[ 16.072108] random: sshd: uninitialized urandom read (32 bytes read, 33 bits of entropy available) [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 19.928873] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 20.172808] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 21.099558] random: sshd: uninitialized urandom read (32 bytes read, 111 bits of entropy available) [ 31.910320] random: sshd: uninitialized urandom read (32 bytes read, 120 bits of entropy available) Warning: Permanently added '10.128.15.194' (ECDSA) to the list of known hosts. [ 37.277023] random: sshd: uninitialized urandom read (32 bytes read, 126 bits of entropy available) executing program [ 37.372294] ================================================================== [ 37.379803] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 37.386443] Read of size 8 at addr ffff8801d0094338 by task syzkaller118310/3331 [ 37.393946] [ 37.395548] CPU: 1 PID: 3331 Comm: syzkaller118310 Not tainted 4.4.113-ge70c132 #34 [ 37.403313] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 37.413343] 0000000000000000 655a4864b4102bac ffff8801d0f5f8f0 ffffffff81d0278d [ 37.421317] ffffea0007402500 ffff8801d0094338 0000000000000000 ffff8801d0094338 [ 37.429306] 0000000000000000 ffff8801d0f5f928 ffffffff814fd053 ffff8801d0094338 [ 37.437288] Call Trace: [ 37.439850] [] dump_stack+0xc1/0x124 [ 37.445188] [] print_address_description+0x73/0x260 [ 37.451826] [] kasan_report+0x285/0x370 [ 37.457432] [] ? __lock_acquire+0x387e/0x4b50 [ 37.463549] [] __asan_report_load8_noabort+0x14/0x20 [ 37.470281] [] __lock_acquire+0x387e/0x4b50 [ 37.476222] [] ? __lock_acquire+0xb5f/0x4b50 [ 37.482264] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 37.489250] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 37.496235] [] ? mark_held_locks+0xaf/0x100 [ 37.502183] [] lock_acquire+0x15e/0x460 [ 37.507791] [] ? remove_wait_queue+0x14/0x40 [ 37.513823] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 37.520110] [] ? remove_wait_queue+0x14/0x40 [ 37.526149] [] remove_wait_queue+0x14/0x40 [ 37.532006] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 37.538991] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 37.546254] [] ? ep_free+0x1c0/0x1c0 [ 37.551590] [] ep_free+0x93/0x1c0 [ 37.556665] [] ? ep_free+0x1c0/0x1c0 [ 37.562015] [] ep_eventpoll_release+0x44/0x60 [ 37.568132] [] __fput+0x233/0x6d0 [ 37.573207] [] ____fput+0x15/0x20 [ 37.578295] [] task_work_run+0x104/0x180 [ 37.583978] [] do_exit+0x82a/0x2a10 [ 37.589226] [] ? binder_ioctl_write_read.isra.55+0xbc0/0xbc0 [ 37.596645] [] ? release_task+0x1240/0x1240 [ 37.602588] [] ? SyS_epoll_create+0x190/0x190 [ 37.608705] [] do_group_exit+0x108/0x320 [ 37.614385] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 37.620847] [] SyS_exit_group+0x1d/0x20 [ 37.626451] [] entry_SYSCALL_64_fastpath+0x1c/0x98 [ 37.632998] [ 37.634599] Allocated by task 3331: [ 37.638206] [] save_stack_trace+0x26/0x50 [ 37.644093] [] save_stack+0x43/0xd0 [ 37.649460] [] kasan_kmalloc+0xad/0xe0 [ 37.655085] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 37.661684] [] binder_get_thread+0x15d/0x750 [ 37.667829] [] binder_poll+0x4a/0x210 [ 37.673368] [] SyS_epoll_ctl+0x10b1/0x2040 [ 37.679365] [] entry_SYSCALL_64_fastpath+0x1c/0x98 [ 37.686044] [ 37.687642] Freed by task 3331: [ 37.690887] [] save_stack_trace+0x26/0x50 [ 37.696775] [] save_stack+0x43/0xd0 [ 37.702138] [] kasan_slab_free+0x72/0xc0 [ 37.707936] [] kfree+0xfc/0x300 [ 37.712968] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 37.719731] [] binder_thread_release+0x27d/0x540 [ 37.726235] [] binder_ioctl+0xb94/0x12e0 [ 37.732036] [] do_vfs_ioctl+0x7aa/0xee0 [ 37.737752] [] SyS_ioctl+0x8f/0xc0 [ 37.743032] [] entry_SYSCALL_64_fastpath+0x1c/0x98 [ 37.749697] [ 37.751306] The buggy address belongs to the object at ffff8801d0094280 [ 37.751306] which belongs to the cache kmalloc-512 of size 512 [ 37.763935] The buggy address is located 184 bytes inside of [ 37.763935] 512-byte region [ffff8801d0094280, ffff8801d0094480) [ 37.775779] The buggy address belongs to the page: [ 37.966873] kasan: CONFIG_KASAN_INLINE enabled [ 37.971311] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN [ 37.984125] Dumping ftrace buffer: [ 37.987633] (ftrace buffer empty) [ 37.991312] Modules linked in: [ 37.994590] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.113-ge70c132 #34 [ 38.001568] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.010894] task: ffffffff84217840 task.stack: ffffffff84200000 [ 38.016919] RIP: 0010:[] [] rb_insert_color+0x9f/0xcb0 [ 38.025496] RSP: 0018:ffff8801db207d18 EFLAGS: 00010003 [ 38.030912] RAX: 0a0508a8e82a0be9 RBX: ffffffff838a8de0 RCX: ffffffff838a8de0 [ 38.038150] RDX: 1ffffffff07151bd RSI: ffff8801db219710 RDI: ffff8801db219e80 [ 38.045389] RBP: ffff8801db207d60 R08: ffffffff8580af08 R09: 0000000000000001 [ 38.052632] R10: 0000000000000000 R11: 1ffff1003b640f62 R12: ffff8801d06a7df8 [ 38.059884] R13: 5028454741505f4e R14: ffff8801db219e80 R15: dffffc0000000000 [ 38.067124] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 38.075317] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 38.081167] CR2: 000055a461e70110 CR3: 00000001d1364000 CR4: 0000000000160670 [ 38.088410] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 38.095653] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 38.102892] Stack: [ 38.105010] ffffffff842bdb20 ffffffff842180b0 0000000000000000 ffff8801db207d70 [ 38.112980] ffff8801db219e80 dffffc0000000000 0000000000000000 ffff8801db219710 [ 38.120950] ffff8801d06a7e00 ffff8801db207db0 ffffffff81d20067 ffff8801db219e98 [ 38.128918] Call Trace: [ 38.131468] [ 38.133504] [] timerqueue_add+0x157/0x2a0 [ 38.139561] [] enqueue_hrtimer+0x168/0x450 [ 38.145415] [] __hrtimer_run_queues+0x732/0xfe0 [ 38.151704] [] ? hrtimer_fixup_init+0x70/0x70 [ 38.157831] [] ? hrtimer_interrupt+0x131/0x440 [ 38.164029] [] hrtimer_interrupt+0x1a6/0x440 [ 38.170057] [] local_apic_timer_interrupt+0x6a/0xb0 [ 38.176696] [] smp_apic_timer_interrupt+0x76/0xa0 [ 38.183158] [] apic_timer_interrupt+0xa0/0xb0 [ 38.189278] [ 38.191313] [] ? native_safe_halt+0x6/0x10 [ 38.197455] [] default_idle+0x55/0x3c0 [ 38.202960] [] arch_cpu_idle+0xa/0x10 [ 38.208392] [] default_idle_call+0x48/0x70 [ 38.214245] [] cpu_startup_entry+0x5fd/0x8f0 [ 38.220281] [] ? _raw_spin_unlock_irqrestore+0x5a/0x70 [ 38.227175] [] ? call_cpuidle+0xe0/0xe0 [ 38.232768] [] rest_init+0x189/0x190 [ 38.238101] [] start_kernel+0x6b9/0x6ee [ 38.243697] [] ? thread_stack_cache_init+0xb/0xb [ 38.250072] [] ? early_idt_handler_array+0x120/0x120 [ 38.256793] [] ? early_idt_handler_array+0x120/0x120 [ 38.263514] [] x86_64_start_reservations+0x2a/0x2c [ 38.270064] [] x86_64_start_kernel+0x140/0x163 [ 38.276263] Code: 48 89 c2 48 c1 ea 03 42 80 3c 3a 00 0f 85 94 09 00 00 4c 8b 6b 08 4d 39 e5 0f 84 b0 01 00 00 4d 85 ed 74 1d 4c 89 e8 48 c1 e8 03 <42> 80 3c 38 00 0f 85 95 09 00 00 41 f6 45 00 01 0f 84 20 03 00 [ 38.302863] RIP [] rb_insert_color+0x9f/0xcb0 [ 38.309095] RSP [ 38.312696] ---[ end trace 2d77f0e8995d3713 ]--- [ 38.317421] Kernel panic - not syncing: Fatal exception in interrupt [ 39.322756] PANIC: double fault, error_code: 0x0 [ 39.327551] CPU: 1 PID: 3331 Comm: syzkaller118310 Tainted: G D 4.4.113-ge70c132 #34 [ 39.336531] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 39.345854] task: ffff8801d18f4740 task.stack: ffff8801d0f58000 [ 39.351916] RIP: 0010:[] [] dump_page_badflags+0x8/0x250 [ 39.360714] RSP: 0018:ffff880100000000 EFLAGS: 00010046 [ 39.366133] RAX: ffff8801d18f4740 RBX: ffffea0007402500 RCX: ffffffff8148f8d0 [ 39.373371] RDX: 0000000000000000 RSI: ffffffff838a8de0 RDI: ffffea0007402500 [ 39.380612] RBP: ffff880100000010 R08: 0000000000000001 R09: 0000000000000000