x60 [ 30.285389] [ 30.286980] Freed by task 4408: [ 30.290225] save_stack_trace+0x16/0x20 [ 30.294161] save_stack+0x43/0xd0 [ 30.297577] kasan_slab_free+0x71/0xc0 [ 30.301425] kfree+0xca/0x250 [ 30.304492] put_pi_state+0x3f4/0x560 [ 30.308252] unqueue_me_pi+0x4a/0xc0 [ 30.311930] futex_wait_requeue_pi.constprop.19+0xc7f/0x1300 [ 30.317694] do_futex+0x825/0x20d0 [ 30.321200] compat_SyS_futex+0x27f/0x380 [ 30.325314] do_fast_syscall_32+0x3f2/0xf05 [ 30.329610] entry_SYSENTER_compat+0x51/0x60 [ 30.333980] [ 30.335575] The buggy address belongs to the object at ffff8801c9fe26c0 [ 30.335575] which belongs to the cache kmalloc-256 of size 256 [ 30.348194] The buggy address is located 40 bytes inside of [ 30.348194] 256-byte region [ffff8801c9fe26c0, ffff8801c9fe27c0) [ 30.359946] The buggy address belongs to the page: [ 30.364840] page:ffffea000727f880 count:1 mapcount:0 mapping:ffff8801c9fe2080 index:0x0 [ 30.372943] flags: 0x200000000000100(slab) [ 30.377142] raw: 0200000000000100 ffff8801c9fe2080 0000000000000000 000000010000000c [ 30.384986] raw: ffffea000727f760 ffffea00072600a0 ffff8801dac007c0 0000000000000000 [ 30.392828] page dumped because: kasan: bad access detected [ 30.398498] [ 30.400088] Memory state around the buggy address: [ 30.404980] ffff8801c9fe2580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.412312] ffff8801c9fe2600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.419643] >ffff8801c9fe2680: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 30.426962] ^ [ 30.433676] ffff8801c9fe2700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.440999] ffff8801c9fe2780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 30.448345] ================================================================== [ 30.455664] Disabling lock debugging due to kernel taint [ 30.461075] Kernel panic - not syncing: panic_on_warn set ... [ 30.461075] [ 30.468401] CPU: 1 PID: 4395 Comm: syz-executor3 Tainted: G B 4.14.0-rc3+ #23 [ 30.476762] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.486080] Call Trace: [ 30.488642] dump_stack+0x194/0x257 [ 30.492242] ? arch_local_irq_restore+0x53/0x53 [ 30.496875] ? vprintk_default+0x28/0x30 [ 30.500903] ? __lock_acquire+0x3ff0/0x4620 [ 30.505188] panic+0x1e4/0x417 [ 30.508343] ? __warn+0x1d9/0x1d9 [ 30.511761] ? __lock_acquire+0x407b/0x4620 [ 30.516047] kasan_end_report+0x50/0x50 [ 30.519986] kasan_report+0x144/0x340 [ 30.523748] __asan_report_load8_noabort+0x14/0x20 [ 30.528642] __lock_acquire+0x407b/0x4620 [ 30.532751] ? unwind_dump+0x4c0/0x4c0 [ 30.536602] ? __kernel_text_address+0xd/0x40 [ 30.541061] ? unwind_get_return_address+0x61/0xa0 [ 30.545957] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 30.551110] ? __save_stack_trace+0x61/0xd0 [ 30.555394] ? get_signal+0x73f/0x16d0 [ 30.559244] ? save_stack_trace+0x16/0x20 [ 30.563356] ? __lock_acquire+0x20fd/0x4620 [ 30.567642] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 30.572796] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 30.577948] ? save_stack_trace+0x16/0x20 [ 30.582058] ? __lock_acquire+0x20fd/0x4620 [ 30.586341] ? osq_unlock+0x350/0x350 [ 30.590102] ? save_stack_trace+0x16/0x20 [ 30.594215] ? check_noncircular+0x20/0x20 [ 30.598413] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 30.603568] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 30.608719] ? __unwind_start+0x169/0x330 [ 30.612834] ? find_held_lock+0x39/0x1d0 [ 30.616860] ? lock_downgrade+0x990/0x990 [ 30.620970] ? check_noncircular+0x20/0x20 [ 30.625167] lock_acquire+0x1d5/0x580 [ 30.628930] ? exit_pi_state_list+0x369/0x7a0 [ 30.633388] ? lock_release+0xd70/0xd70 [ 30.637323] ? do_raw_spin_trylock+0x190/0x190 [ 30.641866] ? find_held_lock+0x39/0x1d0 [ 30.645894] _raw_spin_lock_irq+0x5e/0x80 [ 30.650004] ? exit_pi_state_list+0x369/0x7a0 [ 30.654466] exit_pi_state_list+0x369/0x7a0 [ 30.658753] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 30.664773] ? lock_release+0xd70/0xd70 [ 30.668712] ? check_same_owner+0x320/0x320 [ 30.672998] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 30.678069] ? __might_sleep+0x95/0x190 [ 30.682011] ? __might_fault+0x188/0x1d0