[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.086043] 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: [ 21.482584] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 21.777538] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 22.465720] random: sshd: uninitialized urandom read (32 bytes read, 82 bits of entropy available) [ 22.642848] random: sshd: uninitialized urandom read (32 bytes read, 87 bits of entropy available) Warning: Permanently added '10.128.15.212' (ECDSA) to the list of known hosts. [ 28.041998] random: sshd: uninitialized urandom read (32 bytes read, 96 bits of entropy available) executing program [ 28.139872] ================================================================== [ 28.147271] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 28.153904] Read of size 8 at addr ffff8800b5e86ab8 by task syzkaller248814/3317 [ 28.161399] [ 28.162992] CPU: 1 PID: 3317 Comm: syzkaller248814 Not tainted 4.4.107-g610c835 #12 [ 28.170759] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.180088] 0000000000000000 69e40511b2186caf ffff8801d0cdf8b0 ffffffff81d0457d [ 28.188040] ffffea0002d7a180 ffff8800b5e86ab8 0000000000000000 ffff8800b5e86ab8 [ 28.195995] 0000000000000000 ffff8801d0cdf8e8 ffffffff814fbb23 ffff8800b5e86ab8 [ 28.203962] Call Trace: [ 28.206517] [] dump_stack+0xc1/0x124 [ 28.211847] [] print_address_description+0x73/0x260 [ 28.218478] [] kasan_report+0x285/0x370 [ 28.224068] [] ? __lock_acquire+0x387e/0x4b50 [ 28.230175] [] __asan_report_load8_noabort+0x14/0x20 [ 28.236894] [] __lock_acquire+0x387e/0x4b50 [ 28.242831] [] ? is_module_text_address+0x2a/0x50 [ 28.249288] [] ? __lock_acquire+0xb5f/0x4b50 [ 28.255319] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.262295] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.269269] [] ? __lock_is_held+0xa1/0xf0 [ 28.275031] [] lock_acquire+0x15e/0x460 [ 28.280624] [] ? remove_wait_queue+0x14/0x40 [ 28.286649] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 28.292934] [] ? remove_wait_queue+0x14/0x40 [ 28.298957] [] remove_wait_queue+0x14/0x40 [ 28.304821] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 28.311801] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 28.319048] [] ep_remove+0x41/0x290 [ 28.324291] [] eventpoll_release_file+0xc5/0x140 [ 28.330672] [] __fput+0x521/0x6d0 [ 28.335748] [] ____fput+0x15/0x20 [ 28.340819] [] task_work_run+0x104/0x180 [ 28.346493] [] do_exit+0x871/0x2a20 [ 28.351737] [] ? release_task+0x1240/0x1240 [ 28.357686] [] ? SyS_epoll_create+0x190/0x190 [ 28.363797] [] do_group_exit+0x108/0x320 [ 28.369473] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 28.375934] [] SyS_exit_group+0x1d/0x20 [ 28.381528] [] entry_SYSCALL_64_fastpath+0x16/0x76 [ 28.388068] [ 28.389662] Allocated by task 3317: [ 28.393261] [] save_stack_trace+0x26/0x50 [ 28.399136] [] save_stack+0x43/0xd0 [ 28.404489] [] kasan_kmalloc+0xad/0xe0 [ 28.410102] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 28.416671] [] binder_get_thread+0x181/0x7a0 [ 28.422806] [] binder_poll+0x4a/0x210 [ 28.428336] [] SyS_epoll_ctl+0x10b1/0x2050 [ 28.434306] [] entry_SYSCALL_64_fastpath+0x16/0x76 [ 28.440964] [ 28.442559] Freed by task 3317: [ 28.445799] [] save_stack_trace+0x26/0x50 [ 28.451673] [] save_stack+0x43/0xd0 [ 28.457028] [] kasan_slab_free+0x72/0xc0 [ 28.462824] [] kfree+0xfc/0x300 [ 28.467832] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 28.474583] [] binder_thread_release+0x27d/0x540 [ 28.481073] [] binder_ioctl+0xb94/0x12e0 [ 28.486860] [] do_vfs_ioctl+0x7aa/0xee0 [ 28.492561] [] SyS_ioctl+0x8f/0xc0 [ 28.497828] [] entry_SYSCALL_64_fastpath+0x16/0x76 [ 28.504483] [ 28.506075] The buggy address belongs to the object at ffff8800b5e86a00 [ 28.506075] which belongs to the cache kmalloc-512 of size 512 [ 28.518711] The buggy address is located 184 bytes inside of [ 28.518711] 512-byte region [ffff8800b5e86a00, ffff8800b5e86c00) [ 28.530549] The buggy address belongs to the page: [ 29.925087] PANIC: double fault, error_code: 0x0 [ 29.929866] CPU: 1 PID: 3317 Comm: syzkaller248814 Not tainted 4.4.107-g610c835 #12 [ 29.937625] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.946947] task: ffff8801d18b8000 task.stack: ffff8801d0cd8000 [ 29.952967] RIP: 0010:[] [] dump_page_badflags+0x8/0x250 [ 29.961715] RSP: 0018:ffff880100000000 EFLAGS: 00010046 [ 29.967128] RAX: ffff8801d18b8000 RBX: ffffea0002d7a180 RCX: ffffffff8148e4e0 [ 29.974374] RDX: 0000000000000000 RSI: ffffffff838a7f60 RDI: ffffea0002d7a180 [ 29.981611] RBP: ffff880100000010 R08: 0000000000000001 R09: 0000000000000000 [ 29.988844] R10: 0000000000000002 R11: fffffbfff0ad641e R12: 0000000000000000 [ 29.996079] R13: ffffffff838a7f60 R14: 0000000000000000 R15: 0000000000000000 [ 30.003318] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 30.011529] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 30.017377] CR2: ffff8800fffffff8 CR3: 000000000420b000 CR4: 00000000001406e0 [ 30.024614] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 30.031850] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 30.039085] Stack: [ 30.041199] [ 30.042792] Call Trace: [ 30.045339] [ 30.047367] Code: 00 e9 83 fd ff ff e8 38 de 06 00 e9 50 fd ff ff e8 2e de 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 f7 [ 30.073943] Kernel panic - not syncing: Machine halted. [ 30.079274] CPU: 1 PID: 3317 Comm: syzkaller248814 Not tainted 4.4.107-g610c835 #12 [ 30.087028] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.096348] 0000000000000000 69e40511b2186caf ffff8801db309e38 ffffffff81d0457d [ 30.104295] ffffffff83836620 ffff8801db309f10 ffffffff83808040 ffff880100000000 [ 30.112243] 0000000000000000 ffff8801db309f00 ffffffff8141774a 0000000041b58ab3 [ 30.120183] Call Trace: [ 30.122729] <#DF> [] dump_stack+0xc1/0x124 [ 30.128790] [] panic+0x1aa/0x388 [ 30.133770] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 30.140662] [] ? vprintk_emit+0x242/0x850 [ 30.146424] [] ? dump_page_badflags+0x1d/0x250 [ 30.152620] [] ? vprintk_emit+0x242/0x850 [ 30.158383] [] df_debug+0x2d/0x30 [ 30.163451] [] do_double_fault+0x10b/0x210 [ 30.169299] [] double_fault+0x2d/0x40 [ 30.174716] [] ? dump_page_badflags+0x180/0x250 [ 30.181001] [] ? dump_page_badflags+0x8/0x250 [ 30.187107] <> [ 30.190065] Dumping ftrace buffer: [ 30.193859] (ftrace buffer empty) [ 30.197547] Kernel Offset: disabled [ 30.201138] Rebooting in 86400 seconds..