[ 16.333772] 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: [ 20.086925] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 20.450522] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 21.412062] random: sshd: uninitialized urandom read (32 bytes read, 114 bits of entropy available) [ 21.587334] random: sshd: uninitialized urandom read (32 bytes read, 118 bits of entropy available) Warning: Permanently added '10.128.0.44' (ECDSA) to the list of known hosts. [ 26.964148] random: sshd: uninitialized urandom read (32 bytes read, 124 bits of entropy available) executing program [ 27.068512] ================================================================== [ 27.075915] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 27.082561] Read of size 8 at addr ffff8801d2c7fc38 by task syzkaller107884/3314 [ 27.090061] [ 27.091663] CPU: 1 PID: 3314 Comm: syzkaller107884 Not tainted 4.4.113-g202e079 #1 [ 27.099343] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.108675] 0000000000000000 73d5630cafcae8f2 ffff8801d0f1f870 ffffffff81d0278d [ 27.116648] ffffea00074b1f80 ffff8801d2c7fc38 0000000000000000 ffff8801d2c7fc38 [ 27.124613] 0000000000000000 ffff8801d0f1f8a8 ffffffff814fd053 ffff8801d2c7fc38 [ 27.132576] Call Trace: [ 27.135136] [] dump_stack+0xc1/0x124 [ 27.140475] [] print_address_description+0x73/0x260 [ 27.147123] [] kasan_report+0x285/0x370 [ 27.152730] [] ? __lock_acquire+0x387e/0x4b50 [ 27.158854] [] __asan_report_load8_noabort+0x14/0x20 [ 27.165604] [] __lock_acquire+0x387e/0x4b50 [ 27.171545] [] ? __lock_acquire+0xb5f/0x4b50 [ 27.177578] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.184574] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 27.191404] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.198402] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.205395] [] lock_acquire+0x15e/0x460 [ 27.210992] [] ? remove_wait_queue+0x14/0x40 [ 27.217021] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 27.223307] [] ? remove_wait_queue+0x14/0x40 [ 27.229349] [] remove_wait_queue+0x14/0x40 [ 27.235205] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 27.242193] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 27.249447] [] ? ep_free+0x1c0/0x1c0 [ 27.254785] [] ep_free+0x93/0x1c0 [ 27.259857] [] ? ep_free+0x1c0/0x1c0 [ 27.265189] [] ep_eventpoll_release+0x44/0x60 [ 27.271304] [] __fput+0x233/0x6d0 [ 27.276380] [] ____fput+0x15/0x20 [ 27.281465] [] task_work_run+0x104/0x180 [ 27.287151] [] do_exit+0x82a/0x2a10 [ 27.292396] [] ? release_task+0x1240/0x1240 [ 27.298334] [] do_group_exit+0x108/0x320 [ 27.304016] [] SyS_exit_group+0x1d/0x20 [ 27.309612] [] ? do_group_exit+0x320/0x320 [ 27.315474] [] do_fast_syscall_32+0x314/0x890 [ 27.321591] [] sysenter_flags_fixed+0xd/0x17 [ 27.327625] [ 27.329226] Allocated by task 3314: [ 27.332820] [] save_stack_trace+0x26/0x50 [ 27.338706] [] save_stack+0x43/0xd0 [ 27.344068] [] kasan_kmalloc+0xad/0xe0 [ 27.349706] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 27.356285] [] binder_get_thread+0x15d/0x750 [ 27.362430] [] binder_poll+0x4a/0x210 [ 27.367971] [] SyS_epoll_ctl+0x10b1/0x2040 [ 27.373943] [] do_fast_syscall_32+0x314/0x890 [ 27.380171] [] sysenter_flags_fixed+0xd/0x17 [ 27.386324] [ 27.387923] Freed by task 3314: [ 27.391166] [] save_stack_trace+0x26/0x50 [ 27.397059] [] save_stack+0x43/0xd0 [ 27.402426] [] kasan_slab_free+0x72/0xc0 [ 27.408222] [] kfree+0xfc/0x300 [ 27.413238] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 27.419997] [] binder_thread_release+0x27d/0x540 [ 27.426494] [] binder_ioctl+0xb94/0x12e0 [ 27.432304] [] compat_SyS_ioctl+0x28a/0x2540 [ 27.438468] [] do_fast_syscall_32+0x314/0x890 [ 27.444698] [] sysenter_flags_fixed+0xd/0x17 [ 27.450846] [ 27.452445] The buggy address belongs to the object at ffff8801d2c7fb80 [ 27.452445] which belongs to the cache kmalloc-512 of size 512 [ 27.465094] The buggy address is located 184 bytes inside of [ 27.465094] 512-byte region [ffff8801d2c7fb80, ffff8801d2c7fd80) [ 27.476958] The buggy address belongs to the page: [ 29.042257] PANIC: double fault, error_code: 0x0 [ 29.047039] CPU: 1 PID: 3314 Comm: syzkaller107884 Not tainted 4.4.113-g202e079 #1 [ 29.054712] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.064035] task: ffff8801d31817c0 task.stack: ffff8801d0f18000 [ 29.070065] RIP: 0010:[] [] dump_page_badflags+0x8/0x250 [ 29.078831] RSP: 0018:ffff880100000000 EFLAGS: 00010046 [ 29.084265] RAX: ffff8801d31817c0 RBX: ffffea00074b1f80 RCX: ffffffff8148f8d0 [ 29.091503] RDX: 0000000000000000 RSI: ffffffff838a8de0 RDI: ffffea00074b1f80 [ 29.098740] RBP: ffff880100000010 R08: 0000000000000001 R09: 0000000000000000 [ 29.105980] R10: 0000000000000002 R11: fffffbfff0ad7e26 R12: 0000000000000000 [ 29.113224] R13: ffffffff838a8de0 R14: 0000000000000000 R15: 0000000000000000 [ 29.120467] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 29.128669] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 29.134519] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 29.141768] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.149008] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.156248] Stack: [ 29.158362] [ 29.159959] Call Trace: [ 29.162512] [ 29.164550] Code: 00 e9 83 fd ff ff e8 78 df 06 00 e9 50 fd ff ff e8 6e df 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 e8 b1 04 [ 29.191349] Kernel panic - not syncing: Machine halted. [ 29.196689] CPU: 1 PID: 3314 Comm: syzkaller107884 Not tainted 4.4.113-g202e079 #1 [ 29.204363] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.213686] 0000000000000000 73d5630cafcae8f2 ffff8801db30ce38 ffffffff81d0278d [ 29.221649] ffffffff83837200 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 29.229624] 0000000000000000 ffff8801db30cf00 ffffffff81419b6a 0000000041b58ab3 [ 29.237605] Call Trace: [ 29.240155] <#DF> [] dump_stack+0xc1/0x124 [ 29.246222] [] panic+0x1aa/0x388 [ 29.251211] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 29.258110] [] ? vprintk_emit+0x242/0x850 [ 29.263886] [] ? dump_page_badflags+0x1d/0x250 [ 29.270086] [] ? vprintk_emit+0x242/0x850 [ 29.275853] [] df_debug+0x2d/0x30 [ 29.280938] [] do_double_fault+0x10b/0x210 [ 29.286799] [] double_fault+0x2d/0x40 [ 29.292219] [] ? dump_page_badflags+0x180/0x250 [ 29.298506] [] ? dump_page_badflags+0x8/0x250 [ 29.304614] <> [ 29.308021] Dumping ftrace buffer: [ 29.311823] (ftrace buffer empty) [ 29.315503] Kernel Offset: disabled [ 29.319097] Rebooting in 86400 seconds..