[ 15.985925] random: sshd: uninitialized urandom read (32 bytes read, 32 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: [ 22.240989] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 22.465908] random: sshd: uninitialized urandom read (32 bytes read, 40 bits of entropy available) [ 23.380304] random: sshd: uninitialized urandom read (32 bytes read, 118 bits of entropy available) [ 36.970666] random: nonblocking pool is initialized Warning: Permanently added '10.128.0.23' (ECDSA) to the list of known hosts. executing program [ 42.413874] ================================================================== [ 42.421295] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 42.428625] Read of size 8 at addr ffff8801d131cd38 by task syzkaller380159/3325 [ 42.436125] [ 42.437727] CPU: 1 PID: 3325 Comm: syzkaller380159 Not tainted 4.4.112-gd96d95d #24 [ 42.445486] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.454809] 0000000000000000 b854057f7361dd98 ffff8801d0727850 ffffffff81d054ed [ 42.462781] ffffea000744c700 ffff8801d131cd38 0000000000000000 ffff8801d131cd38 [ 42.470747] 0000000000000000 ffff8801d0727888 ffffffff814fd953 ffff8801d131cd38 [ 42.478733] Call Trace: [ 42.481294] [] dump_stack+0xc1/0x124 [ 42.486627] [] print_address_description+0x73/0x260 [ 42.493655] [] kasan_report+0x285/0x370 [ 42.499249] [] ? __lock_acquire+0x387e/0x4b50 [ 42.505362] [] __asan_report_load8_noabort+0x14/0x20 [ 42.512080] [] __lock_acquire+0x387e/0x4b50 [ 42.518105] [] ? __lock_acquire+0xb5f/0x4b50 [ 42.524134] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 42.531118] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 42.537925] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 42.544919] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 42.551901] [] lock_acquire+0x15e/0x460 [ 42.557493] [] ? remove_wait_queue+0x14/0x40 [ 42.563518] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 42.569802] [] ? remove_wait_queue+0x14/0x40 [ 42.575826] [] remove_wait_queue+0x14/0x40 [ 42.581680] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 42.588662] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 42.595903] [] ? ep_free+0x1c0/0x1c0 [ 42.601234] [] ep_free+0x93/0x1c0 [ 42.606316] [] ? ep_free+0x1c0/0x1c0 [ 42.611648] [] ep_eventpoll_release+0x44/0x60 [ 42.617760] [] __fput+0x233/0x6d0 [ 42.622843] [] ____fput+0x15/0x20 [ 42.627914] [] task_work_run+0x104/0x180 [ 42.633595] [] do_exit+0x871/0x2a20 [ 42.638841] [] ? handle_mm_fault+0x192d/0x3190 [ 42.645052] [] ? handle_mm_fault+0x3f2/0x3190 [ 42.651164] [] ? release_task+0x1240/0x1240 [ 42.657103] [] do_group_exit+0x108/0x320 [ 42.662782] [] SyS_exit_group+0x1d/0x20 [ 42.668385] [] ? do_group_exit+0x320/0x320 [ 42.674239] [] do_fast_syscall_32+0x314/0x890 [ 42.680352] [] sysenter_flags_fixed+0xd/0x17 [ 42.686377] [ 42.687973] Allocated by task 3325: [ 42.691567] [] save_stack_trace+0x26/0x50 [ 42.697450] [] save_stack+0x43/0xd0 [ 42.702810] [] kasan_kmalloc+0xad/0xe0 [ 42.708432] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 42.715011] [] binder_get_thread+0x181/0x7a0 [ 42.721165] [] binder_poll+0x4a/0x210 [ 42.726698] [] SyS_epoll_ctl+0x10b1/0x2050 [ 42.732666] [] do_fast_syscall_32+0x314/0x890 [ 42.738893] [] sysenter_flags_fixed+0xd/0x17 [ 42.745035] [ 42.746633] Freed by task 3325: [ 42.749876] [] save_stack_trace+0x26/0x50 [ 42.755755] [] save_stack+0x43/0xd0 [ 42.761122] [] kasan_slab_free+0x72/0xc0 [ 42.766913] [] kfree+0xfc/0x300 [ 42.771937] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 42.778687] [] binder_thread_release+0x27d/0x540 [ 42.785191] [] binder_ioctl+0xb94/0x12e0 [ 42.790986] [] compat_SyS_ioctl+0x28a/0x2540 [ 42.797130] [] do_fast_syscall_32+0x314/0x890 [ 42.803361] [] sysenter_flags_fixed+0xd/0x17 [ 42.809506] [ 42.811105] The buggy address belongs to the object at ffff8801d131cc80 [ 42.811105] which belongs to the cache kmalloc-512 of size 512 [ 42.823744] The buggy address is located 184 bytes inside of [ 42.823744] 512-byte region [ffff8801d131cc80, ffff8801d131ce80) [ 42.835586] The buggy address belongs to the page: [ 44.315981] PANIC: double fault, error_code: 0x0 [ 44.320770] CPU: 1 PID: 3325 Comm: syzkaller380159 Not tainted 4.4.112-gd96d95d #24 [ 44.328532] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.337856] task: ffff8801d27caf80 task.stack: ffff8801d0720000 [ 44.343878] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 44.352722] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 44.358140] RAX: ffff8801d27caf80 RBX: ffffea000744c700 RCX: ffffffff8148fea0 [ 44.365386] RDX: 0000000000000000 RSI: ffffffff838a8620 RDI: ffffea000744c700 [ 44.372625] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 44.379862] R10: 0000000000000002 R11: fffffbfff0ad7a1e R12: 0000000000000000 [ 44.387103] R13: ffffffff838a8620 R14: 0000000000000000 R15: 0000000000000000 [ 44.394342] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 44.402537] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 44.408387] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 44.415627] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 44.422866] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 44.430102] Stack: [ 44.432216] [ 44.433814] Call Trace: [ 44.436366] [ 44.438405] Code: e2 06 00 e9 1d fd ff ff 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 41 56 41 55 49 89 f5 41 54 49 89 d4 53 48 89 fb 48 83 ec 08 11 01 ed ff 48 8d 7b 10 48 b8 00 00 00 00 00 fc ff df 48 89 [ 44.465302] Kernel panic - not syncing: Machine halted. [ 44.470633] CPU: 1 PID: 3325 Comm: syzkaller380159 Not tainted 4.4.112-gd96d95d #24 [ 44.478391] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.487897] 0000000000000000 b854057f7361dd98 ffff8801db30ce38 ffffffff81d054ed [ 44.495876] ffffffff83836a60 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 44.503862] 0000000000000000 ffff8801db30cf00 ffffffff81419dca 0000000041b58ab3 [ 44.511829] Call Trace: [ 44.514382] <#DF> [] dump_stack+0xc1/0x124 [ 44.520449] [] panic+0x1aa/0x388 [ 44.525432] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 44.532328] [] ? vprintk_emit+0x242/0x850 [ 44.538093] [] ? dump_page_badflags+0x2f/0x250 [ 44.544290] [] ? vprintk_emit+0x242/0x850 [ 44.550057] [] df_debug+0x2d/0x30 [ 44.555129] [] do_double_fault+0x10b/0x210 [ 44.560982] [] double_fault+0x2d/0x40 [ 44.566400] [] ? dump_page_badflags+0x180/0x250 [ 44.572685] [] ? dump_page_badflags+0x1a/0x250 [ 44.578893] <> [ 44.582242] Dumping ftrace buffer: [ 44.586042] (ftrace buffer empty) [ 44.589721] Kernel Offset: disabled [ 44.593314] Rebooting in 86400 seconds..