[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.195256] random: sshd: uninitialized urandom read (32 bytes read, 33 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 19.706706] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available) [ 19.946424] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available) [ 20.749333] random: sshd: uninitialized urandom read (32 bytes read, 103 bits of entropy available) [ 20.926693] random: sshd: uninitialized urandom read (32 bytes read, 107 bits of entropy available) Warning: Permanently added '10.128.15.209' (ECDSA) to the list of known hosts. [ 26.295096] random: sshd: uninitialized urandom read (32 bytes read, 112 bits of entropy available) executing program [ 26.435219] ================================================================== [ 26.442619] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 26.449257] Read of size 8 at addr ffff8800b55d14b8 by task syzkaller889310/3316 [ 26.456752] [ 26.458354] CPU: 1 PID: 3316 Comm: syzkaller889310 Not tainted 4.4.111-g7902639 #18 [ 26.466118] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.475439] 0000000000000000 1a8bbceb656b673f ffff8801d085f850 ffffffff81d0509d [ 26.483410] ffffea0002d57400 ffff8800b55d14b8 0000000000000000 ffff8800b55d14b8 [ 26.491358] 0000000000000000 ffff8801d085f888 ffffffff814fd433 ffff8800b55d14b8 [ 26.499319] Call Trace: [ 26.501878] [] dump_stack+0xc1/0x124 [ 26.507214] [] print_address_description+0x73/0x260 [ 26.513846] [] kasan_report+0x285/0x370 [ 26.519434] [] ? __lock_acquire+0x387e/0x4b50 [ 26.525549] [] __asan_report_load8_noabort+0x14/0x20 [ 26.532268] [] __lock_acquire+0x387e/0x4b50 [ 26.538209] [] ? __lock_acquire+0xb5f/0x4b50 [ 26.544231] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 26.551213] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 26.558023] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 26.565009] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 26.571988] [] lock_acquire+0x15e/0x460 [ 26.577575] [] ? remove_wait_queue+0x14/0x40 [ 26.583600] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 26.589882] [] ? remove_wait_queue+0x14/0x40 [ 26.595904] [] remove_wait_queue+0x14/0x40 [ 26.601755] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 26.608737] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 26.615979] [] ? ep_free+0x1c0/0x1c0 [ 26.621308] [] ep_free+0x93/0x1c0 [ 26.626376] [] ? ep_free+0x1c0/0x1c0 [ 26.631707] [] ep_eventpoll_release+0x44/0x60 [ 26.637815] [] __fput+0x233/0x6d0 [ 26.642883] [] ____fput+0x15/0x20 [ 26.647952] [] task_work_run+0x104/0x180 [ 26.653627] [] do_exit+0x871/0x2a20 [ 26.658877] [] ? handle_mm_fault+0x192d/0x3190 [ 26.665082] [] ? handle_mm_fault+0x3f2/0x3190 [ 26.671192] [] ? release_task+0x1240/0x1240 [ 26.677136] [] do_group_exit+0x108/0x320 [ 26.682812] [] SyS_exit_group+0x1d/0x20 [ 26.688399] [] ? do_group_exit+0x320/0x320 [ 26.694250] [] do_fast_syscall_32+0x314/0x890 [ 26.700372] [] sysenter_flags_fixed+0xd/0x17 [ 26.706392] [ 26.707986] Allocated by task 3316: [ 26.711574] [] save_stack_trace+0x26/0x50 [ 26.717468] [] save_stack+0x43/0xd0 [ 26.722826] [] kasan_kmalloc+0xad/0xe0 [ 26.728442] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 26.735012] [] binder_get_thread+0x181/0x7a0 [ 26.741150] [] binder_poll+0x4a/0x210 [ 26.746679] [] SyS_epoll_ctl+0x10b1/0x2050 [ 26.752643] [] do_fast_syscall_32+0x314/0x890 [ 26.758872] [] sysenter_flags_fixed+0xd/0x17 [ 26.765028] [ 26.766622] Freed by task 3316: [ 26.769863] [] save_stack_trace+0x26/0x50 [ 26.775741] [] save_stack+0x43/0xd0 [ 26.781096] [] kasan_slab_free+0x72/0xc0 [ 26.786882] [] kfree+0xfc/0x300 [ 26.792847] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 26.799599] [] binder_thread_release+0x27d/0x540 [ 26.806089] [] binder_ioctl+0xb94/0x12e0 [ 26.811879] [] compat_SyS_ioctl+0x28a/0x2540 [ 26.818014] [] do_fast_syscall_32+0x314/0x890 [ 26.824244] [] sysenter_flags_fixed+0xd/0x17 [ 26.830383] [ 26.831977] The buggy address belongs to the object at ffff8800b55d1400 [ 26.831977] which belongs to the cache kmalloc-512 of size 512 [ 26.844603] The buggy address is located 184 bytes inside of [ 26.844603] 512-byte region [ffff8800b55d1400, ffff8800b55d1600) [ 26.856442] The buggy address belongs to the page: [ 28.361736] PANIC: double fault, error_code: 0x0 [ 28.366508] CPU: 1 PID: 3316 Comm: syzkaller889310 Not tainted 4.4.111-g7902639 #18 [ 28.374355] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.383679] task: ffff8800b57a4740 task.stack: ffff8801d0858000 [ 28.389699] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 28.398531] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 28.403949] RAX: ffff8800b57a4740 RBX: ffffea0002d57400 RCX: ffffffff8148f980 [ 28.411195] RDX: 0000000000000000 RSI: ffffffff838a8360 RDI: ffffea0002d57400 [ 28.418432] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 28.425673] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 28.432909] R13: ffffffff838a8360 R14: 0000000000000000 R15: 0000000000000000 [ 28.440161] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 28.448352] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 28.454198] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 28.461435] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 28.468671] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 28.475904] Stack: [ 28.478015] [ 28.479607] Call Trace: [ 28.482154] [ 28.484177] 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 [ 28.510785] Kernel panic - not syncing: Machine halted. [ 28.516114] CPU: 1 PID: 3316 Comm: syzkaller889310 Not tainted 4.4.111-g7902639 #18 [ 28.523880] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.533199] 0000000000000000 1a8bbceb656b673f ffff8801db30ce38 ffffffff81d0509d [ 28.541144] ffffffff838367c0 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 28.549091] 0000000000000000 ffff8801db30cf00 ffffffff81419a3a 0000000041b58ab3 [ 28.557033] Call Trace: [ 28.559583] <#DF> [] dump_stack+0xc1/0x124 [ 28.565650] [] panic+0x1aa/0x388 [ 28.570636] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 28.577533] [] ? vprintk_emit+0x242/0x850 [ 28.583297] [] ? dump_page_badflags+0x2f/0x250 [ 28.589503] [] ? vprintk_emit+0x242/0x850 [ 28.595271] [] df_debug+0x2d/0x30 [ 28.600348] [] do_double_fault+0x10b/0x210 [ 28.606205] [] double_fault+0x2d/0x40 [ 28.611635] [] ? dump_page_badflags+0x180/0x250 [ 28.617918] [] ? dump_page_badflags+0x1a/0x250 [ 28.624112] <> [ 28.627553] Dumping ftrace buffer: [ 28.631355] (ftrace buffer empty) [ 28.635030] Kernel Offset: disabled [ 28.638630] Rebooting in 86400 seconds..