[ 16.116214] random: sshd: uninitialized urandom read (32 bytes read, 33 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: [ 20.772520] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available) [ 21.134258] random: sshd: uninitialized urandom read (32 bytes read, 40 bits of entropy available) [ 21.866667] random: sshd: uninitialized urandom read (32 bytes read, 86 bits of entropy available) [ 22.050487] random: sshd: uninitialized urandom read (32 bytes read, 91 bits of entropy available) Warning: Permanently added '10.128.15.232' (ECDSA) to the list of known hosts. [ 27.427327] random: sshd: uninitialized urandom read (32 bytes read, 100 bits of entropy available) executing program [ 27.526818] ================================================================== [ 27.534224] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 27.540861] Read of size 8 at addr ffff8800b441c838 by task syzkaller135928/3314 [ 27.548373] [ 27.549977] CPU: 0 PID: 3314 Comm: syzkaller135928 Not tainted 4.4.110-gd891a62 #19 [ 27.557735] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.567066] 0000000000000000 e56fe5e0a5e7018e ffff8801d0f778b0 ffffffff81d04e3d [ 27.575019] ffffea0002d10700 ffff8800b441c838 0000000000000000 ffff8800b441c838 [ 27.582985] 0000000000000000 ffff8801d0f778e8 ffffffff814fd1f3 ffff8800b441c838 [ 27.590944] Call Trace: [ 27.593506] [] dump_stack+0xc1/0x124 [ 27.598837] [] print_address_description+0x73/0x260 [ 27.605477] [] kasan_report+0x285/0x370 [ 27.611069] [] ? __lock_acquire+0x387e/0x4b50 [ 27.617177] [] __asan_report_load8_noabort+0x14/0x20 [ 27.623894] [] __lock_acquire+0x387e/0x4b50 [ 27.629830] [] ? is_module_text_address+0x2a/0x50 [ 27.636298] [] ? __lock_acquire+0xb5f/0x4b50 [ 27.642324] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.649301] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.656281] [] ? __lock_is_held+0xa1/0xf0 [ 27.662043] [] lock_acquire+0x15e/0x460 [ 27.667633] [] ? remove_wait_queue+0x14/0x40 [ 27.673656] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 27.679945] [] ? remove_wait_queue+0x14/0x40 [ 27.685980] [] remove_wait_queue+0x14/0x40 [ 27.691831] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 27.698810] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 27.706055] [] ep_remove+0x41/0x290 [ 27.711299] [] eventpoll_release_file+0xc5/0x140 [ 27.717687] [] __fput+0x521/0x6d0 [ 27.722760] [] ____fput+0x15/0x20 [ 27.727829] [] task_work_run+0x104/0x180 [ 27.733506] [] do_exit+0x871/0x2a20 [ 27.738747] [] ? release_task+0x1240/0x1240 [ 27.744683] [] ? SyS_epoll_create+0x190/0x190 [ 27.750793] [] do_group_exit+0x108/0x320 [ 27.756471] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 27.762928] [] SyS_exit_group+0x1d/0x20 [ 27.768519] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.775078] [ 27.776674] Allocated by task 3314: [ 27.780265] [] save_stack_trace+0x26/0x50 [ 27.786151] [] save_stack+0x43/0xd0 [ 27.791512] [] kasan_kmalloc+0xad/0xe0 [ 27.797136] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 27.803707] [] binder_get_thread+0x181/0x7a0 [ 27.810105] [] binder_poll+0x4a/0x210 [ 27.815634] [] SyS_epoll_ctl+0x10b1/0x2050 [ 27.821696] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.828353] [ 27.829953] Freed by task 3314: [ 27.833194] [] save_stack_trace+0x26/0x50 [ 27.839192] [] save_stack+0x43/0xd0 [ 27.844551] [] kasan_slab_free+0x72/0xc0 [ 27.850341] [] kfree+0xfc/0x300 [ 27.855350] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 27.862097] [] binder_thread_release+0x27d/0x540 [ 27.868581] [] binder_ioctl+0xb94/0x12e0 [ 27.874372] [] do_vfs_ioctl+0x7aa/0xee0 [ 27.880075] [] SyS_ioctl+0x8f/0xc0 [ 27.885353] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.892024] [ 27.893621] The buggy address belongs to the object at ffff8800b441c780 [ 27.893621] which belongs to the cache kmalloc-512 of size 512 [ 27.906250] The buggy address is located 184 bytes inside of [ 27.906250] 512-byte region [ffff8800b441c780, ffff8800b441c980) [ 27.918091] The buggy address belongs to the page: [ 29.423094] PANIC: double fault, error_code: 0x0 [ 29.427875] CPU: 0 PID: 3314 Comm: syzkaller135928 Not tainted 4.4.110-gd891a62 #19 [ 29.435633] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.444951] task: ffff8801d23797c0 task.stack: ffff8801d0f70000 [ 29.450970] RIP: 0010:[] [] dump_page_badflags+0x8/0x250 [ 29.459717] RSP: 0018:ffff880100000000 EFLAGS: 00010046 [ 29.465130] RAX: ffff8801d23797c0 RBX: ffffea0002d10700 RCX: ffffffff8148f740 [ 29.472364] RDX: 0000000000000000 RSI: ffffffff838a8320 RDI: ffffea0002d10700 [ 29.479599] RBP: ffff880100000010 R08: 0000000000000001 R09: 0000000000000000 [ 29.486843] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 29.494076] R13: ffffffff838a8320 R14: 0000000000000000 R15: 0000000000000000 [ 29.501311] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 29.509503] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 29.515349] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 29.522587] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.529822] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.537069] Stack: [ 29.539182] [ 29.540780] Call Trace: [ 29.543325] [ 29.545350] Code: 00 e9 83 fd ff ff e8 a8 e2 06 00 e9 50 fd ff ff e8 9e 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 e8 61 06 [ 29.571990] Kernel panic - not syncing: Machine halted. [ 29.577321] CPU: 0 PID: 3314 Comm: syzkaller135928 Not tainted 4.4.110-gd891a62 #19 [ 29.585078] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.594396] 0000000000000000 e56fe5e0a5e7018e ffff8801db20ce38 ffffffff81d04e3d [ 29.602353] ffffffff838367c0 ffff8801db20cf10 ffffffff83808040 ffff880100000000 [ 29.610301] 0000000000000000 ffff8801db20cf00 ffffffff814197fa 0000000041b58ab3 [ 29.618257] Call Trace: [ 29.620803] <#DF> [] dump_stack+0xc1/0x124 [ 29.626861] [] panic+0x1aa/0x388 [ 29.631852] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 29.638744] [] ? vprintk_emit+0x242/0x850 [ 29.644517] [] ? dump_page_badflags+0x1d/0x250 [ 29.650711] [] ? vprintk_emit+0x242/0x850 [ 29.656473] [] df_debug+0x2d/0x30 [ 29.661557] [] do_double_fault+0x10b/0x210 [ 29.667408] [] double_fault+0x2d/0x40 [ 29.672822] [] ? dump_page_badflags+0x180/0x250 [ 29.679109] [] ? dump_page_badflags+0x8/0x250 [ 29.685217] <> [ 29.688634] Dumping ftrace buffer: [ 29.692428] (ftrace buffer empty) [ 29.696105] Kernel Offset: disabled [ 29.699697] Rebooting in 86400 seconds..