[....] Starting OpenBSD Secure Shell server: sshd[ 16.261393] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.798871] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 22.097033] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 23.109222] random: sshd: uninitialized urandom read (32 bytes read, 122 bits of entropy available) [ 23.282942] random: sshd: uninitialized urandom read (32 bytes read, 127 bits of entropy available) [ 23.388060] random: nonblocking pool is initialized Warning: Permanently added '10.128.15.238' (ECDSA) to the list of known hosts. executing program [ 28.782316] ================================================================== [ 28.789818] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 28.796454] Read of size 8 at addr ffff8801d14a6fb8 by task syzkaller419575/3317 [ 28.803958] [ 28.805558] CPU: 1 PID: 3317 Comm: syzkaller419575 Not tainted 4.4.112-g52c02cf #23 [ 28.813321] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.822647] 0000000000000000 d2f030d6ae8dcdc0 ffff8800b43d7850 ffffffff81d056fd [ 28.830644] ffffea0007452980 ffff8801d14a6fb8 0000000000000000 ffff8801d14a6fb8 [ 28.838617] 0000000000000000 ffff8800b43d7888 ffffffff814fd953 ffff8801d14a6fb8 [ 28.846593] Call Trace: [ 28.849156] [] dump_stack+0xc1/0x124 [ 28.854492] [] print_address_description+0x73/0x260 [ 28.861135] [] kasan_report+0x285/0x370 [ 28.866742] [] ? __lock_acquire+0x387e/0x4b50 [ 28.872857] [] __asan_report_load8_noabort+0x14/0x20 [ 28.879577] [] __lock_acquire+0x387e/0x4b50 [ 28.885516] [] ? __lock_acquire+0xb5f/0x4b50 [ 28.891541] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.898525] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 28.905332] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.912318] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.919298] [] lock_acquire+0x15e/0x460 [ 28.924907] [] ? remove_wait_queue+0x14/0x40 [ 28.930938] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 28.937226] [] ? remove_wait_queue+0x14/0x40 [ 28.943259] [] remove_wait_queue+0x14/0x40 [ 28.949129] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 28.956114] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 28.963370] [] ? ep_free+0x1c0/0x1c0 [ 28.968701] [] ep_free+0x93/0x1c0 [ 28.973773] [] ? ep_free+0x1c0/0x1c0 [ 28.979118] [] ep_eventpoll_release+0x44/0x60 [ 28.985233] [] __fput+0x233/0x6d0 [ 28.990316] [] ____fput+0x15/0x20 [ 28.995388] [] task_work_run+0x104/0x180 [ 29.001074] [] do_exit+0x871/0x2a20 [ 29.006321] [] ? handle_mm_fault+0x192d/0x3190 [ 29.012521] [] ? handle_mm_fault+0x3f2/0x3190 [ 29.018635] [] ? release_task+0x1240/0x1240 [ 29.024579] [] do_group_exit+0x108/0x320 [ 29.030260] [] SyS_exit_group+0x1d/0x20 [ 29.035852] [] ? do_group_exit+0x320/0x320 [ 29.041707] [] do_fast_syscall_32+0x314/0x890 [ 29.047831] [] sysenter_flags_fixed+0xd/0x17 [ 29.053866] [ 29.055464] Allocated by task 3317: [ 29.059066] [] save_stack_trace+0x26/0x50 [ 29.064953] [] save_stack+0x43/0xd0 [ 29.070344] [] kasan_kmalloc+0xad/0xe0 [ 29.075987] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 29.082578] [] binder_get_thread+0x181/0x7a0 [ 29.088725] [] binder_poll+0x4a/0x210 [ 29.094261] [] SyS_epoll_ctl+0x10b1/0x2050 [ 29.100236] [] do_fast_syscall_32+0x314/0x890 [ 29.106784] [] sysenter_flags_fixed+0xd/0x17 [ 29.112936] [ 29.114532] Freed by task 3317: [ 29.117786] [] save_stack_trace+0x26/0x50 [ 29.123685] [] save_stack+0x43/0xd0 [ 29.129056] [] kasan_slab_free+0x72/0xc0 [ 29.134852] [] kfree+0xfc/0x300 [ 29.139865] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 29.146617] [] binder_thread_release+0x27d/0x540 [ 29.153108] [] binder_ioctl+0xb94/0x12e0 [ 29.158905] [] compat_SyS_ioctl+0x28a/0x2540 [ 29.165048] [] do_fast_syscall_32+0x314/0x890 [ 29.171281] [] sysenter_flags_fixed+0xd/0x17 [ 29.177425] [ 29.179024] The buggy address belongs to the object at ffff8801d14a6f00 [ 29.179024] which belongs to the cache kmalloc-512 of size 512 [ 29.191647] The buggy address is located 184 bytes inside of [ 29.191647] 512-byte region [ffff8801d14a6f00, ffff8801d14a7100) [ 29.203490] The buggy address belongs to the page: [ 29.237426] kasan: CONFIG_KASAN_INLINE enabled [ 29.241878] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN [ 29.254841] Dumping ftrace buffer: [ 29.258374] (ftrace buffer empty) [ 29.262081] Modules linked in: [ 29.265398] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.112-g52c02cf #23 [ 29.273338] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.282688] task: ffffffff84217840 task.stack: ffffffff84200000 [ 29.288744] RIP: 0010:[] [] debug_object_deactivate+0x1a6/0x3c0 [ 29.298159] RSP: 0018:ffff8801db207d10 EFLAGS: 00010007 [ 29.303597] RAX: 0000000000000096 RBX: 00000000fff5751c RCX: ffff8801da38fb30 [ 29.310856] RDX: 000000001ffeaea6 RSI: ffffffff842c2560 RDI: 00000000fff57534 [ 29.318126] RBP: ffff8801db207dd8 R08: 1ffff100164d7f99 R09: ffffffff85133d90 [ 29.325393] R10: 0000000000000001 R11: 1ffff1003b640f68 R12: 1ffff1003b640fa6 [ 29.332660] R13: 0000000000074602 R14: dffffc0000000000 R15: ffffffff8585b808 [ 29.339934] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 29.348149] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 29.354025] CR2: 0000560f5443d110 CR3: 00000001d15fa000 CR4: 0000000000160670 [ 29.361298] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.368564] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.375829] Stack: [ 29.377970] 0000000000000000 ffffffff842c2560 ffff8801da38fb30 0000000000000096 [ 29.386034] 0000000041b58ab3 ffffffff83fccfc9 ffffffff81d67510 ffffffff812a1a42 [ 29.394085] ffffffff00000000 ffff880100000000 0000000000000046 ffffffff84217840 [ 29.402137] Call Trace: [ 29.404708] [ 29.406769] [] ? debug_object_activate+0x500/0x500 [ 29.413651] [] ? run_timer_softirq+0x102/0xbb0 [ 29.419879] [] ? init_timer_key+0x360/0x360 [ 29.425849] [] run_timer_softirq+0x336/0xbb0 [ 29.431952] [] ? clockevents_program_event+0x1a5/0x350 [ 29.438874] [] ? msleep+0xe0/0xe0 [ 29.443977] [] __do_softirq+0x24d/0xa59 [ 29.449594] [] irq_exit+0x119/0x140 [ 29.454875] [] smp_apic_timer_interrupt+0x7b/0xa0 [ 29.461369] [] apic_timer_interrupt+0xa0/0xb0 [ 29.467503] [ 29.469569] [] ? native_safe_halt+0x6/0x10 [ 29.475753] [] default_idle+0x55/0x3c0 [ 29.481284] [] arch_cpu_idle+0xa/0x10 [ 29.486733] [] default_idle_call+0x48/0x70 [ 29.492613] [] cpu_startup_entry+0x605/0x820 [ 29.498665] [] ? call_cpuidle+0xe0/0xe0 [ 29.504285] [] rest_init+0x189/0x190 [ 29.509640] [] start_kernel+0x6b9/0x6ee [ 29.515265] [] ? thread_stack_cache_init+0xb/0xb [ 29.521664] [] ? early_idt_handler_array+0x120/0x120 [ 29.528676] [] ? early_idt_handler_array+0x120/0x120 [ 29.535428] [] x86_64_start_reservations+0x2a/0x2c [ 29.542014] [] x86_64_start_kernel+0x140/0x163 [ 29.548231] Code: eb 1a 48 89 da 48 c1 ea 03 42 80 3c 32 00 0f 85 86 01 00 00 48 8b 1b 48 85 db 74 7a 48 8d 7b 18 41 83 c5 01 48 89 fa 48 c1 ea 03 <42> 80 3c 32 00 0f 85 3c 01 00 00 48 3b 4b 18 75 c6 48 8d 7b 10 [ 29.575851] RIP [] debug_object_deactivate+0x1a6/0x3c0 [ 29.582916] RSP [ 29.586537] ---[ end trace a99f7dae2f3ec87d ]--- [ 29.591283] Kernel panic - not syncing: Fatal exception in interrupt [ 30.716038] Shutting down cpus with NMI [ 30.721051] Dumping ftrace buffer: [ 30.724572] (ftrace buffer empty) [ 30.728251] Kernel Offset: disabled [ 30.731846] Rebooting in 86400 seconds..