[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 18.819818] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 23.239938] random: sshd: uninitialized urandom read (32 bytes read) [ 23.602592] random: sshd: uninitialized urandom read (32 bytes read) [ 24.376265] random: sshd: uninitialized urandom read (32 bytes read) [ 24.566296] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.41' (ECDSA) to the list of known hosts. [ 30.066267] random: sshd: uninitialized urandom read (32 bytes read) 2018/05/08 03:35:44 parsed 1 programs 2018/05/08 03:35:44 executed programs: 0 [ 30.573793] IPVS: ftp: loaded support on port[0] = 21 [ 30.584858] IPVS: ftp: loaded support on port[0] = 21 [ 30.605857] IPVS: ftp: loaded support on port[0] = 21 [ 30.610491] IPVS: ftp: loaded support on port[0] = 21 [ 30.661983] IPVS: ftp: loaded support on port[0] = 21 [ 30.668218] IPVS: ftp: loaded support on port[0] = 21 [ 30.732283] IPVS: ftp: loaded support on port[0] = 21 [ 30.754931] IPVS: ftp: loaded support on port[0] = 21 [ 32.723789] ================================================================== [ 32.731352] BUG: KASAN: use-after-free in irq_bypass_register_consumer+0x4b1/0x530 [ 32.739074] Read of size 8 at addr ffff8801b7f07738 by task syz-executor1/4951 [ 32.746433] [ 32.748075] CPU: 0 PID: 4951 Comm: syz-executor1 Not tainted 4.17.0-rc4+ #62 [ 32.755260] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 32.764612] Call Trace: [ 32.767213] dump_stack+0x1b9/0x294 [ 32.770857] ? dump_stack_print_info.cold.2+0x52/0x52 [ 32.776060] ? printk+0x9e/0xba [ 32.779356] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 32.784127] ? kasan_check_write+0x14/0x20 [ 32.788378] print_address_description+0x6c/0x20b [ 32.793238] ? irq_bypass_register_consumer+0x4b1/0x530 [ 32.798617] kasan_report.cold.7+0x242/0x2fe [ 32.803049] __asan_report_load8_noabort+0x14/0x20 [ 32.807993] irq_bypass_register_consumer+0x4b1/0x530 [ 32.813200] ? __disconnect+0x1b0/0x1b0 [ 32.817194] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 32.822745] kvm_irqfd+0x1599/0x1ec0 [ 32.826472] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 32.832021] ? futex_wait_queue_me+0x550/0x820 [ 32.836625] ? kvm_eventfd_init+0x2a0/0x2a0 [ 32.840961] ? print_usage_bug+0xc0/0xc0 [ 32.845037] ? futex_wait_setup+0x279/0x400 [ 32.849395] ? lock_downgrade+0x8e0/0x8e0 [ 32.853648] ? lock_release+0xa10/0xa10 [ 32.857636] ? check_same_owner+0x320/0x320 [ 32.861978] ? __might_sleep+0x95/0x190 [ 32.865973] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 32.871530] ? _copy_from_user+0xdf/0x150 [ 32.875706] kvm_vm_ioctl+0xf84/0x1d90 [ 32.879627] ? kvm_set_memory_region+0x50/0x50 [ 32.884228] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 32.889434] ? do_futex+0x249/0x27d0 [ 32.893160] ? graph_lock+0x170/0x170 [ 32.896980] ? exit_robust_list+0x290/0x290 [ 32.901311] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 32.906374] ? find_held_lock+0x36/0x1c0 [ 32.910458] ? lock_downgrade+0x8e0/0x8e0 [ 32.914630] ? kasan_check_read+0x11/0x20 [ 32.918792] ? rcu_is_watching+0x85/0x140 [ 32.922960] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 32.928171] ? __fget+0x40c/0x650 [ 32.931652] ? bpf_raw_tracepoint_open.isra.29+0x1a1/0x820 [ 32.937297] ? expand_files.part.8+0x9a0/0x9a0 [ 32.941896] ? bpf_prog_get_type_dev+0x460/0x460 [ 32.946677] ? lock_downgrade+0x8e0/0x8e0 [ 32.950842] ? lock_release+0xa10/0xa10 [ 32.954830] ? check_same_owner+0x320/0x320 [ 32.959170] ? __check_object_size+0x95/0x5d9 [ 32.963694] ? __fget_light+0x2ef/0x430 [ 32.967698] kvm_vm_compat_ioctl+0x13b/0x420 [ 32.972123] ? kvm_vm_ioctl+0x1d90/0x1d90 [ 32.976282] ? __ia32_compat_sys_futex+0x3de/0x5e0 [ 32.981228] ? __x32_compat_sys_get_robust_list+0x430/0x430 [ 32.986960] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 32.992163] ? kvm_vm_ioctl+0x1d90/0x1d90 [ 32.996328] __ia32_compat_sys_ioctl+0x221/0x640 [ 33.001102] do_fast_syscall_32+0x345/0xf9b [ 33.005441] ? do_int80_syscall_32+0x880/0x880 [ 33.010035] ? _raw_spin_unlock_irq+0x27/0x70 [ 33.014546] ? finish_task_switch+0x1ca/0x810 [ 33.019059] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 33.024612] ? syscall_return_slowpath+0x30f/0x5c0 [ 33.029561] ? sysret32_from_system_call+0x5/0x46 [ 33.034425] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 33.039289] entry_SYSENTER_compat+0x70/0x7f [ 33.043703] RIP: 0023:0xf7f7bcb9 [ 33.047068] RSP: 002b:00000000f7f560ac EFLAGS: 00000282 ORIG_RAX: 0000000000000036 [ 33.054784] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000004020ae76 [ 33.062060] RDX: 0000000020018000 RSI: 0000000000000000 RDI: 0000000000000000 [ 33.069343] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 33.076622] R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 [ 33.083908] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 33.091207] [ 33.092835] Allocated by task 4951: [ 33.096472] save_stack+0x43/0xd0 [ 33.099941] kasan_kmalloc+0xc4/0xe0 [ 33.103667] kmem_cache_alloc_trace+0x152/0x780 [ 33.108344] kvm_irqfd+0x187/0x1ec0 [ 33.111977] kvm_vm_ioctl+0xf84/0x1d90 [ 33.115874] kvm_vm_compat_ioctl+0x13b/0x420 [ 33.120297] __ia32_compat_sys_ioctl+0x221/0x640 [ 33.125061] do_fast_syscall_32+0x345/0xf9b [ 33.129393] entry_SYSENTER_compat+0x70/0x7f [ 33.133800] [ 33.135429] Freed by task 4: [ 33.138456] save_stack+0x43/0xd0 [ 33.141939] __kasan_slab_free+0x11a/0x170 [ 33.146183] kasan_slab_free+0xe/0x10 [ 33.149986] kfree+0xd9/0x260 [ 33.153096] irqfd_shutdown+0x13a/0x1a0 [ 33.157074] process_one_work+0xc1e/0x1b50 [ 33.161313] worker_thread+0x1cc/0x1440 [ 33.165292] kthread+0x345/0x410 [ 33.168661] ret_from_fork+0x3a/0x50 [ 33.172367] [ 33.174000] The buggy address belongs to the object at ffff8801b7f075c0 [ 33.174000] which belongs to the cache kmalloc-512 of size 512 [ 33.186664] The buggy address is located 376 bytes inside of [ 33.186664] 512-byte region [ffff8801b7f075c0, ffff8801b7f077c0) [ 33.198539] The buggy address belongs to the page: [ 33.203479] page:ffffea0006dfc1c0 count:1 mapcount:0 mapping:ffff8801b7f070c0 index:0x0 [ 33.211634] flags: 0x2fffc0000000100(slab) [ 33.215892] raw: 02fffc0000000100 ffff8801b7f070c0 0000000000000000 0000000100000006 [ 33.223785] raw: ffffea0006dfc0e0 ffffea0006da7160 ffff8801da800940 0000000000000000 [ 33.231670] page dumped because: kasan: bad access detected [ 33.237382] [ 33.239009] Memory state around the buggy address: [ 33.243943] ffff8801b7f07600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.251309] ffff8801b7f07680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.258676] >ffff8801b7f07700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.266034] ^ [ 33.271234] ffff8801b7f07780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 33.278600] ffff8801b7f07800: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 33.285962] ================================================================== [ 33.293326] Disabling lock debugging due to kernel taint [ 33.298956] Kernel panic - not syncing: panic_on_warn set ... [ 33.298956] [ 33.306339] CPU: 0 PID: 4951 Comm: syz-executor1 Tainted: G B 4.17.0-rc4+ #62 [ 33.314915] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.324262] Call Trace: [ 33.326838] dump_stack+0x1b9/0x294 [ 33.330455] ? dump_stack_print_info.cold.2+0x52/0x52 [ 33.335634] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 33.340381] ? irq_bypass_register_consumer+0x450/0x530 [ 33.345731] panic+0x22f/0x4de [ 33.348919] ? add_taint.cold.5+0x16/0x16 [ 33.353069] ? do_raw_spin_unlock+0x9e/0x2e0 [ 33.357472] ? do_raw_spin_unlock+0x9e/0x2e0 [ 33.361870] ? irq_bypass_register_consumer+0x4b1/0x530 [ 33.367219] kasan_end_report+0x47/0x4f [ 33.371198] kasan_report.cold.7+0x76/0x2fe [ 33.375535] __asan_report_load8_noabort+0x14/0x20 [ 33.380462] irq_bypass_register_consumer+0x4b1/0x530 [ 33.385647] ? __disconnect+0x1b0/0x1b0 [ 33.389613] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 33.395319] kvm_irqfd+0x1599/0x1ec0 [ 33.399030] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 33.404558] ? futex_wait_queue_me+0x550/0x820 [ 33.409135] ? kvm_eventfd_init+0x2a0/0x2a0 [ 33.413440] ? print_usage_bug+0xc0/0xc0 [ 33.417489] ? futex_wait_setup+0x279/0x400 [ 33.421818] ? lock_downgrade+0x8e0/0x8e0 [ 33.425962] ? lock_release+0xa10/0xa10 [ 33.429932] ? check_same_owner+0x320/0x320 [ 33.434246] ? __might_sleep+0x95/0x190 [ 33.438214] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 33.443748] ? _copy_from_user+0xdf/0x150 [ 33.447903] kvm_vm_ioctl+0xf84/0x1d90 [ 33.451793] ? kvm_set_memory_region+0x50/0x50 [ 33.456379] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 33.461560] ? do_futex+0x249/0x27d0 [ 33.465260] ? graph_lock+0x170/0x170 [ 33.469054] ? exit_robust_list+0x290/0x290 [ 33.473358] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 33.478355] ? find_held_lock+0x36/0x1c0 [ 33.482412] ? lock_downgrade+0x8e0/0x8e0 [ 33.486550] ? kasan_check_read+0x11/0x20 [ 33.490691] ? rcu_is_watching+0x85/0x140 [ 33.494836] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 33.500048] ? __fget+0x40c/0x650 [ 33.503491] ? bpf_raw_tracepoint_open.isra.29+0x1a1/0x820 [ 33.509112] ? expand_files.part.8+0x9a0/0x9a0 [ 33.513696] ? bpf_prog_get_type_dev+0x460/0x460 [ 33.518448] ? lock_downgrade+0x8e0/0x8e0 [ 33.522579] ? lock_release+0xa10/0xa10 [ 33.526627] ? check_same_owner+0x320/0x320 [ 33.530934] ? __check_object_size+0x95/0x5d9 [ 33.535417] ? __fget_light+0x2ef/0x430 [ 33.539383] kvm_vm_compat_ioctl+0x13b/0x420 [ 33.543780] ? kvm_vm_ioctl+0x1d90/0x1d90 [ 33.547919] ? __ia32_compat_sys_futex+0x3de/0x5e0 [ 33.552838] ? __x32_compat_sys_get_robust_list+0x430/0x430 [ 33.558554] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 33.563738] ? kvm_vm_ioctl+0x1d90/0x1d90 [ 33.567876] __ia32_compat_sys_ioctl+0x221/0x640 [ 33.572621] do_fast_syscall_32+0x345/0xf9b [ 33.576927] ? do_int80_syscall_32+0x880/0x880 [ 33.581491] ? _raw_spin_unlock_irq+0x27/0x70 [ 33.585975] ? finish_task_switch+0x1ca/0x810 [ 33.590475] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 33.596026] ? syscall_return_slowpath+0x30f/0x5c0 [ 33.600952] ? sysret32_from_system_call+0x5/0x46 [ 33.605794] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 33.610623] entry_SYSENTER_compat+0x70/0x7f [ 33.615015] RIP: 0023:0xf7f7bcb9 [ 33.618367] RSP: 002b:00000000f7f560ac EFLAGS: 00000282 ORIG_RAX: 0000000000000036 [ 33.626059] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000004020ae76 [ 33.633313] RDX: 0000000020018000 RSI: 0000000000000000 RDI: 0000000000000000 [ 33.640567] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 33.647821] R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 [ 33.655084] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 33.662815] Dumping ftrace buffer: [ 33.666354] (ftrace buffer empty) [ 33.670042] Kernel Offset: disabled [ 33.673646] Rebooting in 86400 seconds..