[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.153819] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.466419] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 21.821838] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 22.752255] random: sshd: uninitialized urandom read (32 bytes read, 112 bits of entropy available) [ 22.919787] random: sshd: uninitialized urandom read (32 bytes read, 116 bits of entropy available) Warning: Permanently added '10.128.15.211' (ECDSA) to the list of known hosts. [ 28.293828] random: sshd: uninitialized urandom read (32 bytes read, 121 bits of entropy available) executing program [ 28.391366] ================================================================== [ 28.398754] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 28.405396] Read of size 8 at addr ffff8800b418b738 by task syzkaller246735/3318 [ 28.412896] [ 28.414493] CPU: 1 PID: 3318 Comm: syzkaller246735 Not tainted 4.4.112-g3fc4284 #25 [ 28.422251] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.431581] 0000000000000000 932335601de98058 ffff8801d0f5f850 ffffffff81d054ed [ 28.439550] ffffea0002d06280 ffff8800b418b738 0000000000000000 ffff8800b418b738 [ 28.447519] 0000000000000000 ffff8801d0f5f888 ffffffff814fd953 ffff8800b418b738 [ 28.455479] Call Trace: [ 28.458036] [] dump_stack+0xc1/0x124 [ 28.463367] [] print_address_description+0x73/0x260 [ 28.469998] [] kasan_report+0x285/0x370 [ 28.475593] [] ? __lock_acquire+0x387e/0x4b50 [ 28.481710] [] __asan_report_load8_noabort+0x14/0x20 [ 28.488433] [] __lock_acquire+0x387e/0x4b50 [ 28.494373] [] ? __lock_acquire+0xb5f/0x4b50 [ 28.500396] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.507386] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 28.514194] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.521176] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.528164] [] lock_acquire+0x15e/0x460 [ 28.533763] [] ? remove_wait_queue+0x14/0x40 [ 28.539796] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 28.546082] [] ? remove_wait_queue+0x14/0x40 [ 28.552105] [] remove_wait_queue+0x14/0x40 [ 28.557959] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 28.564943] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 28.572201] [] ? ep_free+0x1c0/0x1c0 [ 28.577536] [] ep_free+0x93/0x1c0 [ 28.582609] [] ? ep_free+0x1c0/0x1c0 [ 28.587943] [] ep_eventpoll_release+0x44/0x60 [ 28.594060] [] __fput+0x233/0x6d0 [ 28.599129] [] ____fput+0x15/0x20 [ 28.604200] [] task_work_run+0x104/0x180 [ 28.609879] [] do_exit+0x871/0x2a20 [ 28.615124] [] ? handle_mm_fault+0x192d/0x3190 [ 28.621323] [] ? handle_mm_fault+0x3f2/0x3190 [ 28.627437] [] ? release_task+0x1240/0x1240 [ 28.633378] [] do_group_exit+0x108/0x320 [ 28.639058] [] SyS_exit_group+0x1d/0x20 [ 28.644647] [] ? do_group_exit+0x320/0x320 [ 28.650507] [] do_fast_syscall_32+0x314/0x890 [ 28.656635] [] sysenter_flags_fixed+0xd/0x17 [ 28.662660] [ 28.664258] Allocated by task 3318: [ 28.667847] [] save_stack_trace+0x26/0x50 [ 28.673727] [] save_stack+0x43/0xd0 [ 28.679086] [] kasan_kmalloc+0xad/0xe0 [ 28.684714] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 28.691290] [] binder_get_thread+0x181/0x7a0 [ 28.697436] [] binder_poll+0x4a/0x210 [ 28.702969] [] SyS_epoll_ctl+0x10b1/0x2050 [ 28.708943] [] do_fast_syscall_32+0x314/0x890 [ 28.715175] [] sysenter_flags_fixed+0xd/0x17 [ 28.721318] [ 28.722913] Freed by task 3318: [ 28.726157] [] save_stack_trace+0x26/0x50 [ 28.732038] [] save_stack+0x43/0xd0 [ 28.737399] [] kasan_slab_free+0x72/0xc0 [ 28.743194] [] kfree+0xfc/0x300 [ 28.748204] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 28.754955] [] binder_thread_release+0x27d/0x540 [ 28.761446] [] binder_ioctl+0xb94/0x12e0 [ 28.767239] [] compat_SyS_ioctl+0x28a/0x2540 [ 28.773386] [] do_fast_syscall_32+0x314/0x890 [ 28.779629] [] sysenter_flags_fixed+0xd/0x17 [ 28.785775] [ 28.787371] The buggy address belongs to the object at ffff8800b418b680 [ 28.787371] which belongs to the cache kmalloc-512 of size 512 [ 28.799994] The buggy address is located 184 bytes inside of [ 28.799994] 512-byte region [ffff8800b418b680, ffff8800b418b880) [ 28.811836] The buggy address belongs to the page: [ 30.278139] PANIC: double fault, error_code: 0x0 [ 30.282917] CPU: 1 PID: 3318 Comm: syzkaller246735 Not tainted 4.4.112-g3fc4284 #25 [ 30.290683] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.300006] task: ffff8800b4ac5f00 task.stack: ffff8801d0f58000 [ 30.306029] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 30.314878] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 30.320292] RAX: ffff8800b4ac5f00 RBX: ffffea0002d06280 RCX: ffffffff8148fea0 [ 30.327530] RDX: 0000000000000000 RSI: ffffffff838a8620 RDI: ffffea0002d06280 [ 30.334768] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 30.342007] R10: 0000000000000002 R11: fffffbfff0ad7a1e R12: 0000000000000000 [ 30.349244] R13: ffffffff838a8620 R14: 0000000000000000 R15: 0000000000000000 [ 30.356481] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 30.364674] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 30.370525] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 30.377767] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 30.385008] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 30.392253] Stack: [ 30.394370] [ 30.395965] Call Trace: [ 30.398514] [ 30.400543] 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 [ 30.427311] Kernel panic - not syncing: Machine halted. [ 30.432644] CPU: 1 PID: 3318 Comm: syzkaller246735 Not tainted 4.4.112-g3fc4284 #25 [ 30.440403] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.449723] 0000000000000000 932335601de98058 ffff8801db30ce38 ffffffff81d054ed [ 30.457685] ffffffff83836a60 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 30.465648] 0000000000000000 ffff8801db30cf00 ffffffff81419dca 0000000041b58ab3 [ 30.473614] Call Trace: [ 30.476162] <#DF> [] dump_stack+0xc1/0x124 [ 30.482225] [] panic+0x1aa/0x388 [ 30.487208] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 30.494110] [] ? vprintk_emit+0x242/0x850 [ 30.499875] [] ? dump_page_badflags+0x2f/0x250 [ 30.506079] [] ? vprintk_emit+0x242/0x850 [ 30.511845] [] df_debug+0x2d/0x30 [ 30.516916] [] do_double_fault+0x10b/0x210 [ 30.522768] [] double_fault+0x2d/0x40 [ 30.528187] [] ? dump_page_badflags+0x180/0x250 [ 30.534485] [] ? dump_page_badflags+0x1a/0x250 [ 30.540690] <> [ 30.544068] Dumping ftrace buffer: [ 30.547868] (ftrace buffer empty) [ 30.551554] Kernel Offset: disabled [ 30.555150] Rebooting in 86400 seconds..