[ 16.363924] 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: [ 21.454383] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 21.776265] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available) [ 22.633116] random: sshd: uninitialized urandom read (32 bytes read, 105 bits of entropy available) [ 22.815750] random: sshd: uninitialized urandom read (32 bytes read, 109 bits of entropy available) Warning: Permanently added '10.128.15.234' (ECDSA) to the list of known hosts. [ 28.205976] random: sshd: uninitialized urandom read (32 bytes read, 117 bits of entropy available) executing program [ 28.305318] ================================================================== [ 28.312732] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 28.319366] Read of size 8 at addr ffff8800b4600838 by task syzkaller256195/3328 [ 28.326862] [ 28.328462] CPU: 0 PID: 3328 Comm: syzkaller256195 Not tainted 4.4.110-gdac1439 #13 [ 28.336220] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.345545] 0000000000000000 d532430ea1d99229 ffff8801d14c7830 ffffffff81d04e3d [ 28.353497] ffffea0002d18000 ffff8800b4600838 0000000000000000 ffff8800b4600838 [ 28.361444] 0000000000000000 ffff8801d14c7868 ffffffff814fd1f3 ffff8800b4600838 [ 28.369395] Call Trace: [ 28.371960] [] dump_stack+0xc1/0x124 [ 28.377300] [] print_address_description+0x73/0x260 [ 28.383929] [] kasan_report+0x285/0x370 [ 28.389527] [] ? __lock_acquire+0x387e/0x4b50 [ 28.395639] [] __asan_report_load8_noabort+0x14/0x20 [ 28.402357] [] __lock_acquire+0x387e/0x4b50 [ 28.408296] [] ? __lock_acquire+0xb5f/0x4b50 [ 28.414329] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.421307] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.428285] [] ? __lock_is_held+0xa1/0xf0 [ 28.434049] [] lock_acquire+0x15e/0x460 [ 28.439644] [] ? remove_wait_queue+0x14/0x40 [ 28.445671] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 28.451957] [] ? remove_wait_queue+0x14/0x40 [ 28.457983] [] remove_wait_queue+0x14/0x40 [ 28.463837] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 28.470817] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 28.478060] [] ep_remove+0x41/0x290 [ 28.483304] [] eventpoll_release_file+0xc5/0x140 [ 28.489677] [] __fput+0x521/0x6d0 [ 28.494746] [] ____fput+0x15/0x20 [ 28.499821] [] task_work_run+0x104/0x180 [ 28.505499] [] do_exit+0x871/0x2a20 [ 28.510743] [] ? handle_mm_fault+0x192d/0x3190 [ 28.516941] [] ? handle_mm_fault+0x3f2/0x3190 [ 28.523053] [] ? release_task+0x1240/0x1240 [ 28.529005] [] do_group_exit+0x108/0x320 [ 28.534684] [] SyS_exit_group+0x1d/0x20 [ 28.540273] [] ? do_group_exit+0x320/0x320 [ 28.546129] [] do_fast_syscall_32+0x314/0x890 [ 28.552256] [] sysenter_flags_fixed+0xd/0x17 [ 28.558280] [ 28.559875] Allocated by task 3328: [ 28.563476] [] save_stack_trace+0x26/0x50 [ 28.569359] [] save_stack+0x43/0xd0 [ 28.574728] [] kasan_kmalloc+0xad/0xe0 [ 28.580352] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 28.586924] [] binder_get_thread+0x181/0x7a0 [ 28.593062] [] binder_poll+0x4a/0x210 [ 28.598592] [] SyS_epoll_ctl+0x10b1/0x2050 [ 28.604554] [] do_fast_syscall_32+0x314/0x890 [ 28.610776] [] sysenter_flags_fixed+0xd/0x17 [ 28.616920] [ 28.618513] Freed by task 3328: [ 28.621755] [] save_stack_trace+0x26/0x50 [ 28.627632] [] save_stack+0x43/0xd0 [ 28.632984] [] kasan_slab_free+0x72/0xc0 [ 28.638774] [] kfree+0xfc/0x300 [ 28.643780] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 28.650526] [] binder_thread_release+0x27d/0x540 [ 28.657010] [] binder_ioctl+0xb94/0x12e0 [ 28.662796] [] compat_SyS_ioctl+0x28a/0x2540 [ 28.668945] [] do_fast_syscall_32+0x314/0x890 [ 28.675192] [] sysenter_flags_fixed+0xd/0x17 [ 28.681331] [ 28.682926] The buggy address belongs to the object at ffff8800b4600780 [ 28.682926] which belongs to the cache kmalloc-512 of size 512 [ 28.695547] The buggy address is located 184 bytes inside of [ 28.695547] 512-byte region [ffff8800b4600780, ffff8800b4600980) [ 28.707389] The buggy address belongs to the page: [ 30.106691] PANIC: double fault, error_code: 0x0 [ 30.111502] CPU: 0 PID: 3328 Comm: syzkaller256195 Not tainted 4.4.110-gdac1439 #13 [ 30.119274] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.128602] task: ffff8800b52ac740 task.stack: ffff8801d14c0000 [ 30.134624] RIP: 0010:[] [] dump_page_badflags+0x8/0x250 [ 30.143379] RSP: 0018:ffff880100000000 EFLAGS: 00010046 [ 30.148807] RAX: ffff8800b52ac740 RBX: ffffea0002d18000 RCX: ffffffff8148f740 [ 30.156056] RDX: 0000000000000000 RSI: ffffffff838a8320 RDI: ffffea0002d18000 [ 30.163297] RBP: ffff880100000010 R08: 0000000000000001 R09: 0000000000000000 [ 30.170532] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 30.177770] R13: ffffffff838a8320 R14: 0000000000000000 R15: 0000000000000000 [ 30.185008] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 30.193210] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 30.199075] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 30.206315] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 30.213562] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 30.220796] Stack: [ 30.222910] [ 30.224504] Call Trace: [ 30.227062] [ 30.229101] Code: 00 e9 83 fd ff ff e8 a8 e2 06 00 e9 50 fd ff ff e8 9e 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 e8 61 06 [ 30.255764] Kernel panic - not syncing: Machine halted. [ 30.261094] CPU: 0 PID: 3328 Comm: syzkaller256195 Not tainted 4.4.110-gdac1439 #13 [ 30.268856] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.278177] 0000000000000000 d532430ea1d99229 ffff8801db20ce38 ffffffff81d04e3d [ 30.286131] ffffffff838367c0 ffff8801db20cf10 ffffffff83808040 ffff880100000000 [ 30.294095] 0000000000000000 ffff8801db20cf00 ffffffff814197fa 0000000041b58ab3 [ 30.302061] Call Trace: [ 30.304760] <#DF> [] dump_stack+0xc1/0x124 [ 30.310844] [] panic+0x1aa/0x388 [ 30.315830] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 30.322723] [] ? vprintk_emit+0x242/0x850 [ 30.328572] [] ? dump_page_badflags+0x1d/0x250 [ 30.334777] [] ? vprintk_emit+0x242/0x850 [ 30.340545] [] df_debug+0x2d/0x30 [ 30.345614] [] do_double_fault+0x10b/0x210 [ 30.351464] [] double_fault+0x2d/0x40 [ 30.356879] [] ? dump_page_badflags+0x180/0x250 [ 30.363161] [] ? dump_page_badflags+0x8/0x250 [ 30.369267] <> [ 30.372604] Dumping ftrace buffer: [ 30.376397] (ftrace buffer empty) [ 30.380090] Kernel Offset: disabled [ 30.383680] Rebooting in 86400 seconds..