[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.621725] 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: [ 19.903502] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 20.317633] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 21.215232] random: sshd: uninitialized urandom read (32 bytes read, 108 bits of entropy available) [ 21.383105] random: sshd: uninitialized urandom read (32 bytes read, 112 bits of entropy available) Warning: Permanently added '10.128.0.37' (ECDSA) to the list of known hosts. [ 26.772641] random: sshd: uninitialized urandom read (32 bytes read, 117 bits of entropy available) executing program [ 26.893911] ================================================================== [ 26.901308] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 26.907941] Read of size 8 at addr ffff8801d164cab8 by task syzkaller949949/3325 [ 26.915436] [ 26.917032] CPU: 1 PID: 3325 Comm: syzkaller949949 Not tainted 4.4.110-g618a510 #15 [ 26.924786] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.934104] 0000000000000000 ba2ececa89d03293 ffff8801d04a7850 ffffffff81d04e3d [ 26.942061] ffffea0007459300 ffff8801d164cab8 0000000000000000 ffff8801d164cab8 [ 26.950009] 0000000000000000 ffff8801d04a7888 ffffffff814fd1f3 ffff8801d164cab8 [ 26.957959] Call Trace: [ 26.960523] [] dump_stack+0xc1/0x124 [ 26.965854] [] print_address_description+0x73/0x260 [ 26.972487] [] kasan_report+0x285/0x370 [ 26.978082] [] ? __lock_acquire+0x387e/0x4b50 [ 26.984199] [] __asan_report_load8_noabort+0x14/0x20 [ 26.990919] [] __lock_acquire+0x387e/0x4b50 [ 26.996854] [] ? __lock_acquire+0xb5f/0x4b50 [ 27.002895] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.009878] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 27.016687] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.023692] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.030674] [] lock_acquire+0x15e/0x460 [ 27.036266] [] ? remove_wait_queue+0x14/0x40 [ 27.042289] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 27.048575] [] ? remove_wait_queue+0x14/0x40 [ 27.054603] [] remove_wait_queue+0x14/0x40 [ 27.060460] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 27.067438] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 27.074676] [] ? ep_free+0x1c0/0x1c0 [ 27.080007] [] ep_free+0x93/0x1c0 [ 27.085075] [] ? ep_free+0x1c0/0x1c0 [ 27.090404] [] ep_eventpoll_release+0x44/0x60 [ 27.096516] [] __fput+0x233/0x6d0 [ 27.101585] [] ____fput+0x15/0x20 [ 27.106658] [] task_work_run+0x104/0x180 [ 27.112335] [] do_exit+0x871/0x2a20 [ 27.117578] [] ? handle_mm_fault+0x192d/0x3190 [ 27.123773] [] ? handle_mm_fault+0x3f2/0x3190 [ 27.129883] [] ? release_task+0x1240/0x1240 [ 27.135831] [] do_group_exit+0x108/0x320 [ 27.141511] [] SyS_exit_group+0x1d/0x20 [ 27.147102] [] ? do_group_exit+0x320/0x320 [ 27.152953] [] do_fast_syscall_32+0x314/0x890 [ 27.159072] [] sysenter_flags_fixed+0xd/0x17 [ 27.165107] [ 27.166700] Allocated by task 3325: [ 27.170290] [] save_stack_trace+0x26/0x50 [ 27.176174] [] save_stack+0x43/0xd0 [ 27.181554] [] kasan_kmalloc+0xad/0xe0 [ 27.187177] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 27.193745] [] binder_get_thread+0x181/0x7a0 [ 27.199884] [] binder_poll+0x4a/0x210 [ 27.205410] [] SyS_epoll_ctl+0x10b1/0x2050 [ 27.211390] [] do_fast_syscall_32+0x314/0x890 [ 27.217617] [] sysenter_flags_fixed+0xd/0x17 [ 27.223751] [ 27.225343] Freed by task 3325: [ 27.228583] [] save_stack_trace+0x26/0x50 [ 27.234463] [] save_stack+0x43/0xd0 [ 27.239814] [] kasan_slab_free+0x72/0xc0 [ 27.245603] [] kfree+0xfc/0x300 [ 27.250621] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 27.257391] [] binder_thread_release+0x27d/0x540 [ 27.263882] [] binder_ioctl+0xb94/0x12e0 [ 27.269678] [] compat_SyS_ioctl+0x28a/0x2540 [ 27.275826] [] do_fast_syscall_32+0x314/0x890 [ 27.282054] [] sysenter_flags_fixed+0xd/0x17 [ 27.288193] [ 27.289785] The buggy address belongs to the object at ffff8801d164ca00 [ 27.289785] which belongs to the cache kmalloc-512 of size 512 [ 27.302403] The buggy address is located 184 bytes inside of [ 27.302403] 512-byte region [ffff8801d164ca00, ffff8801d164cc00) [ 27.314246] The buggy address belongs to the page: [ 28.839193] PANIC: double fault, error_code: 0x0 [ 28.843966] CPU: 1 PID: 3325 Comm: syzkaller949949 Not tainted 4.4.110-g618a510 #15 [ 28.851725] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.861046] task: ffff8800b4548000 task.stack: ffff8801d04a0000 [ 28.867073] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 28.875910] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 28.881328] RAX: ffff8800b4548000 RBX: ffffea0007459300 RCX: ffffffff8148f740 [ 28.888565] RDX: 0000000000000000 RSI: ffffffff838a8320 RDI: ffffea0007459300 [ 28.895802] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 28.903044] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 28.910282] R13: ffffffff838a8320 R14: 0000000000000000 R15: 0000000000000000 [ 28.917526] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 28.925727] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 28.931584] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 28.938829] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 28.946069] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 28.953304] Stack: [ 28.955423] [ 28.957023] Call Trace: [ 28.959570] [ 28.961598] 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 [ 28.988182] Kernel panic - not syncing: Machine halted. [ 28.993520] CPU: 1 PID: 3325 Comm: syzkaller949949 Not tainted 4.4.110-g618a510 #15 [ 29.001276] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.010602] 0000000000000000 ba2ececa89d03293 ffff8801db30ce38 ffffffff81d04e3d [ 29.018583] ffffffff838367c0 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 29.026539] 0000000000000000 ffff8801db30cf00 ffffffff814197fa 0000000041b58ab3 [ 29.034482] Call Trace: [ 29.037034] <#DF> [] dump_stack+0xc1/0x124 [ 29.043090] [] panic+0x1aa/0x388 [ 29.048073] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 29.054981] [] ? vprintk_emit+0x242/0x850 [ 29.060752] [] ? dump_page_badflags+0x2f/0x250 [ 29.066952] [] ? vprintk_emit+0x242/0x850 [ 29.072715] [] df_debug+0x2d/0x30 [ 29.077793] [] do_double_fault+0x10b/0x210 [ 29.083649] [] double_fault+0x2d/0x40 [ 29.089079] [] ? dump_page_badflags+0x180/0x250 [ 29.095367] [] ? dump_page_badflags+0x1a/0x250 [ 29.101566] <> [ 29.105021] Dumping ftrace buffer: [ 29.108812] (ftrace buffer empty) [ 29.112500] Kernel Offset: disabled [ 29.116093] Rebooting in 86400 seconds..