[ 16.316415] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 20.413448] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 20.706817] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 21.586338] random: sshd: uninitialized urandom read (32 bytes read, 108 bits of entropy available) [ 21.755341] random: sshd: uninitialized urandom read (32 bytes read, 112 bits of entropy available) Warning: Permanently added '10.128.15.242' (ECDSA) to the list of known hosts. [ 27.130969] random: sshd: uninitialized urandom read (32 bytes read, 120 bits of entropy available) executing program [ 27.226883] ================================================================== [ 27.234285] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 27.240923] Read of size 8 at addr ffff8801d0afc5b8 by task syzkaller122763/3314 [ 27.248432] [ 27.250046] CPU: 1 PID: 3314 Comm: syzkaller122763 Not tainted 4.4.111-g1849cd3 #19 [ 27.257808] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.267137] 0000000000000000 9eafd24318a31a34 ffff8801d0b6f850 ffffffff81d0509d [ 27.275120] ffffea000742bf00 ffff8801d0afc5b8 0000000000000000 ffff8801d0afc5b8 [ 27.283084] 0000000000000000 ffff8801d0b6f888 ffffffff814fd433 ffff8801d0afc5b8 [ 27.291050] Call Trace: [ 27.293608] [] dump_stack+0xc1/0x124 [ 27.298943] [] print_address_description+0x73/0x260 [ 27.305577] [] kasan_report+0x285/0x370 [ 27.311179] [] ? __lock_acquire+0x387e/0x4b50 [ 27.317292] [] __asan_report_load8_noabort+0x14/0x20 [ 27.324014] [] __lock_acquire+0x387e/0x4b50 [ 27.329956] [] ? __lock_acquire+0xb5f/0x4b50 [ 27.335985] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.342965] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 27.349772] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.356755] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.363750] [] lock_acquire+0x15e/0x460 [ 27.369344] [] ? remove_wait_queue+0x14/0x40 [ 27.375371] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 27.381659] [] ? remove_wait_queue+0x14/0x40 [ 27.387688] [] remove_wait_queue+0x14/0x40 [ 27.393542] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 27.400529] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 27.407785] [] ? ep_free+0x1c0/0x1c0 [ 27.413122] [] ep_free+0x93/0x1c0 [ 27.418191] [] ? ep_free+0x1c0/0x1c0 [ 27.423525] [] ep_eventpoll_release+0x44/0x60 [ 27.429640] [] __fput+0x233/0x6d0 [ 27.434712] [] ____fput+0x15/0x20 [ 27.439800] [] task_work_run+0x104/0x180 [ 27.445497] [] do_exit+0x871/0x2a20 [ 27.450755] [] ? handle_mm_fault+0x192d/0x3190 [ 27.456963] [] ? handle_mm_fault+0x3f2/0x3190 [ 27.463076] [] ? release_task+0x1240/0x1240 [ 27.469017] [] do_group_exit+0x108/0x320 [ 27.474695] [] SyS_exit_group+0x1d/0x20 [ 27.480289] [] ? do_group_exit+0x320/0x320 [ 27.486148] [] do_fast_syscall_32+0x314/0x890 [ 27.492261] [] sysenter_flags_fixed+0xd/0x17 [ 27.498289] [ 27.499886] Allocated by task 3314: [ 27.503478] [] save_stack_trace+0x26/0x50 [ 27.509364] [] save_stack+0x43/0xd0 [ 27.514721] [] kasan_kmalloc+0xad/0xe0 [ 27.520345] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 27.526920] [] binder_get_thread+0x181/0x7a0 [ 27.533062] [] binder_poll+0x4a/0x210 [ 27.538592] [] SyS_epoll_ctl+0x10b1/0x2050 [ 27.544569] [] do_fast_syscall_32+0x314/0x890 [ 27.550801] [] sysenter_flags_fixed+0xd/0x17 [ 27.556942] [ 27.558537] Freed by task 3314: [ 27.561779] [] save_stack_trace+0x26/0x50 [ 27.567679] [] save_stack+0x43/0xd0 [ 27.573041] [] kasan_slab_free+0x72/0xc0 [ 27.578833] [] kfree+0xfc/0x300 [ 27.583845] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 27.590603] [] binder_thread_release+0x27d/0x540 [ 27.597094] [] binder_ioctl+0xb94/0x12e0 [ 27.602889] [] compat_SyS_ioctl+0x28a/0x2540 [ 27.609031] [] do_fast_syscall_32+0x314/0x890 [ 27.615268] [] sysenter_flags_fixed+0xd/0x17 [ 27.621417] [ 27.623014] The buggy address belongs to the object at ffff8801d0afc500 [ 27.623014] which belongs to the cache kmalloc-512 of size 512 [ 27.635640] The buggy address is located 184 bytes inside of [ 27.635640] 512-byte region [ffff8801d0afc500, ffff8801d0afc700) [ 27.647481] The buggy address belongs to the page: [ 28.639003] kasan: CONFIG_KASAN_INLINE enabled [ 28.643461] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN [ 28.656404] Dumping ftrace buffer: [ 28.659936] (ftrace buffer empty) [ 28.663643] Modules linked in: [ 28.666959] CPU: 0 PID: 490 Comm: khugepaged Not tainted 4.4.111-g1849cd3 #19 [ 28.674224] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.683588] task: ffff8800bbbe8000 task.stack: ffff8800bac08000 [ 28.689639] RIP: 0010:[] [] debug_check_no_obj_freed+0x1a8/0x9b0 [ 28.699142] RSP: 0018:ffff8800bac0f8f8 EFLAGS: 00010803 [ 28.704586] RAX: 0000000000000282 RBX: ffff8801cc800000 RCX: 0000000000000004 [ 28.711855] RDX: 1d2000dc1b1d0161 RSI: ffff8800bac0f988 RDI: ffffffff8148f9a9 [ 28.719123] RBP: ffff8800bac0f9f0 R08: 1ffffffff0291f35 R09: ffffffff8512a880 [ 28.726395] R10: dead000000000200 R11: 1ffff10017581ee6 R12: ed04cee8ffffff45 [ 28.733667] R13: ffff8801cc600000 R14: e90006e0d8e80b0f R15: dffffc0000000000 [ 28.740944] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 28.749167] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 28.755043] CR2: 000055f5cb3300d0 CR3: 00000000b45d8000 CR4: 0000000000160670 [ 28.762400] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 28.769668] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 28.776933] Stack: [ 28.779077] ffff8801db223448 ffff8800bbbe8000 ffff8800bbbe8870 00000000000000ef [ 28.787134] 1ffff10017581f2d ffffffff8582f080 ffff8801cc800000 ffff8801cc800000 [ 28.795174] 0000000000000046 0000000000000246 00000000000d0640 fffffbfff0b05e10 [ 28.803217] Call Trace: [ 28.805807] [] ? debug_object_active_state+0x420/0x420 [ 28.812736] [] free_pages_prepare+0x4a9/0xb30 [ 28.818905] [] __free_pages_ok+0x1c/0xbd0 [ 28.824712] [] free_compound_page+0x5e/0x70 [ 28.830689] [] __put_compound_page+0xa1/0xf0 [ 28.836748] [] put_compound_page+0xdb/0xb80 [ 28.842727] [] put_page+0x3d/0x110 [ 28.847922] [] khugepaged+0x35b/0x2ac0 [ 28.853472] [] ? set_huge_zero_page.isra.52.part.53+0x100/0x100 [ 28.861186] [] ? prepare_to_wait_event+0x420/0x420 [ 28.867768] [] ? __kthread_parkme+0x164/0x230 [ 28.873912] [] kthread+0x268/0x300 [ 28.879107] [] ? set_huge_zero_page.isra.52.part.53+0x100/0x100 [ 28.887913] [] ? kthread_create_on_node+0x400/0x400 [ 28.894588] [] ? kthread_create_on_node+0x400/0x400 [ 28.901262] [] ret_from_fork+0x3f/0x70 [ 28.906806] [] ? kthread_create_on_node+0x400/0x400 [ 28.913462] Code: 48 c7 c6 40 ea 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 [ 28.940908] RIP [] debug_check_no_obj_freed+0x1a8/0x9b0 [ 28.948057] RSP [ 28.951672] ---[ end trace 41c9caf2076fac65 ]--- [ 28.956418] Kernel panic - not syncing: Fatal exception [ 29.293449] PANIC: double fault, error_code: 0x0 [ 29.298242] CPU: 1 PID: 3314 Comm: syzkaller122763 Tainted: G D 4.4.111-g1849cd3 #19 [ 29.307223] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.316561] task: ffff8801d0e1c740 task.stack: ffff8801d0b68000 [ 29.322596] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 29.331460] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 29.336880] RAX: ffff8801d0e1c740 RBX: ffffea000742bf00 RCX: ffffffff8148f980 [ 29.344125] RDX: 0000000000000000 RSI: ffffffff838a8360 RDI: ffffea000742bf00 [ 29.351370] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 29.358615] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 29.365858] R13: ffffffff838a8360 R14: 0000000000000000 R15: 0000000000000000 [ 29.373103] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 29.381312] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 29.387168] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 29.394587] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.401833] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.409088] Stack: [ 29.411207] [ 29.412809] Call Trace: [ 29.415361] [ 29.417391] 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 61 06 ed ff 48 8d 7b 10 48 b8 00 00 00 00 00 fc ff df 48 89 [ 30.075324] Shutting down cpus with NMI [ 30.079730] Dumping ftrace buffer: [ 30.083240] (ftrace buffer empty) [ 30.086920] Kernel Offset: disabled [ 30.090519] Rebooting in 86400 seconds..