[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.366862] 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: [ 21.471375] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 21.754123] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 22.643234] random: sshd: uninitialized urandom read (32 bytes read, 107 bits of entropy available) [ 22.824060] random: sshd: uninitialized urandom read (32 bytes read, 111 bits of entropy available) Warning: Permanently added '10.128.15.223' (ECDSA) to the list of known hosts. [ 28.211912] random: sshd: uninitialized urandom read (32 bytes read, 119 bits of entropy available) executing program [ 28.323918] ================================================================== [ 28.331313] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 28.337949] Read of size 8 at addr ffff8801cd3be5b8 by task syzkaller970994/3316 [ 28.345452] [ 28.347057] CPU: 1 PID: 3316 Comm: syzkaller970994 Not tainted 4.4.111-gc2f631b #20 [ 28.354824] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.364167] 0000000000000000 a4e346ce90e02fbc ffff8801cd397850 ffffffff81d0513d [ 28.372152] ffffea000734ef80 ffff8801cd3be5b8 0000000000000000 ffff8801cd3be5b8 [ 28.380128] 0000000000000000 ffff8801cd397888 ffffffff814fd433 ffff8801cd3be5b8 [ 28.388091] Call Trace: [ 28.390651] [] dump_stack+0xc1/0x124 [ 28.395988] [] print_address_description+0x73/0x260 [ 28.402622] [] kasan_report+0x285/0x370 [ 28.408212] [] ? __lock_acquire+0x387e/0x4b50 [ 28.414323] [] __asan_report_load8_noabort+0x14/0x20 [ 28.421042] [] __lock_acquire+0x387e/0x4b50 [ 28.426982] [] ? __lock_acquire+0xb5f/0x4b50 [ 28.433011] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.439991] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 28.446797] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.453778] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.460758] [] lock_acquire+0x15e/0x460 [ 28.466359] [] ? remove_wait_queue+0x14/0x40 [ 28.472387] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 28.478672] [] ? remove_wait_queue+0x14/0x40 [ 28.484697] [] remove_wait_queue+0x14/0x40 [ 28.490549] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 28.497528] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 28.504769] [] ? ep_free+0x1c0/0x1c0 [ 28.510111] [] ep_free+0x93/0x1c0 [ 28.515183] [] ? ep_free+0x1c0/0x1c0 [ 28.520518] [] ep_eventpoll_release+0x44/0x60 [ 28.526637] [] __fput+0x233/0x6d0 [ 28.531709] [] ____fput+0x15/0x20 [ 28.536785] [] task_work_run+0x104/0x180 [ 28.542464] [] do_exit+0x871/0x2a20 [ 28.547711] [] ? handle_mm_fault+0x192d/0x3190 [ 28.553908] [] ? handle_mm_fault+0x3f2/0x3190 [ 28.560022] [] ? release_task+0x1240/0x1240 [ 28.565960] [] do_group_exit+0x108/0x320 [ 28.571646] [] SyS_exit_group+0x1d/0x20 [ 28.577237] [] ? do_group_exit+0x320/0x320 [ 28.583090] [] do_fast_syscall_32+0x314/0x890 [ 28.589210] [] sysenter_flags_fixed+0xd/0x17 [ 28.595240] [ 28.596836] Allocated by task 3316: [ 28.600427] [] save_stack_trace+0x26/0x50 [ 28.606319] [] save_stack+0x43/0xd0 [ 28.611683] [] kasan_kmalloc+0xad/0xe0 [ 28.617303] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 28.623880] [] binder_get_thread+0x181/0x7a0 [ 28.630040] [] binder_poll+0x4a/0x210 [ 28.635586] [] SyS_epoll_ctl+0x10b1/0x2050 [ 28.641558] [] do_fast_syscall_32+0x314/0x890 [ 28.647787] [] sysenter_flags_fixed+0xd/0x17 [ 28.653938] [ 28.655541] Freed by task 3316: [ 28.658794] [] save_stack_trace+0x26/0x50 [ 28.664683] [] save_stack+0x43/0xd0 [ 28.670048] [] kasan_slab_free+0x72/0xc0 [ 28.675856] [] kfree+0xfc/0x300 [ 28.680876] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 28.687628] [] binder_thread_release+0x27d/0x540 [ 28.694122] [] binder_ioctl+0xb94/0x12e0 [ 28.699915] [] compat_SyS_ioctl+0x28a/0x2540 [ 28.706074] [] do_fast_syscall_32+0x314/0x890 [ 28.712301] [] sysenter_flags_fixed+0xd/0x17 [ 28.718445] [ 28.720042] The buggy address belongs to the object at ffff8801cd3be500 [ 28.720042] which belongs to the cache kmalloc-512 of size 512 [ 28.732666] The buggy address is located 184 bytes inside of [ 28.732666] 512-byte region [ffff8801cd3be500, ffff8801cd3be700) [ 28.744507] The buggy address belongs to the page: [ 30.183662] PANIC: double fault, error_code: 0x0 [ 30.188433] CPU: 1 PID: 3316 Comm: syzkaller970994 Not tainted 4.4.111-gc2f631b #20 [ 30.196194] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.206096] task: ffff8801d135df00 task.stack: ffff8801cd390000 [ 30.212120] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 30.220958] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 30.226381] RAX: ffff8801d135df00 RBX: ffffea000734ef80 RCX: ffffffff8148f980 [ 30.233618] RDX: 0000000000000000 RSI: ffffffff838a8360 RDI: ffffea000734ef80 [ 30.240864] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 30.248108] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 30.255353] R13: ffffffff838a8360 R14: 0000000000000000 R15: 0000000000000000 [ 30.262594] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 30.270785] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 30.276634] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 30.283876] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 30.291125] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 30.298359] Stack: [ 30.300474] [ 30.302067] Call Trace: [ 30.304618] [ 30.306643] 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 [ 30.333435] Kernel panic - not syncing: Machine halted. [ 30.338766] CPU: 1 PID: 3316 Comm: syzkaller970994 Not tainted 4.4.111-gc2f631b #20 [ 30.346524] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.355842] 0000000000000000 a4e346ce90e02fbc ffff8801db30ce38 ffffffff81d0513d [ 30.363797] ffffffff838367c0 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 30.371759] 0000000000000000 ffff8801db30cf00 ffffffff81419a3a 0000000041b58ab3 [ 30.379717] Call Trace: [ 30.382265] <#DF> [] dump_stack+0xc1/0x124 [ 30.388332] [] panic+0x1aa/0x388 [ 30.393319] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 30.400219] [] ? vprintk_emit+0x242/0x850 [ 30.405984] [] ? dump_page_badflags+0x2f/0x250 [ 30.412182] [] ? vprintk_emit+0x242/0x850 [ 30.417952] [] df_debug+0x2d/0x30 [ 30.423021] [] do_double_fault+0x10b/0x210 [ 30.428873] [] double_fault+0x2d/0x40 [ 30.434291] [] ? dump_page_badflags+0x180/0x250 [ 30.440573] [] ? dump_page_badflags+0x1a/0x250 [ 30.446768] <> [ 30.450122] Dumping ftrace buffer: [ 30.453918] (ftrace buffer empty) [ 30.457595] Kernel Offset: disabled [ 30.461196] Rebooting in 86400 seconds..