[ 16.386267] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 20.158110] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 20.392247] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 21.212917] random: sshd: uninitialized urandom read (32 bytes read, 98 bits of entropy available) [ 21.381799] random: sshd: uninitialized urandom read (32 bytes read, 104 bits of entropy available) Warning: Permanently added '10.128.0.50' (ECDSA) to the list of known hosts. [ 26.775002] random: sshd: uninitialized urandom read (32 bytes read, 110 bits of entropy available) executing program [ 26.870314] ================================================================== [ 26.877711] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 26.884350] Read of size 8 at addr ffff8801d2e64ab8 by task syzkaller063830/3321 [ 26.891853] [ 26.893452] CPU: 0 PID: 3321 Comm: syzkaller063830 Not tainted 4.4.110-gdac1439 #13 [ 26.901208] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.910533] 0000000000000000 bf42c1480c842397 ffff8800b4967850 ffffffff81d04e3d [ 26.918485] ffffea00074b9900 ffff8801d2e64ab8 0000000000000000 ffff8801d2e64ab8 [ 26.926431] 0000000000000000 ffff8800b4967888 ffffffff814fd1f3 ffff8801d2e64ab8 [ 26.934403] Call Trace: [ 26.936966] [] dump_stack+0xc1/0x124 [ 26.942300] [] print_address_description+0x73/0x260 [ 26.948934] [] kasan_report+0x285/0x370 [ 26.954527] [] ? __lock_acquire+0x387e/0x4b50 [ 26.960638] [] __asan_report_load8_noabort+0x14/0x20 [ 26.967356] [] __lock_acquire+0x387e/0x4b50 [ 26.973295] [] ? __lock_acquire+0xb5f/0x4b50 [ 26.979320] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 26.986310] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 26.993121] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.000103] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.007080] [] lock_acquire+0x15e/0x460 [ 27.012675] [] ? remove_wait_queue+0x14/0x40 [ 27.018699] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 27.024981] [] ? remove_wait_queue+0x14/0x40 [ 27.031006] [] remove_wait_queue+0x14/0x40 [ 27.036858] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 27.043839] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 27.051081] [] ? ep_free+0x1c0/0x1c0 [ 27.056409] [] ep_free+0x93/0x1c0 [ 27.061476] [] ? ep_free+0x1c0/0x1c0 [ 27.066804] [] ep_eventpoll_release+0x44/0x60 [ 27.072922] [] __fput+0x233/0x6d0 [ 27.077995] [] ____fput+0x15/0x20 [ 27.083064] [] task_work_run+0x104/0x180 [ 27.088741] [] do_exit+0x871/0x2a20 [ 27.093984] [] ? handle_mm_fault+0x192d/0x3190 [ 27.100179] [] ? handle_mm_fault+0x3f2/0x3190 [ 27.106300] [] ? release_task+0x1240/0x1240 [ 27.112239] [] do_group_exit+0x108/0x320 [ 27.117918] [] SyS_exit_group+0x1d/0x20 [ 27.123509] [] ? do_group_exit+0x320/0x320 [ 27.129812] [] do_fast_syscall_32+0x314/0x890 [ 27.135925] [] sysenter_flags_fixed+0xd/0x17 [ 27.141947] [ 27.143542] Allocated by task 3321: [ 27.147131] [] save_stack_trace+0x26/0x50 [ 27.153009] [] save_stack+0x43/0xd0 [ 27.158365] [] kasan_kmalloc+0xad/0xe0 [ 27.163979] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 27.170548] [] binder_get_thread+0x181/0x7a0 [ 27.176690] [] binder_poll+0x4a/0x210 [ 27.182224] [] SyS_epoll_ctl+0x10b1/0x2050 [ 27.188191] [] do_fast_syscall_32+0x314/0x890 [ 27.194415] [] sysenter_flags_fixed+0xd/0x17 [ 27.200553] [ 27.202148] Freed by task 3321: [ 27.205389] [] save_stack_trace+0x26/0x50 [ 27.211267] [] save_stack+0x43/0xd0 [ 27.216626] [] kasan_slab_free+0x72/0xc0 [ 27.222412] [] kfree+0xfc/0x300 [ 27.227420] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 27.234166] [] binder_thread_release+0x27d/0x540 [ 27.240650] [] binder_ioctl+0xb94/0x12e0 [ 27.246440] [] compat_SyS_ioctl+0x28a/0x2540 [ 27.252580] [] do_fast_syscall_32+0x314/0x890 [ 27.258804] [] sysenter_flags_fixed+0xd/0x17 [ 27.264940] [ 27.266533] The buggy address belongs to the object at ffff8801d2e64a00 [ 27.266533] which belongs to the cache kmalloc-512 of size 512 [ 27.279167] The buggy address is located 184 bytes inside of [ 27.279167] 512-byte region [ffff8801d2e64a00, ffff8801d2e64c00) [ 27.291023] The buggy address belongs to the page: [ 27.297616] BUG: unable to handle kernel NULL pointer dereference at (null) [ 27.305846] IP: [< (null)>] (null) [ 27.311164] PGD 0 [ 27.313415] Oops: 0010 [#1] PREEMPT SMP KASAN [ 27.318406] Dumping ftrace buffer: [ 27.321936] (ftrace buffer empty) [ 27.325639] Modules linked in: [ 27.328949] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.110-gdac1439 #13 [ 27.335950] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.345304] task: ffff8801da3a17c0 task.stack: ffff8801da3b0000 [ 27.351355] RIP: 0010:[<0000000000000000>] [< (null)>] (null) [ 27.359113] RSP: 0018:ffff8801db307df0 EFLAGS: 00010006 [ 27.364556] RAX: ffff8801da3a17c0 RBX: ffff8800b428fdf8 RCX: ffffffff812ac8d0 [ 27.371817] RDX: 0000000000010000 RSI: ffffffff839fd820 RDI: ffff8800b428fdf8 [ 27.379082] RBP: ffff8801db307ee0 R08: 1ffff1003a9f2561 R09: 0000000000000001 [ 27.386347] R10: 0000000000000000 R11: 1ffff1003b660f6a R12: 0000000000000000 [ 27.393614] R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8801db319640 [ 27.400876] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 27.409110] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 27.414980] CR2: 0000000000000000 CR3: 00000001d0e2c000 CR4: 0000000000160670 [ 27.422248] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 27.429515] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 27.436784] Stack: [ 27.438929] ffffffff812ac8d6 ffff88021fffd057 ffff88021fffd05b ffff88021fffd04f [ 27.446960] 1ffff1003b660fcb ffff8801db3196a0 ffffed003b660fca ffff8801db319700 [ 27.454985] 0303fc0000000001 ffff8801db319678 ffffed003b6632d4 ffff8801db319718 [ 27.463026] Call Trace: [ 27.465591] [ 27.467653] [] ? __hrtimer_run_queues+0x306/0xfe0 [ 27.474450] [] ? hrtimer_fixup_init+0x70/0x70 [ 27.480596] [] ? hrtimer_interrupt+0x131/0x440 [ 27.486832] [] hrtimer_interrupt+0x1a6/0x440 [ 27.492892] [] local_apic_timer_interrupt+0x6a/0xb0 [ 27.499583] [] smp_apic_timer_interrupt+0x76/0xa0 [ 27.506092] [] apic_timer_interrupt+0xa0/0xb0 [ 27.512223] [ 27.514289] [] ? native_safe_halt+0x6/0x10 [ 27.520476] [] ? trace_hardirqs_on+0xd/0x10 [ 27.526454] [] default_idle+0x55/0x3c0 [ 27.531996] [] arch_cpu_idle+0xa/0x10 [ 27.537451] [] default_idle_call+0x48/0x70 [ 27.543332] [] cpu_startup_entry+0x605/0x820 [ 27.549394] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 27.556238] [] ? call_cpuidle+0xe0/0xe0 [ 27.561861] [] ? clockevents_register_device+0x122/0x230 [ 27.568955] [] start_secondary+0x304/0x3e0 [ 27.574847] [] ? set_cpu_sibling_map+0x1040/0x1040 [ 27.581414] Code: Bad RIP value. [ 27.585121] RIP [< (null)>] (null) [ 27.590517] RSP [ 27.594139] CR2: 0000000000000000 [ 27.597586] ---[ end trace 31fbd0b010930100 ]--- [ 27.602337] Kernel panic - not syncing: Fatal exception in interrupt [ 28.718575] Shutting down cpus with NMI [ 28.723401] Dumping ftrace buffer: [ 28.726922] (ftrace buffer empty) [ 28.730601] Kernel Offset: disabled [ 28.734193] Rebooting in 86400 seconds..