[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.331509] 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: [ 21.146474] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 21.565459] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 22.412330] random: sshd: uninitialized urandom read (32 bytes read, 102 bits of entropy available) [ 22.586674] random: sshd: uninitialized urandom read (32 bytes read, 108 bits of entropy available) Warning: Permanently added '10.128.0.21' (ECDSA) to the list of known hosts. [ 28.076560] random: sshd: uninitialized urandom read (32 bytes read, 114 bits of entropy available) executing program [ 28.171195] ================================================================== [ 28.178610] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 28.185254] Read of size 8 at addr ffff8800b522ad38 by task syzkaller150701/3325 [ 28.192760] [ 28.194364] CPU: 1 PID: 3325 Comm: syzkaller150701 Not tainted 4.4.111-gf851888 #16 [ 28.202127] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.211462] 0000000000000000 3c6950de87f3f1ff ffff8801d0a7f850 ffffffff81d0507d [ 28.219418] ffffea0002d48a80 ffff8800b522ad38 0000000000000000 ffff8800b522ad38 [ 28.227360] 0000000000000000 ffff8801d0a7f888 ffffffff814fd433 ffff8800b522ad38 [ 28.235306] Call Trace: [ 28.237863] [] dump_stack+0xc1/0x124 [ 28.243194] [] print_address_description+0x73/0x260 [ 28.249825] [] kasan_report+0x285/0x370 [ 28.255423] [] ? __lock_acquire+0x387e/0x4b50 [ 28.261537] [] __asan_report_load8_noabort+0x14/0x20 [ 28.268252] [] __lock_acquire+0x387e/0x4b50 [ 28.274185] [] ? __lock_acquire+0xb5f/0x4b50 [ 28.280220] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.287212] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 28.294019] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.301009] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.307984] [] lock_acquire+0x15e/0x460 [ 28.313574] [] ? remove_wait_queue+0x14/0x40 [ 28.319623] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 28.325905] [] ? remove_wait_queue+0x14/0x40 [ 28.331928] [] remove_wait_queue+0x14/0x40 [ 28.337779] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 28.344759] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 28.352002] [] ? ep_free+0x1c0/0x1c0 [ 28.357328] [] ep_free+0x93/0x1c0 [ 28.362396] [] ? ep_free+0x1c0/0x1c0 [ 28.367723] [] ep_eventpoll_release+0x44/0x60 [ 28.373831] [] __fput+0x233/0x6d0 [ 28.378895] [] ____fput+0x15/0x20 [ 28.383963] [] task_work_run+0x104/0x180 [ 28.389647] [] do_exit+0x871/0x2a20 [ 28.394891] [] ? handle_mm_fault+0x192d/0x3190 [ 28.401092] [] ? handle_mm_fault+0x3f2/0x3190 [ 28.407225] [] ? release_task+0x1240/0x1240 [ 28.413174] [] do_group_exit+0x108/0x320 [ 28.418849] [] SyS_exit_group+0x1d/0x20 [ 28.424435] [] ? do_group_exit+0x320/0x320 [ 28.430285] [] do_fast_syscall_32+0x314/0x890 [ 28.436396] [] sysenter_flags_fixed+0xd/0x17 [ 28.442416] [ 28.444008] Allocated by task 3325: [ 28.447597] [] save_stack_trace+0x26/0x50 [ 28.453472] [] save_stack+0x43/0xd0 [ 28.458831] [] kasan_kmalloc+0xad/0xe0 [ 28.464446] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 28.471014] [] binder_get_thread+0x181/0x7a0 [ 28.477152] [] binder_poll+0x4a/0x210 [ 28.482679] [] SyS_epoll_ctl+0x10b1/0x2050 [ 28.488644] [] do_fast_syscall_32+0x314/0x890 [ 28.494864] [] sysenter_flags_fixed+0xd/0x17 [ 28.501006] [ 28.502601] Freed by task 3325: [ 28.505840] [] save_stack_trace+0x26/0x50 [ 28.511715] [] save_stack+0x43/0xd0 [ 28.517067] [] kasan_slab_free+0x72/0xc0 [ 28.522866] [] kfree+0xfc/0x300 [ 28.527869] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 28.534610] [] binder_thread_release+0x27d/0x540 [ 28.541099] [] binder_ioctl+0xb94/0x12e0 [ 28.546910] [] compat_SyS_ioctl+0x28a/0x2540 [ 28.553050] [] do_fast_syscall_32+0x314/0x890 [ 28.559275] [] sysenter_flags_fixed+0xd/0x17 [ 28.565415] [ 28.567007] The buggy address belongs to the object at ffff8800b522ac80 [ 28.567007] which belongs to the cache kmalloc-512 of size 512 [ 28.579632] The buggy address is located 184 bytes inside of [ 28.579632] 512-byte region [ffff8800b522ac80, ffff8800b522ae80) [ 28.591469] The buggy address belongs to the page: [ 30.122886] PANIC: double fault, error_code: 0x0 [ 30.127664] CPU: 1 PID: 3325 Comm: syzkaller150701 Not tainted 4.4.111-gf851888 #16 [ 30.135427] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.144755] task: ffff8800b52317c0 task.stack: ffff8801d0a78000 [ 30.150774] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 30.159607] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 30.165025] RAX: ffff8800b52317c0 RBX: ffffea0002d48a80 RCX: ffffffff8148f980 [ 30.172261] RDX: 0000000000000000 RSI: ffffffff838a83a0 RDI: ffffea0002d48a80 [ 30.179503] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 30.186746] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 30.193997] R13: ffffffff838a83a0 R14: 0000000000000000 R15: 0000000000000000 [ 30.201249] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 30.209458] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 30.215323] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 30.222579] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 30.229826] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 30.237065] Stack: [ 30.239193] [ 30.240786] Call Trace: [ 30.243331] [ 30.245357] 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 [ 30.271861] Kernel panic - not syncing: Machine halted. [ 30.277189] CPU: 1 PID: 3325 Comm: syzkaller150701 Not tainted 4.4.111-gf851888 #16 [ 30.284945] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.294261] 0000000000000000 3c6950de87f3f1ff ffff8801db30ce38 ffffffff81d0507d [ 30.302207] ffffffff838367c0 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 30.310150] 0000000000000000 ffff8801db30cf00 ffffffff81419a3a 0000000041b58ab3 [ 30.318101] Call Trace: [ 30.320649] <#DF> [] dump_stack+0xc1/0x124 [ 30.326710] [] panic+0x1aa/0x388 [ 30.331701] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 30.338599] [] ? vprintk_emit+0x242/0x850 [ 30.344368] [] ? dump_page_badflags+0x2f/0x250 [ 30.350563] [] ? vprintk_emit+0x242/0x850 [ 30.356413] [] df_debug+0x2d/0x30 [ 30.361483] [] do_double_fault+0x10b/0x210 [ 30.367340] [] double_fault+0x2d/0x40 [ 30.372761] [] ? dump_page_badflags+0x180/0x250 [ 30.379060] [] ? dump_page_badflags+0x1a/0x250 [ 30.385253] <> [ 30.388628] Dumping ftrace buffer: [ 30.392422] (ftrace buffer empty) [ 30.396098] Kernel Offset: disabled [ 30.399688] Rebooting in 86400 seconds..