[ 17.074186] random: sshd: uninitialized urandom read (32 bytes read, 32 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: [ 21.731569] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 22.091733] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 23.056883] random: sshd: uninitialized urandom read (32 bytes read, 114 bits of entropy available) [ 23.223909] random: sshd: uninitialized urandom read (32 bytes read, 118 bits of entropy available) Warning: Permanently added '10.128.0.6' (ECDSA) to the list of known hosts. [ 28.609585] random: sshd: uninitialized urandom read (32 bytes read, 124 bits of entropy available) executing program [ 28.712659] ================================================================== [ 28.720080] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 28.726720] Read of size 8 at addr ffff8800b4a040b8 by task syzkaller720760/3325 [ 28.734221] [ 28.735820] CPU: 1 PID: 3325 Comm: syzkaller720760 Not tainted 4.4.113-ge70c132 #27 [ 28.743597] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.752926] 0000000000000000 3645c299dd96d325 ffff8801d0577870 ffffffff81d0278d [ 28.760916] ffffea0002d28100 ffff8800b4a040b8 0000000000000000 ffff8800b4a040b8 [ 28.768876] 0000000000000000 ffff8801d05778a8 ffffffff814fd053 ffff8800b4a040b8 [ 28.776840] Call Trace: [ 28.779403] [] dump_stack+0xc1/0x124 [ 28.784737] [] print_address_description+0x73/0x260 [ 28.791371] [] kasan_report+0x285/0x370 [ 28.796975] [] ? __lock_acquire+0x387e/0x4b50 [ 28.803094] [] __asan_report_load8_noabort+0x14/0x20 [ 28.809839] [] __lock_acquire+0x387e/0x4b50 [ 28.815791] [] ? __lock_acquire+0xb5f/0x4b50 [ 28.821834] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.828838] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 28.835656] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.843358] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.850361] [] lock_acquire+0x15e/0x460 [ 28.855975] [] ? remove_wait_queue+0x14/0x40 [ 28.862030] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 28.868356] [] ? remove_wait_queue+0x14/0x40 [ 28.874405] [] remove_wait_queue+0x14/0x40 [ 28.880274] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 28.887258] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 28.894506] [] ? ep_free+0x1c0/0x1c0 [ 28.899847] [] ep_free+0x93/0x1c0 [ 28.904927] [] ? ep_free+0x1c0/0x1c0 [ 28.910267] [] ep_eventpoll_release+0x44/0x60 [ 28.916383] [] __fput+0x233/0x6d0 [ 28.921453] [] ____fput+0x15/0x20 [ 28.926526] [] task_work_run+0x104/0x180 [ 28.932216] [] do_exit+0x82a/0x2a10 [ 28.937463] [] ? release_task+0x1240/0x1240 [ 28.943411] [] do_group_exit+0x108/0x320 [ 28.949095] [] SyS_exit_group+0x1d/0x20 [ 28.954686] [] ? do_group_exit+0x320/0x320 [ 28.960546] [] do_fast_syscall_32+0x314/0x890 [ 28.966671] [] sysenter_flags_fixed+0xd/0x17 [ 28.972696] [ 28.974294] Allocated by task 3325: [ 28.977972] [] save_stack_trace+0x26/0x50 [ 28.983862] [] save_stack+0x43/0xd0 [ 28.989244] [] kasan_kmalloc+0xad/0xe0 [ 28.994864] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 29.001450] [] binder_get_thread+0x15d/0x750 [ 29.007616] [] binder_poll+0x4a/0x210 [ 29.013154] [] SyS_epoll_ctl+0x10b1/0x2040 [ 29.019139] [] do_fast_syscall_32+0x314/0x890 [ 29.025388] [] sysenter_flags_fixed+0xd/0x17 [ 29.031544] [ 29.033154] Freed by task 3325: [ 29.036407] [] save_stack_trace+0x26/0x50 [ 29.042308] [] save_stack+0x43/0xd0 [ 29.047702] [] kasan_slab_free+0x72/0xc0 [ 29.053519] [] kfree+0xfc/0x300 [ 29.058563] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 29.065346] [] binder_thread_release+0x27d/0x540 [ 29.071848] [] binder_ioctl+0xb94/0x12e0 [ 29.077661] [] compat_SyS_ioctl+0x28a/0x2540 [ 29.083816] [] do_fast_syscall_32+0x314/0x890 [ 29.090055] [] sysenter_flags_fixed+0xd/0x17 [ 29.096222] [ 29.097822] The buggy address belongs to the object at ffff8800b4a04000 [ 29.097822] which belongs to the cache kmalloc-512 of size 512 [ 29.110461] The buggy address is located 184 bytes inside of [ 29.110461] 512-byte region [ffff8800b4a04000, ffff8800b4a04200) [ 29.122316] The buggy address belongs to the page: [ 30.680989] PANIC: double fault, error_code: 0x0 [ 30.685781] CPU: 1 PID: 3325 Comm: syzkaller720760 Not tainted 4.4.113-ge70c132 #27 [ 30.693551] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.702880] task: ffff8800b5b197c0 task.stack: ffff8801d0570000 [ 30.708906] RIP: 0010:[] [] dump_page_badflags+0x8/0x250 [ 30.717683] RSP: 0018:ffff880100000000 EFLAGS: 00010046 [ 30.723100] RAX: ffff8800b5b197c0 RBX: ffffea0002d28100 RCX: ffffffff8148f8d0 [ 30.730343] RDX: 0000000000000000 RSI: ffffffff838a8de0 RDI: ffffea0002d28100 [ 30.737583] RBP: ffff880100000010 R08: 0000000000000001 R09: 0000000000000000 [ 30.744822] R10: 0000000000000002 R11: fffffbfff0ad7e26 R12: 0000000000000000 [ 30.752064] R13: ffffffff838a8de0 R14: 0000000000000000 R15: 0000000000000000 [ 30.759317] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 30.767519] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 30.773380] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 30.780645] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 30.787911] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 30.795168] Stack: [ 30.797288] [ 30.798883] Call Trace: [ 30.801435] [ 30.803476] 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 [ 30.830460] Kernel panic - not syncing: Machine halted. [ 30.835799] CPU: 1 PID: 3325 Comm: syzkaller720760 Not tainted 4.4.113-ge70c132 #27 [ 30.843575] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.852904] 0000000000000000 3645c299dd96d325 ffff8801db30ce38 ffffffff81d0278d [ 30.860883] ffffffff83837200 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 30.868872] 0000000000000000 ffff8801db30cf00 ffffffff81419b6a 0000000041b58ab3 [ 30.876868] Call Trace: [ 30.879432] <#DF> [] dump_stack+0xc1/0x124 [ 30.885535] [] panic+0x1aa/0x388 [ 30.890528] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 30.897444] [] ? vprintk_emit+0x242/0x850 [ 30.903213] [] ? dump_page_badflags+0x1d/0x250 [ 30.909425] [] ? vprintk_emit+0x242/0x850 [ 30.915203] [] df_debug+0x2d/0x30 [ 30.920277] [] do_double_fault+0x10b/0x210 [ 30.926137] [] double_fault+0x2d/0x40 [ 30.931558] [] ? dump_page_badflags+0x180/0x250 [ 30.937858] [] ? dump_page_badflags+0x8/0x250 [ 30.943981] <> [ 30.947418] Dumping ftrace buffer: [ 30.951230] (ftrace buffer empty) [ 30.954918] Kernel Offset: disabled [ 30.958526] Rebooting in 86400 seconds..