[ 15.906895] random: sshd: uninitialized urandom read (32 bytes read, 33 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: [ 19.414494] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 19.748997] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 20.549205] random: sshd: uninitialized urandom read (32 bytes read, 95 bits of entropy available) [ 27.978745] random: sshd: uninitialized urandom read (32 bytes read, 103 bits of entropy available) Warning: Permanently added '10.128.15.241' (ECDSA) to the list of known hosts. [ 33.355945] random: sshd: uninitialized urandom read (32 bytes read, 109 bits of entropy available) executing program [ 33.451096] ================================================================== [ 33.458464] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 33.465098] Read of size 8 at addr ffff8801d2972d38 by task syzkaller608109/3316 [ 33.472595] [ 33.474193] CPU: 1 PID: 3316 Comm: syzkaller608109 Not tainted 4.4.112-g5f6325b #21 [ 33.481961] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.491285] 0000000000000000 b12dd01ced9c8cee ffff8801d1f47850 ffffffff81d0579d [ 33.499248] ffffea00074a5c80 ffff8801d2972d38 0000000000000000 ffff8801d2972d38 [ 33.507209] 0000000000000000 ffff8801d1f47888 ffffffff814fd9f3 ffff8801d2972d38 [ 33.515167] Call Trace: [ 33.517725] [] dump_stack+0xc1/0x124 [ 33.523065] [] print_address_description+0x73/0x260 [ 33.529698] [] kasan_report+0x285/0x370 [ 33.535289] [] ? __lock_acquire+0x387e/0x4b50 [ 33.541400] [] __asan_report_load8_noabort+0x14/0x20 [ 33.548122] [] __lock_acquire+0x387e/0x4b50 [ 33.554066] [] ? __lock_acquire+0xb5f/0x4b50 [ 33.560092] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 33.567072] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 33.573877] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 33.580857] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 33.587837] [] lock_acquire+0x15e/0x460 [ 33.593432] [] ? remove_wait_queue+0x14/0x40 [ 33.599633] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 33.605923] [] ? remove_wait_queue+0x14/0x40 [ 33.611951] [] remove_wait_queue+0x14/0x40 [ 33.617807] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 33.624788] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 33.632029] [] ? ep_free+0x1c0/0x1c0 [ 33.637359] [] ep_free+0x93/0x1c0 [ 33.642428] [] ? ep_free+0x1c0/0x1c0 [ 33.647757] [] ep_eventpoll_release+0x44/0x60 [ 33.653868] [] __fput+0x233/0x6d0 [ 33.658939] [] ____fput+0x15/0x20 [ 33.664013] [] task_work_run+0x104/0x180 [ 33.669697] [] do_exit+0x871/0x2a20 [ 33.674942] [] ? handle_mm_fault+0x192d/0x3190 [ 33.681143] [] ? handle_mm_fault+0x3f2/0x3190 [ 33.687255] [] ? release_task+0x1240/0x1240 [ 33.693203] [] do_group_exit+0x108/0x320 [ 33.698882] [] SyS_exit_group+0x1d/0x20 [ 33.704474] [] ? do_group_exit+0x320/0x320 [ 33.710328] [] do_fast_syscall_32+0x314/0x890 [ 33.716441] [] sysenter_flags_fixed+0xd/0x17 [ 33.722466] [ 33.724068] Allocated by task 3316: [ 33.727659] [] save_stack_trace+0x26/0x50 [ 33.733542] [] save_stack+0x43/0xd0 [ 33.738903] [] kasan_kmalloc+0xad/0xe0 [ 33.744523] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 33.751103] [] binder_get_thread+0x181/0x7a0 [ 33.757241] [] binder_poll+0x4a/0x210 [ 33.762770] [] SyS_epoll_ctl+0x10b1/0x2050 [ 33.768742] [] do_fast_syscall_32+0x314/0x890 [ 33.774970] [] sysenter_flags_fixed+0xd/0x17 [ 33.781111] [ 33.782707] Freed by task 3316: [ 33.785951] [] save_stack_trace+0x26/0x50 [ 33.791833] [] save_stack+0x43/0xd0 [ 33.797189] [] kasan_slab_free+0x72/0xc0 [ 33.802979] [] kfree+0xfc/0x300 [ 33.807987] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 33.814730] [] binder_thread_release+0x27d/0x540 [ 33.821214] [] binder_ioctl+0xb94/0x12e0 [ 33.827011] [] compat_SyS_ioctl+0x28a/0x2540 [ 33.833155] [] do_fast_syscall_32+0x314/0x890 [ 33.839380] [] sysenter_flags_fixed+0xd/0x17 [ 33.845524] [ 33.847123] The buggy address belongs to the object at ffff8801d2972c80 [ 33.847123] which belongs to the cache kmalloc-512 of size 512 [ 33.859743] The buggy address is located 184 bytes inside of [ 33.859743] 512-byte region [ffff8801d2972c80, ffff8801d2972e80) [ 33.871580] The buggy address belongs to the page: [ 35.380948] PANIC: double fault, error_code: 0x0 [ 35.385722] CPU: 1 PID: 3316 Comm: syzkaller608109 Not tainted 4.4.112-g5f6325b #21 [ 35.393479] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.402802] task: ffff8800b50197c0 task.stack: ffff8801d1f40000 [ 35.408826] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 35.417663] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 35.423079] RAX: ffff8800b50197c0 RBX: ffffea00074a5c80 RCX: ffffffff8148ff40 [ 35.430314] RDX: 0000000000000000 RSI: ffffffff838a8620 RDI: ffffea00074a5c80 [ 35.437550] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 35.444786] R10: 0000000000000002 R11: fffffbfff0ad7a1e R12: 0000000000000000 [ 35.452021] R13: ffffffff838a8620 R14: 0000000000000000 R15: 0000000000000000 [ 35.459256] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 35.465074] kasan: CONFIG_KASAN_INLINE enabled [ 35.465079] kasan: GPF could be caused by NULL-ptr deref or user memory access [ 35.465081] general protection fault: 0000 [#1] PREEMPT SMP KASAN [ 35.465085] Dumping ftrace buffer: [ 35.465087] (ftrace buffer empty) [ 35.465090] Modules linked in: [ 35.465094] CPU: 0 PID: 1734 Comm: udevd Not tainted 4.4.112-g5f6325b #21 [ 35.465096] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.465098] task: ffff8801d3ae97c0 task.stack: ffff8801d3b90000 [ 35.465108] RIP: 0010:[] [] debug_check_no_obj_freed+0x1a8/0x9b0 [ 35.465110] RSP: 0000:ffff8801d3b97778 EFLAGS: 00010803 [ 35.465112] RAX: 0000000000000286 RBX: ffff8801d0e48380 RCX: 0000000000000005 [ 35.465114] RDX: 1d2000dc1b1d0161 RSI: ffff8801d3b97808 RDI: ffffffff8148ff69 [ 35.465116] RBP: ffff8801d3b97870 R08: 1ffffffff0291fed R09: ffffffff8512b880 [ 35.465118] R10: dead000000000200 R11: 1ffff1003a772eb6 R12: ecff7ee8ffffff45 [ 35.465120] R13: ffff8801d0e48300 R14: e90006e0d8e80b0f R15: dffffc0000000000 [ 35.465123] FS: 00007faa624617a0(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 35.465125] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 35.465127] CR2: 0000000000000000 CR3: 00000001d3b62000 CR4: 0000000000160670 [ 35.465133] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 35.465135] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 35.465135] Stack: [ 35.465140] ffffffff81642370 ffff8801d3b977c0 ffff880100000018 ffff8801d3b978b8 [ 35.465144] 1ffff1003a772efd ffffffff85786bc0 ffff8801d0e49000 ffff8801d0e48380 [ 35.465148] ffffffff842bcb20 a1a7875492e29c4f 0000000000027180 fffffbfff0af0d78 [ 35.465148] Call Trace: [ 35.465155] [] ? expand_corename+0x110/0x110 [ 35.465159] [] ? debug_object_active_state+0x420/0x420 [ 35.465164] [] ? kfree+0xd4/0x300 [ 35.465168] [] ? do_coredump+0xec6/0x2af0 [ 35.465171] [] ? do_coredump+0xec6/0x2af0 [ 35.465174] [] kfree+0xf1/0x300 [ 35.465178] [] do_coredump+0xec6/0x2af0 [ 35.465184] [] ? retint_user+0x8/0x3c [ 35.465188] [] ? dump_align+0x80/0x80 [ 35.465191] [] ? check_preemption_disabled+0x3b/0x200 [ 35.465196] [] ? __lock_is_held+0xa1/0xf0 [ 35.465201] [] ? __sigqueue_free.part.14+0x51/0x60 [ 35.465204] [] ? __sigqueue_free.part.14+0x51/0x60 [ 35.465209] [] ? rcu_read_lock_sched_held+0x103/0x120 [ 35.465213] [] ? kmem_cache_free+0x2a4/0x320 [ 35.465217] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 35.465221] [] get_signal+0x63a/0x1660 [ 35.465226] [] do_signal+0x8b/0x1d40 [ 35.465232] [] ? spurious_fault+0x370/0x370 [ 35.465236] [] ? setup_sigcontext+0x780/0x780 [ 35.465239] [] ? __lock_is_held+0xa1/0xf0 [ 35.465242] [] ? __bad_area_nosemaphore+0x220/0x420 [ 35.465246] [] ? bad_area+0x53/0x80 [ 35.465249] [] ? exit_to_usermode_loop+0xec/0x170 [ 35.465252] [] exit_to_usermode_loop+0x122/0x170 [ 35.465256] [] prepare_exit_to_usermode+0xe3/0x100 [ 35.465259] [] retint_user+0x8/0x3c [ 35.465307] Code: 48 c7 c6 40 fa 75 85 4c 8b 34 0e 4d 85 f6 0f 84 c5 03 00 00 49 ba 00 02 00 00 00 00 ad de 31 c9 48 8d 75 98 4c 89 f2 48 c1 ea 03 <42> 80 3c 3a 00 0f 85 f0 03 00 00 49 8d 7e 18 83 c1 01 49 8b 16 [ 35.465311] RIP [] debug_check_no_obj_freed+0x1a8/0x9b0 [ 35.465312] RSP [ 35.465316] ---[ end trace 7ebeb53337120894 ]--- [ 35.465319] Kernel panic - not syncing: Fatal exception [ 35.833786] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 35.839639] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 35.846885] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 35.854126] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 35.861366] Stack: [ 35.863484] [ 35.865082] Call Trace: [ 35.867635] [ 35.869665] 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 [ 36.574661] Shutting down cpus with NMI [ 36.579038] Dumping ftrace buffer: [ 36.582548] (ftrace buffer empty) [ 36.586228] Kernel Offset: disabled [ 36.589821] Rebooting in 86400 seconds..