[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.499961] random: sshd: uninitialized urandom read (32 bytes read, 33 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.719070] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 22.083841] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available) [ 22.970682] random: sshd: uninitialized urandom read (32 bytes read, 105 bits of entropy available) [ 27.055653] random: sshd: uninitialized urandom read (32 bytes read, 113 bits of entropy available) Warning: Permanently added '10.128.0.19' (ECDSA) to the list of known hosts. [ 32.561521] random: sshd: uninitialized urandom read (32 bytes read, 118 bits of entropy available) executing program [ 32.656613] ================================================================== [ 32.664008] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 32.670646] Read of size 8 at addr ffff8801d1741c38 by task syzkaller775315/3321 [ 32.678149] [ 32.679750] CPU: 0 PID: 3321 Comm: syzkaller775315 Not tainted 4.4.111-gc2f631b #27 [ 32.687513] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 32.696850] 0000000000000000 38a6814a2191cbea ffff8801d0a678b0 ffffffff81d0513d [ 32.704830] ffffea000745d000 ffff8801d1741c38 0000000000000000 ffff8801d1741c38 [ 32.712801] 0000000000000000 ffff8801d0a678e8 ffffffff814fd433 ffff8801d1741c38 [ 32.720773] Call Trace: [ 32.723332] [] dump_stack+0xc1/0x124 [ 32.728668] [] print_address_description+0x73/0x260 [ 32.735303] [] kasan_report+0x285/0x370 [ 32.740898] [] ? __lock_acquire+0x387e/0x4b50 [ 32.747015] [] __asan_report_load8_noabort+0x14/0x20 [ 32.753738] [] __lock_acquire+0x387e/0x4b50 [ 32.759770] [] ? is_module_text_address+0x2a/0x50 [ 32.766232] [] ? __lock_acquire+0xb5f/0x4b50 [ 32.772260] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 32.779247] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 32.786235] [] ? __lock_is_held+0xa1/0xf0 [ 32.792012] [] lock_acquire+0x15e/0x460 [ 32.797614] [] ? remove_wait_queue+0x14/0x40 [ 32.803644] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 32.809932] [] ? remove_wait_queue+0x14/0x40 [ 32.815960] [] remove_wait_queue+0x14/0x40 [ 32.821816] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 32.828796] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 32.836044] [] ep_remove+0x41/0x290 [ 32.841300] [] eventpoll_release_file+0xc5/0x140 [ 32.847675] [] __fput+0x521/0x6d0 [ 32.852747] [] ____fput+0x15/0x20 [ 32.857820] [] task_work_run+0x104/0x180 [ 32.863503] [] do_exit+0x871/0x2a20 [ 32.868748] [] ? release_task+0x1240/0x1240 [ 32.874698] [] ? SyS_epoll_create+0x190/0x190 [ 32.880812] [] do_group_exit+0x108/0x320 [ 32.886491] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 32.892955] [] SyS_exit_group+0x1d/0x20 [ 32.898549] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 32.905101] [ 32.906701] Allocated by task 3321: [ 32.910292] [] save_stack_trace+0x26/0x50 [ 32.916197] [] save_stack+0x43/0xd0 [ 32.921562] [] kasan_kmalloc+0xad/0xe0 [ 32.927186] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 32.933764] [] binder_get_thread+0x181/0x7a0 [ 32.939912] [] binder_poll+0x4a/0x210 [ 32.945446] [] SyS_epoll_ctl+0x10b1/0x2050 [ 32.951433] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 32.958113] [ 32.959713] Freed by task 3321: [ 32.962960] [] save_stack_trace+0x26/0x50 [ 32.968846] [] save_stack+0x43/0xd0 [ 32.974213] [] kasan_slab_free+0x72/0xc0 [ 32.980022] [] kfree+0xfc/0x300 [ 32.985045] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 32.991809] [] binder_thread_release+0x27d/0x540 [ 32.998306] [] binder_ioctl+0xb94/0x12e0 [ 33.004113] [] do_vfs_ioctl+0x7aa/0xee0 [ 33.009825] [] SyS_ioctl+0x8f/0xc0 [ 33.015098] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 33.021766] [ 33.023369] The buggy address belongs to the object at ffff8801d1741b80 [ 33.023369] which belongs to the cache kmalloc-512 of size 512 [ 33.036000] The buggy address is located 184 bytes inside of [ 33.036000] 512-byte region [ffff8801d1741b80, ffff8801d1741d80) [ 33.047855] The buggy address belongs to the page: [ 34.489144] PANIC: double fault, error_code: 0x0 [ 34.493917] CPU: 0 PID: 3321 Comm: syzkaller775315 Not tainted 4.4.111-gc2f631b #27 [ 34.501856] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.511191] task: ffff8801d12d8000 task.stack: ffff8801d0a60000 [ 34.517219] RIP: 0010:[] [] dump_page_badflags+0x8/0x250 [ 34.525977] RSP: 0018:ffff880100000000 EFLAGS: 00010046 [ 34.531395] RAX: ffff8801d12d8000 RBX: ffffea000745d000 RCX: ffffffff8148f980 [ 34.538638] RDX: 0000000000000000 RSI: ffffffff838a8360 RDI: ffffea000745d000 [ 34.545880] RBP: ffff880100000010 R08: 0000000000000001 R09: 0000000000000000 [ 34.553293] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 34.560534] R13: ffffffff838a8360 R14: 0000000000000000 R15: 0000000000000000 [ 34.567788] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 34.575985] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 34.581836] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 34.589093] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 34.596338] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 34.603575] Stack: [ 34.605701] [ 34.607298] Call Trace: [ 34.609850] [ 34.611877] 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 [ 34.638742] Kernel panic - not syncing: Machine halted. [ 34.644074] CPU: 0 PID: 3321 Comm: syzkaller775315 Not tainted 4.4.111-gc2f631b #27 [ 34.651837] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.661161] 0000000000000000 38a6814a2191cbea ffff8801db20ce38 ffffffff81d0513d [ 34.669146] ffffffff838367c0 ffff8801db20cf10 ffffffff83808040 ffff880100000000 [ 34.677118] 0000000000000000 ffff8801db20cf00 ffffffff81419a3a 0000000041b58ab3 [ 34.685085] Call Trace: [ 34.687636] <#DF> [] dump_stack+0xc1/0x124 [ 34.693703] [] panic+0x1aa/0x388 [ 34.699038] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 34.705944] [] ? vprintk_emit+0x242/0x850 [ 34.711804] [] ? dump_page_badflags+0x1d/0x250 [ 34.718010] [] ? vprintk_emit+0x242/0x850 [ 34.723780] [] df_debug+0x2d/0x30 [ 34.728856] [] do_double_fault+0x10b/0x210 [ 34.734719] [] double_fault+0x2d/0x40 [ 34.741877] [] ? dump_page_badflags+0x180/0x250 [ 34.748165] [] ? dump_page_badflags+0x8/0x250 [ 34.754274] <> [ 34.757623] Dumping ftrace buffer: [ 34.761427] (ftrace buffer empty) [ 34.765194] Kernel Offset: disabled [ 34.768790] Rebooting in 86400 seconds..