[ 17.645401] 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: [ 21.176588] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 21.447169] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 22.369973] random: sshd: uninitialized urandom read (32 bytes read, 96 bits of entropy available) [ 23.668455] random: sshd: uninitialized urandom read (32 bytes read, 101 bits of entropy available) Warning: Permanently added '10.128.0.11' (ECDSA) to the list of known hosts. [ 29.039259] random: sshd: uninitialized urandom read (32 bytes read, 107 bits of entropy available) executing program [ 29.139820] ================================================================== [ 29.147480] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 29.154822] Read of size 8 at addr ffff8800b4c9afb8 by task syzkaller971460/3317 [ 29.162673] [ 29.164276] CPU: 0 PID: 3317 Comm: syzkaller971460 Not tainted 4.4.112-gca0ebb4 #22 [ 29.173085] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.182428] 0000000000000000 5dc4fcea778e98e8 ffff8801d117f850 ffffffff81d056fd [ 29.190421] ffffea0002d32680 ffff8800b4c9afb8 0000000000000000 ffff8800b4c9afb8 [ 29.198410] 0000000000000000 ffff8801d117f888 ffffffff814fd953 ffff8800b4c9afb8 [ 29.206390] Call Trace: [ 29.208957] [] dump_stack+0xc1/0x124 [ 29.214567] [] print_address_description+0x73/0x260 [ 29.221818] [] kasan_report+0x285/0x370 [ 29.227432] [] ? __lock_acquire+0x387e/0x4b50 [ 29.235059] [] __asan_report_load8_noabort+0x14/0x20 [ 29.241789] [] __lock_acquire+0x387e/0x4b50 [ 29.248582] [] ? __lock_acquire+0xb5f/0x4b50 [ 29.255768] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 29.262760] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 29.269607] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 29.277382] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 29.284378] [] lock_acquire+0x15e/0x460 [ 29.290827] [] ? remove_wait_queue+0x14/0x40 [ 29.296867] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 29.303959] [] ? remove_wait_queue+0x14/0x40 [ 29.310783] [] remove_wait_queue+0x14/0x40 [ 29.316648] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 29.323653] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 29.330916] [] ? ep_free+0x1c0/0x1c0 [ 29.336701] [] ep_free+0x93/0x1c0 [ 29.342247] [] ? ep_free+0x1c0/0x1c0 [ 29.348915] [] ep_eventpoll_release+0x44/0x60 [ 29.355511] [] __fput+0x233/0x6d0 [ 29.360613] [] ____fput+0x15/0x20 [ 29.365734] [] task_work_run+0x104/0x180 [ 29.371467] [] do_exit+0x871/0x2a20 [ 29.376775] [] ? handle_mm_fault+0x192d/0x3190 [ 29.384427] [] ? handle_mm_fault+0x3f2/0x3190 [ 29.391139] [] ? release_task+0x1240/0x1240 [ 29.397127] [] do_group_exit+0x108/0x320 [ 29.402930] [] SyS_exit_group+0x1d/0x20 [ 29.408538] [] ? do_group_exit+0x320/0x320 [ 29.414406] [] do_fast_syscall_32+0x314/0x890 [ 29.420883] [] sysenter_flags_fixed+0xd/0x17 [ 29.427617] [ 29.430008] Allocated by task 3317: [ 29.435503] [] save_stack_trace+0x26/0x50 [ 29.442984] [] save_stack+0x43/0xd0 [ 29.449409] [] kasan_kmalloc+0xad/0xe0 [ 29.455048] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 29.461639] [] binder_get_thread+0x181/0x7a0 [ 29.468761] [] binder_poll+0x4a/0x210 [ 29.474313] [] SyS_epoll_ctl+0x10b1/0x2050 [ 29.480295] [] do_fast_syscall_32+0x314/0x890 [ 29.486540] [] sysenter_flags_fixed+0xd/0x17 [ 29.493740] [ 29.495357] Freed by task 3317: [ 29.500481] [] save_stack_trace+0x26/0x50 [ 29.508218] [] save_stack+0x43/0xd0 [ 29.513589] [] kasan_slab_free+0x72/0xc0 [ 29.519397] [] kfree+0xfc/0x300 [ 29.524603] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 29.531651] [] binder_thread_release+0x27d/0x540 [ 29.538678] [] binder_ioctl+0xb94/0x12e0 [ 29.544770] [] compat_SyS_ioctl+0x28a/0x2540 [ 29.550922] [] do_fast_syscall_32+0x314/0x890 [ 29.557868] [] sysenter_flags_fixed+0xd/0x17 [ 29.564031] [ 29.565637] The buggy address belongs to the object at ffff8800b4c9af00 [ 29.565637] which belongs to the cache kmalloc-512 of size 512 [ 29.578888] The buggy address is located 184 bytes inside of [ 29.578888] 512-byte region [ffff8800b4c9af00, ffff8800b4c9b100) [ 29.590738] The buggy address belongs to the page: [ 31.280495] PANIC: double fault, error_code: 0x0 [ 31.286553] CPU: 0 PID: 3317 Comm: syzkaller971460 Not tainted 4.4.112-gca0ebb4 #22 [ 31.294670] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.304097] task: ffff8801d2335f00 task.stack: ffff8801d1178000 [ 31.310689] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 31.320406] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 31.327960] RAX: ffff8801d2335f00 RBX: ffffea0002d32680 RCX: ffffffff8148fea0 [ 31.335936] RDX: 0000000000000000 RSI: ffffffff838a8620 RDI: ffffea0002d32680 [ 31.344248] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 31.351735] R10: 0000000000000002 R11: fffffbfff0ad7a1e R12: 0000000000000000 [ 31.359077] R13: ffffffff838a8620 R14: 0000000000000000 R15: 0000000000000000 [ 31.366389] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 31.374614] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 31.380482] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 31.387734] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 31.395591] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 31.403703] Stack: [ 31.405826] [ 31.407426] Call Trace: [ 31.409980] [ 31.412016] 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 [ 31.441158] Kernel panic - not syncing: Machine halted. [ 31.446507] CPU: 0 PID: 3317 Comm: syzkaller971460 Not tainted 4.4.112-gca0ebb4 #22 [ 31.454275] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.465523] 0000000000000000 5dc4fcea778e98e8 ffff8801db20ce38 ffffffff81d056fd [ 31.474731] ffffffff83836a60 ffff8801db20cf10 ffffffff83808040 ffff880100000000 [ 31.482989] 0000000000000000 ffff8801db20cf00 ffffffff81419dca 0000000041b58ab3 [ 31.491235] Call Trace: [ 31.494572] <#DF> [] dump_stack+0xc1/0x124 [ 31.502059] [] panic+0x1aa/0x388 [ 31.507052] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 31.513965] [] ? vprintk_emit+0x242/0x850 [ 31.519739] [] ? dump_page_badflags+0x2f/0x250 [ 31.525967] [] ? vprintk_emit+0x242/0x850 [ 31.531743] [] df_debug+0x2d/0x30 [ 31.536823] [] do_double_fault+0x10b/0x210 [ 31.542700] [] double_fault+0x2d/0x40 [ 31.548132] [] ? dump_page_badflags+0x180/0x250 [ 31.554442] [] ? dump_page_badflags+0x1a/0x250 [ 31.560655] <> [ 31.564508] Dumping ftrace buffer: [ 31.568329] (ftrace buffer empty) [ 31.572027] Kernel Offset: disabled [ 31.575630] Rebooting in 86400 seconds..