[ 16.085528] 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: [ 19.735354] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available) [ 20.061089] random: sshd: uninitialized urandom read (32 bytes read, 42 bits of entropy available) [ 21.233918] random: sshd: uninitialized urandom read (32 bytes read, 91 bits of entropy available) [ 21.448526] random: sshd: uninitialized urandom read (32 bytes read, 97 bits of entropy available) Warning: Permanently added '10.128.15.224' (ECDSA) to the list of known hosts. [ 26.877846] random: sshd: uninitialized urandom read (32 bytes read, 111 bits of entropy available) executing program [ 26.972756] ================================================================== [ 26.980168] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 26.986820] Read of size 8 at addr ffff8800b4dbf738 by task syzkaller099308/3646 [ 26.994321] [ 26.995920] CPU: 0 PID: 3646 Comm: syzkaller099308 Not tainted 4.4.112-g5f6325b #28 [ 27.003679] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.013637] 0000000000000000 835294ff984593fb ffff8801ce8378d0 ffffffff81d0579d [ 27.021630] ffffea0002d36f80 ffff8800b4dbf738 0000000000000000 ffff8800b4dbf738 [ 27.029603] 0000000000000000 ffff8801ce837908 ffffffff814fd9f3 ffff8800b4dbf738 [ 27.037597] Call Trace: [ 27.040160] [] dump_stack+0xc1/0x124 [ 27.045494] [] print_address_description+0x73/0x260 [ 27.052128] [] kasan_report+0x285/0x370 [ 27.057721] [] ? __lock_acquire+0x387e/0x4b50 [ 27.063835] [] __asan_report_load8_noabort+0x14/0x20 [ 27.070572] [] __lock_acquire+0x387e/0x4b50 [ 27.076513] [] ? __lock_acquire+0xb5f/0x4b50 [ 27.082540] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.089523] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.096503] [] ? mark_held_locks+0xaf/0x100 [ 27.102442] [] lock_acquire+0x15e/0x460 [ 27.108036] [] ? remove_wait_queue+0x14/0x40 [ 27.114064] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 27.120351] [] ? remove_wait_queue+0x14/0x40 [ 27.126377] [] remove_wait_queue+0x14/0x40 [ 27.132234] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 27.139234] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 27.146481] [] ? ep_free+0x1c0/0x1c0 [ 27.151813] [] ep_free+0x93/0x1c0 [ 27.156890] [] ? ep_free+0x1c0/0x1c0 [ 27.162222] [] ep_eventpoll_release+0x44/0x60 [ 27.168337] [] __fput+0x233/0x6d0 [ 27.173423] [] ____fput+0x15/0x20 [ 27.178495] [] task_work_run+0x104/0x180 [ 27.184176] [] do_exit+0x871/0x2a20 [ 27.189431] [] ? release_task+0x1240/0x1240 [ 27.195372] [] ? SyS_epoll_create+0x190/0x190 [ 27.201494] [] do_group_exit+0x108/0x320 [ 27.207173] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 27.213636] [] SyS_exit_group+0x1d/0x20 [ 27.219231] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.225783] [ 27.227389] Allocated by task 3646: [ 27.230982] [] save_stack_trace+0x26/0x50 [ 27.236865] [] save_stack+0x43/0xd0 [ 27.242243] [] kasan_kmalloc+0xad/0xe0 [ 27.247881] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 27.254468] [] binder_get_thread+0x181/0x7a0 [ 27.260622] [] binder_poll+0x4a/0x210 [ 27.266177] [] SyS_epoll_ctl+0x10b1/0x2050 [ 27.272150] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.278818] [ 27.280418] Freed by task 3646: [ 27.283665] [] save_stack_trace+0x26/0x50 [ 27.289550] [] save_stack+0x43/0xd0 [ 27.294923] [] kasan_slab_free+0x72/0xc0 [ 27.300717] [] kfree+0xfc/0x300 [ 27.305734] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 27.312488] [] binder_thread_release+0x27d/0x540 [ 27.318989] [] binder_ioctl+0xb94/0x12e0 [ 27.324789] [] do_vfs_ioctl+0x7aa/0xee0 [ 27.330505] [] SyS_ioctl+0x8f/0xc0 [ 27.335775] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.342438] [ 27.344037] The buggy address belongs to the object at ffff8800b4dbf680 [ 27.344037] which belongs to the cache kmalloc-512 of size 512 [ 27.356675] The buggy address is located 184 bytes inside of [ 27.356675] 512-byte region [ffff8800b4dbf680, ffff8800b4dbf880) [ 27.368539] The buggy address belongs to the page: [ 28.763585] PANIC: double fault, error_code: 0x0 [ 28.768382] CPU: 0 PID: 3646 Comm: syzkaller099308 Not tainted 4.4.112-g5f6325b #28 [ 28.776146] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.785479] task: ffff8800b2fa97c0 task.stack: ffff8801ce830000 [ 28.791506] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 28.800359] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 28.805776] RAX: ffff8800b2fa97c0 RBX: ffffea0002d36f80 RCX: ffffffff8148ff40 [ 28.813025] RDX: 0000000000000000 RSI: ffffffff838a8620 RDI: ffffea0002d36f80 [ 28.820267] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 28.827505] R10: 0000000000000002 R11: fffffbfff0ad7a1e R12: 0000000000000000 [ 28.834743] R13: ffffffff838a8620 R14: 0000000000000000 R15: 0000000000000000 [ 28.842004] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 28.850204] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 28.856055] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 28.863298] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 28.870539] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 28.877950] Stack: [ 28.880068] [ 28.881664] Call Trace: [ 28.884223] [ 28.886269] 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 11 01 ed ff 48 8d 7b 10 48 b8 00 00 00 00 00 fc ff df 48 89 [ 28.913221] Kernel panic - not syncing: Machine halted. [ 28.918565] CPU: 0 PID: 3646 Comm: syzkaller099308 Not tainted 4.4.112-g5f6325b #28 [ 28.926336] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.935660] 0000000000000000 835294ff984593fb ffff8801db20ce38 ffffffff81d0579d [ 28.943629] ffffffff83836a60 ffff8801db20cf10 ffffffff83808040 ffff880100000000 [ 28.951601] 0000000000000000 ffff8801db20cf00 ffffffff81419e6a 0000000041b58ab3 [ 28.959579] Call Trace: [ 28.962133] <#DF> [] dump_stack+0xc1/0x124 [ 28.968728] [] panic+0x1aa/0x388 [ 28.973716] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 28.980621] [] ? vprintk_emit+0x242/0x850 [ 28.986389] [] ? dump_page_badflags+0x2f/0x250 [ 28.992602] [] ? vprintk_emit+0x242/0x850 [ 28.998372] [] df_debug+0x2d/0x30 [ 29.003455] [] do_double_fault+0x10b/0x210 [ 29.010021] [] double_fault+0x2d/0x40 [ 29.015445] [] ? dump_page_badflags+0x180/0x250 [ 29.021735] [] ? dump_page_badflags+0x1a/0x250 [ 29.027934] <> [ 29.031322] Dumping ftrace buffer: [ 29.035127] (ftrace buffer empty) [ 29.038806] Kernel Offset: disabled [ 29.042400] Rebooting in 86400 seconds..