[ 16.070460] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.630928] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 21.868705] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 22.663468] random: sshd: uninitialized urandom read (32 bytes read, 82 bits of entropy available) [ 23.304649] random: sshd: uninitialized urandom read (32 bytes read, 88 bits of entropy available) Warning: Permanently added '10.128.0.62' (ECDSA) to the list of known hosts. [ 28.672864] random: sshd: uninitialized urandom read (32 bytes read, 95 bits of entropy available) executing program [ 28.769679] ================================================================== [ 28.777073] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 28.783705] Read of size 8 at addr ffff8801d04c3c38 by task syzkaller456678/3324 [ 28.791212] [ 28.792811] CPU: 0 PID: 3324 Comm: syzkaller456678 Not tainted 4.4.111-gc2f631b #27 [ 28.800582] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.809910] 0000000000000000 4200924e1aee0249 ffff8801cfc1f8d0 ffffffff81d0513d [ 28.817873] ffffea0007413080 ffff8801d04c3c38 0000000000000000 ffff8801d04c3c38 [ 28.825837] 0000000000000000 ffff8801cfc1f908 ffffffff814fd433 ffff8801d04c3c38 [ 28.833816] Call Trace: [ 28.836376] [] dump_stack+0xc1/0x124 [ 28.841721] [] print_address_description+0x73/0x260 [ 28.848353] [] kasan_report+0x285/0x370 [ 28.853958] [] ? __lock_acquire+0x387e/0x4b50 [ 28.860082] [] __asan_report_load8_noabort+0x14/0x20 [ 28.866815] [] __lock_acquire+0x387e/0x4b50 [ 28.872757] [] ? __lock_acquire+0xb5f/0x4b50 [ 28.878785] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.885767] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.892747] [] ? mark_held_locks+0xaf/0x100 [ 28.898688] [] lock_acquire+0x15e/0x460 [ 28.904281] [] ? remove_wait_queue+0x14/0x40 [ 28.910321] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 28.916609] [] ? remove_wait_queue+0x14/0x40 [ 28.922636] [] remove_wait_queue+0x14/0x40 [ 28.928494] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 28.935493] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 28.942737] [] ? ep_free+0x1c0/0x1c0 [ 28.948074] [] ep_free+0x93/0x1c0 [ 28.953144] [] ? ep_free+0x1c0/0x1c0 [ 28.958477] [] ep_eventpoll_release+0x44/0x60 [ 28.964598] [] __fput+0x233/0x6d0 [ 28.969680] [] ____fput+0x15/0x20 [ 28.974755] [] task_work_run+0x104/0x180 [ 28.980440] [] do_exit+0x871/0x2a20 [ 28.985688] [] ? release_task+0x1240/0x1240 [ 28.991743] [] ? SyS_epoll_create+0x190/0x190 [ 28.997867] [] do_group_exit+0x108/0x320 [ 29.003556] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 29.010018] [] SyS_exit_group+0x1d/0x20 [ 29.015614] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 29.022161] [ 29.023758] Allocated by task 3324: [ 29.027351] [] save_stack_trace+0x26/0x50 [ 29.033236] [] save_stack+0x43/0xd0 [ 29.038600] [] kasan_kmalloc+0xad/0xe0 [ 29.044222] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 29.050811] [] binder_get_thread+0x181/0x7a0 [ 29.056956] [] binder_poll+0x4a/0x210 [ 29.062488] [] SyS_epoll_ctl+0x10b1/0x2050 [ 29.068464] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 29.075145] [ 29.076742] Freed by task 3324: [ 29.079987] [] save_stack_trace+0x26/0x50 [ 29.085872] [] save_stack+0x43/0xd0 [ 29.091236] [] kasan_slab_free+0x72/0xc0 [ 29.097031] [] kfree+0xfc/0x300 [ 29.102044] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 29.108794] [] binder_thread_release+0x27d/0x540 [ 29.115286] [] binder_ioctl+0xb94/0x12e0 [ 29.121084] [] do_vfs_ioctl+0x7aa/0xee0 [ 29.126792] [] SyS_ioctl+0x8f/0xc0 [ 29.132080] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 29.138744] [ 29.140345] The buggy address belongs to the object at ffff8801d04c3b80 [ 29.140345] which belongs to the cache kmalloc-512 of size 512 [ 29.152971] The buggy address is located 184 bytes inside of [ 29.152971] 512-byte region [ffff8801d04c3b80, ffff8801d04c3d80) [ 29.164826] The buggy address belongs to the page: [ 30.608090] PANIC: double fault, error_code: 0x0 [ 30.612876] CPU: 0 PID: 3324 Comm: syzkaller456678 Not tainted 4.4.111-gc2f631b #27 [ 30.620641] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.629968] task: ffff8800b44e17c0 task.stack: ffff8801cfc18000 [ 30.635992] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 30.644860] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 30.650284] RAX: ffff8800b44e17c0 RBX: ffffea0007413080 RCX: ffffffff8148f980 [ 30.657534] RDX: 0000000000000000 RSI: ffffffff838a8360 RDI: ffffea0007413080 [ 30.664775] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 30.672015] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 30.679256] R13: ffffffff838a8360 R14: 0000000000000000 R15: 0000000000000000 [ 30.686500] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 30.694694] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 30.700556] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 30.707807] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 30.715045] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 30.722283] Stack: [ 30.724398] [ 30.725996] Call Trace: [ 30.728558] [ 30.730587] 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 [ 30.757486] Kernel panic - not syncing: Machine halted. [ 30.762822] CPU: 0 PID: 3324 Comm: syzkaller456678 Not tainted 4.4.111-gc2f631b #27 [ 30.770593] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.779918] 0000000000000000 4200924e1aee0249 ffff8801db20ce38 ffffffff81d0513d [ 30.787885] ffffffff838367c0 ffff8801db20cf10 ffffffff83808040 ffff880100000000 [ 30.795854] 0000000000000000 ffff8801db20cf00 ffffffff81419a3a 0000000041b58ab3 [ 30.803844] Call Trace: [ 30.806401] <#DF> [] dump_stack+0xc1/0x124 [ 30.812478] [] panic+0x1aa/0x388 [ 30.817475] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 30.824373] [] ? vprintk_emit+0x242/0x850 [ 30.830143] [] ? dump_page_badflags+0x2f/0x250 [ 30.836346] [] ? vprintk_emit+0x242/0x850 [ 30.842118] [] df_debug+0x2d/0x30 [ 30.847192] [] do_double_fault+0x10b/0x210 [ 30.853050] [] double_fault+0x2d/0x40 [ 30.858471] [] ? dump_page_badflags+0x180/0x250 [ 30.864759] [] ? dump_page_badflags+0x1a/0x250 [ 30.870956] <> [ 30.874318] Dumping ftrace buffer: [ 30.878123] (ftrace buffer empty) [ 30.881805] Kernel Offset: disabled [ 30.885400] Rebooting in 86400 seconds..