[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.790076] 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: [ 21.404917] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 21.791347] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 22.732512] random: sshd: uninitialized urandom read (32 bytes read, 109 bits of entropy available) [ 28.042342] random: sshd: uninitialized urandom read (32 bytes read, 117 bits of entropy available) Warning: Permanently added '10.128.0.56' (ECDSA) to the list of known hosts. [ 33.472767] random: sshd: uninitialized urandom read (32 bytes read, 123 bits of entropy available) executing program [ 33.573782] ================================================================== [ 33.581189] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 33.587828] Read of size 8 at addr ffff8800b57c7738 by task syzkaller150742/3330 [ 33.595334] [ 33.596945] CPU: 1 PID: 3330 Comm: syzkaller150742 Not tainted 4.4.113-ge70c132 #27 [ 33.604727] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.614063] 0000000000000000 b89135eb7c5efb3b ffff8801cfc0f870 ffffffff81d0278d [ 33.622057] ffffea0002d5f180 ffff8800b57c7738 0000000000000000 ffff8800b57c7738 [ 33.630053] 0000000000000000 ffff8801cfc0f8a8 ffffffff814fd053 ffff8800b57c7738 [ 33.638034] Call Trace: [ 33.640599] [] dump_stack+0xc1/0x124 [ 33.645944] [] print_address_description+0x73/0x260 [ 33.652591] [] kasan_report+0x285/0x370 [ 33.658210] [] ? __lock_acquire+0x387e/0x4b50 [ 33.664344] [] __asan_report_load8_noabort+0x14/0x20 [ 33.671099] [] __lock_acquire+0x387e/0x4b50 [ 33.677061] [] ? __lock_acquire+0xb5f/0x4b50 [ 33.683109] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 33.690123] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 33.696943] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 33.703931] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 33.710915] [] lock_acquire+0x15e/0x460 [ 33.716514] [] ? remove_wait_queue+0x14/0x40 [ 33.722563] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 33.728852] [] ? remove_wait_queue+0x14/0x40 [ 33.734881] [] remove_wait_queue+0x14/0x40 [ 33.740767] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 33.747770] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 33.755028] [] ? ep_free+0x1c0/0x1c0 [ 33.760362] [] ep_free+0x93/0x1c0 [ 33.765437] [] ? ep_free+0x1c0/0x1c0 [ 33.770779] [] ep_eventpoll_release+0x44/0x60 [ 33.776917] [] __fput+0x233/0x6d0 [ 33.782009] [] ____fput+0x15/0x20 [ 33.787101] [] task_work_run+0x104/0x180 [ 33.792789] [] do_exit+0x82a/0x2a10 [ 33.798048] [] ? release_task+0x1240/0x1240 [ 33.803991] [] do_group_exit+0x108/0x320 [ 33.809672] [] SyS_exit_group+0x1d/0x20 [ 33.815270] [] ? do_group_exit+0x320/0x320 [ 33.821129] [] do_fast_syscall_32+0x314/0x890 [ 33.827251] [] sysenter_flags_fixed+0xd/0x17 [ 33.833276] [ 33.834877] Allocated by task 3330: [ 33.838473] [] save_stack_trace+0x26/0x50 [ 33.844362] [] save_stack+0x43/0xd0 [ 33.849735] [] kasan_kmalloc+0xad/0xe0 [ 33.855365] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 33.861948] [] binder_get_thread+0x15d/0x750 [ 33.868107] [] binder_poll+0x4a/0x210 [ 33.873649] [] SyS_epoll_ctl+0x10b1/0x2040 [ 33.879638] [] do_fast_syscall_32+0x314/0x890 [ 33.885878] [] sysenter_flags_fixed+0xd/0x17 [ 33.892566] [ 33.894173] Freed by task 3330: [ 33.897418] [] save_stack_trace+0x26/0x50 [ 33.903320] [] save_stack+0x43/0xd0 [ 33.908687] [] kasan_slab_free+0x72/0xc0 [ 33.914495] [] kfree+0xfc/0x300 [ 33.919519] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 33.926276] [] binder_thread_release+0x27d/0x540 [ 33.932783] [] binder_ioctl+0xb94/0x12e0 [ 33.938609] [] compat_SyS_ioctl+0x28a/0x2540 [ 33.944761] [] do_fast_syscall_32+0x314/0x890 [ 33.951006] [] sysenter_flags_fixed+0xd/0x17 [ 33.957178] [ 33.958782] The buggy address belongs to the object at ffff8800b57c7680 [ 33.958782] which belongs to the cache kmalloc-512 of size 512 [ 33.971417] The buggy address is located 184 bytes inside of [ 33.971417] 512-byte region [ffff8800b57c7680, ffff8800b57c7880) [ 33.983267] The buggy address belongs to the page: [ 35.427489] PANIC: double fault, error_code: 0x0 [ 35.432277] CPU: 1 PID: 3330 Comm: syzkaller150742 Not tainted 4.4.113-ge70c132 #27 [ 35.440049] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.449375] task: ffff8801d2390000 task.stack: ffff8801cfc08000 [ 35.455400] RIP: 0010:[] [] dump_page_badflags+0x8/0x250 [ 35.464165] RSP: 0018:ffff880100000000 EFLAGS: 00010046 [ 35.469584] RAX: ffff8801d2390000 RBX: ffffea0002d5f180 RCX: ffffffff8148f8d0 [ 35.476824] RDX: 0000000000000000 RSI: ffffffff838a8de0 RDI: ffffea0002d5f180 [ 35.484063] RBP: ffff880100000010 R08: 0000000000000001 R09: 0000000000000000 [ 35.491313] R10: 0000000000000002 R11: fffffbfff0ad7e26 R12: 0000000000000000 [ 35.498558] R13: ffffffff838a8de0 R14: 0000000000000000 R15: 0000000000000000 [ 35.505801] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 35.514001] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 35.519860] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 35.527114] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 35.534354] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 35.541593] Stack: [ 35.543711] [ 35.545306] Call Trace: [ 35.547859] [ 35.549887] 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 [ 35.576778] Kernel panic - not syncing: Machine halted. [ 35.582112] CPU: 1 PID: 3330 Comm: syzkaller150742 Not tainted 4.4.113-ge70c132 #27 [ 35.589874] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.599197] 0000000000000000 b89135eb7c5efb3b ffff8801db30ce38 ffffffff81d0278d [ 35.607190] ffffffff83837200 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 35.615153] 0000000000000000 ffff8801db30cf00 ffffffff81419b6a 0000000041b58ab3 [ 35.623122] Call Trace: [ 35.625671] <#DF> [] dump_stack+0xc1/0x124 [ 35.631744] [] panic+0x1aa/0x388 [ 35.636732] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 35.643638] [] ? vprintk_emit+0x242/0x850 [ 35.649408] [] ? dump_page_badflags+0x1d/0x250 [ 35.655620] [] ? vprintk_emit+0x242/0x850 [ 35.661389] [] df_debug+0x2d/0x30 [ 35.666462] [] do_double_fault+0x10b/0x210 [ 35.672322] [] double_fault+0x2d/0x40 [ 35.677749] [] ? dump_page_badflags+0x180/0x250 [ 35.684043] [] ? dump_page_badflags+0x8/0x250 [ 35.690170] <> [ 35.693483] Dumping ftrace buffer: [ 35.697291] (ftrace buffer empty) [ 35.700987] Kernel Offset: disabled [ 35.704587] Rebooting in 86400 seconds..