[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.544175] 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: [ 21.911795] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available) [ 22.413164] random: sshd: uninitialized urandom read (32 bytes read, 40 bits of entropy available) [ 23.186990] random: sshd: uninitialized urandom read (32 bytes read, 84 bits of entropy available) [ 23.356208] random: sshd: uninitialized urandom read (32 bytes read, 89 bits of entropy available) Warning: Permanently added '10.128.0.58' (ECDSA) to the list of known hosts. [ 29.187078] random: sshd: uninitialized urandom read (32 bytes read, 96 bits of entropy available) executing program [ 29.283090] ================================================================== [ 29.290507] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 29.297143] Read of size 8 at addr ffff8801d06c34b8 by task syzkaller420901/3332 [ 29.304643] [ 29.306256] CPU: 0 PID: 3332 Comm: syzkaller420901 Not tainted 4.4.111-gf851888 #16 [ 29.314018] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.323345] 0000000000000000 20fe0b3e6a7ba0af ffff8801d0bdf850 ffffffff81d0507d [ 29.331300] ffffea000741b080 ffff8801d06c34b8 0000000000000000 ffff8801d06c34b8 [ 29.339257] 0000000000000000 ffff8801d0bdf888 ffffffff814fd433 ffff8801d06c34b8 [ 29.347205] Call Trace: [ 29.349763] [] dump_stack+0xc1/0x124 [ 29.355096] [] print_address_description+0x73/0x260 [ 29.361742] [] kasan_report+0x285/0x370 [ 29.367333] [] ? __lock_acquire+0x387e/0x4b50 [ 29.373446] [] __asan_report_load8_noabort+0x14/0x20 [ 29.380168] [] __lock_acquire+0x387e/0x4b50 [ 29.386107] [] ? __lock_acquire+0xb5f/0x4b50 [ 29.392133] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 29.399113] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 29.405920] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 29.412901] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 29.419886] [] lock_acquire+0x15e/0x460 [ 29.425480] [] ? remove_wait_queue+0x14/0x40 [ 29.431513] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 29.437801] [] ? remove_wait_queue+0x14/0x40 [ 29.443825] [] remove_wait_queue+0x14/0x40 [ 29.449680] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 29.456659] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 29.463899] [] ? ep_free+0x1c0/0x1c0 [ 29.469226] [] ep_free+0x93/0x1c0 [ 29.474293] [] ? ep_free+0x1c0/0x1c0 [ 29.479625] [] ep_eventpoll_release+0x44/0x60 [ 29.485738] [] __fput+0x233/0x6d0 [ 29.490807] [] ____fput+0x15/0x20 [ 29.495879] [] task_work_run+0x104/0x180 [ 29.501559] [] do_exit+0x871/0x2a20 [ 29.506803] [] ? handle_mm_fault+0x192d/0x3190 [ 29.513001] [] ? handle_mm_fault+0x3f2/0x3190 [ 29.519111] [] ? release_task+0x1240/0x1240 [ 29.525051] [] do_group_exit+0x108/0x320 [ 29.530740] [] SyS_exit_group+0x1d/0x20 [ 29.536328] [] ? do_group_exit+0x320/0x320 [ 29.542185] [] do_fast_syscall_32+0x314/0x890 [ 29.548298] [] sysenter_flags_fixed+0xd/0x17 [ 29.554320] [ 29.555915] Allocated by task 3332: [ 29.559504] [] save_stack_trace+0x26/0x50 [ 29.565390] [] save_stack+0x43/0xd0 [ 29.570746] [] kasan_kmalloc+0xad/0xe0 [ 29.576363] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 29.582936] [] binder_get_thread+0x181/0x7a0 [ 29.589088] [] binder_poll+0x4a/0x210 [ 29.594621] [] SyS_epoll_ctl+0x10b1/0x2050 [ 29.600587] [] do_fast_syscall_32+0x314/0x890 [ 29.606813] [] sysenter_flags_fixed+0xd/0x17 [ 29.612950] [ 29.614545] Freed by task 3332: [ 29.617785] [] save_stack_trace+0x26/0x50 [ 29.623665] [] save_stack+0x43/0xd0 [ 29.629021] [] kasan_slab_free+0x72/0xc0 [ 29.634806] [] kfree+0xfc/0x300 [ 29.639812] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 29.646573] [] binder_thread_release+0x27d/0x540 [ 29.653062] [] binder_ioctl+0xb94/0x12e0 [ 29.658852] [] compat_SyS_ioctl+0x28a/0x2540 [ 29.664989] [] do_fast_syscall_32+0x314/0x890 [ 29.671210] [] sysenter_flags_fixed+0xd/0x17 [ 29.677357] [ 29.678950] The buggy address belongs to the object at ffff8801d06c3400 [ 29.678950] which belongs to the cache kmalloc-512 of size 512 [ 29.691571] The buggy address is located 184 bytes inside of [ 29.691571] 512-byte region [ffff8801d06c3400, ffff8801d06c3600) [ 29.703416] The buggy address belongs to the page: [ 31.224752] PANIC: double fault, error_code: 0x0 [ 31.229543] CPU: 0 PID: 3332 Comm: syzkaller420901 Not tainted 4.4.111-gf851888 #16 [ 31.237307] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.246631] task: ffff8801d2020000 task.stack: ffff8801d0bd8000 [ 31.252653] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 31.261498] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 31.266912] RAX: ffff8801d2020000 RBX: ffffea000741b080 RCX: ffffffff8148f980 [ 31.274155] RDX: 0000000000000000 RSI: ffffffff838a83a0 RDI: ffffea000741b080 [ 31.281393] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 31.288629] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 31.295866] R13: ffffffff838a83a0 R14: 0000000000000000 R15: 0000000000000000 [ 31.303103] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 31.311294] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 31.317141] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 31.324377] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 31.331614] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 31.338848] Stack: [ 31.340961] [ 31.342564] Call Trace: [ 31.345113] [ 31.347137] 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 [ 31.373770] Kernel panic - not syncing: Machine halted. [ 31.379109] CPU: 0 PID: 3332 Comm: syzkaller420901 Not tainted 4.4.111-gf851888 #16 [ 31.386866] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.396191] 0000000000000000 20fe0b3e6a7ba0af ffff8801db20ce38 ffffffff81d0507d [ 31.404135] ffffffff838367c0 ffff8801db20cf10 ffffffff83808040 ffff880100000000 [ 31.412093] 0000000000000000 ffff8801db20cf00 ffffffff81419a3a 0000000041b58ab3 [ 31.420040] Call Trace: [ 31.422587] <#DF> [] dump_stack+0xc1/0x124 [ 31.428650] [] panic+0x1aa/0x388 [ 31.433635] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 31.440530] [] ? vprintk_emit+0x242/0x850 [ 31.446305] [] ? dump_page_badflags+0x2f/0x250 [ 31.452503] [] ? vprintk_emit+0x242/0x850 [ 31.458268] [] df_debug+0x2d/0x30 [ 31.463341] [] do_double_fault+0x10b/0x210 [ 31.469195] [] double_fault+0x2d/0x40 [ 31.474612] [] ? dump_page_badflags+0x180/0x250 [ 31.480898] [] ? dump_page_badflags+0x1a/0x250 [ 31.487092] <> [ 31.490492] Dumping ftrace buffer: [ 31.494285] (ftrace buffer empty) [ 31.497962] Kernel Offset: disabled [ 31.501557] Rebooting in 86400 seconds..