[ 15.278239] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 20.563795] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 20.875383] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 21.634700] random: sshd: uninitialized urandom read (32 bytes read, 94 bits of entropy available) [ 21.815540] random: sshd: uninitialized urandom read (32 bytes read, 99 bits of entropy available) Warning: Permanently added '10.128.15.219' (ECDSA) to the list of known hosts. [ 27.186924] random: sshd: uninitialized urandom read (32 bytes read, 107 bits of entropy available) executing program [ 27.285476] ================================================================== [ 27.292864] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 27.299501] Read of size 8 at addr ffff8800b41365b8 by task syzkaller305037/3311 [ 27.306995] [ 27.308589] CPU: 1 PID: 3311 Comm: syzkaller305037 Not tainted 4.4.111-g7902639 #25 [ 27.317648] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.328705] 0000000000000000 0f817f30691fdd74 ffff8801d10f78d0 ffffffff81d0509d [ 27.336663] ffffea0002d04d80 ffff8800b41365b8 0000000000000000 ffff8800b41365b8 [ 27.344600] 0000000000000000 ffff8801d10f7908 ffffffff814fd433 ffff8800b41365b8 [ 27.352553] Call Trace: [ 27.355105] [] dump_stack+0xc1/0x124 [ 27.360444] [] print_address_description+0x73/0x260 [ 27.367073] [] kasan_report+0x285/0x370 [ 27.372660] [] ? __lock_acquire+0x387e/0x4b50 [ 27.378767] [] __asan_report_load8_noabort+0x14/0x20 [ 27.385483] [] __lock_acquire+0x387e/0x4b50 [ 27.391415] [] ? __lock_acquire+0xb5f/0x4b50 [ 27.397440] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.404418] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.411395] [] ? mark_held_locks+0xaf/0x100 [ 27.417329] [] lock_acquire+0x15e/0x460 [ 27.422916] [] ? remove_wait_queue+0x14/0x40 [ 27.428940] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 27.435221] [] ? remove_wait_queue+0x14/0x40 [ 27.441242] [] remove_wait_queue+0x14/0x40 [ 27.447092] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 27.454068] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 27.461304] [] ? ep_free+0x1c0/0x1c0 [ 27.466630] [] ep_free+0x93/0x1c0 [ 27.471698] [] ? ep_free+0x1c0/0x1c0 [ 27.477031] [] ep_eventpoll_release+0x44/0x60 [ 27.483141] [] __fput+0x233/0x6d0 [ 27.488207] [] ____fput+0x15/0x20 [ 27.493274] [] task_work_run+0x104/0x180 [ 27.498947] [] do_exit+0x871/0x2a20 [ 27.504187] [] ? release_task+0x1240/0x1240 [ 27.510126] [] ? SyS_epoll_create+0x190/0x190 [ 27.516233] [] do_group_exit+0x108/0x320 [ 27.521906] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 27.528360] [] SyS_exit_group+0x1d/0x20 [ 27.533953] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.540840] [ 27.542781] Allocated by task 3311: [ 27.547846] [] save_stack_trace+0x26/0x50 [ 27.555034] [] save_stack+0x43/0xd0 [ 27.560388] [] kasan_kmalloc+0xad/0xe0 [ 27.565998] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 27.572569] [] binder_get_thread+0x181/0x7a0 [ 27.578706] [] binder_poll+0x4a/0x210 [ 27.584238] [] SyS_epoll_ctl+0x10b1/0x2050 [ 27.590200] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.596854] [ 27.598446] Freed by task 3311: [ 27.601684] [] save_stack_trace+0x26/0x50 [ 27.607558] [] save_stack+0x43/0xd0 [ 27.613258] [] kasan_slab_free+0x72/0xc0 [ 27.619042] [] kfree+0xfc/0x300 [ 27.624047] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 27.630795] [] binder_thread_release+0x27d/0x540 [ 27.637287] [] binder_ioctl+0xb94/0x12e0 [ 27.643073] [] do_vfs_ioctl+0x7aa/0xee0 [ 27.648772] [] SyS_ioctl+0x8f/0xc0 [ 27.654036] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.660697] [ 27.662292] The buggy address belongs to the object at ffff8800b4136500 [ 27.662292] which belongs to the cache kmalloc-512 of size 512 [ 27.674910] The buggy address is located 184 bytes inside of [ 27.674910] 512-byte region [ffff8800b4136500, ffff8800b4136700) [ 27.686744] The buggy address belongs to the page: [ 29.066926] PANIC: double fault, error_code: 0x0 [ 29.071690] CPU: 1 PID: 3311 Comm: syzkaller305037 Not tainted 4.4.111-g7902639 #25 [ 29.080141] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.089460] task: ffff8800b5744740 task.stack: ffff8801d10f0000 [ 29.095480] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 29.104747] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 29.110940] RAX: ffff8800b5744740 RBX: ffffea0002d04d80 RCX: ffffffff8148f980 [ 29.118435] RDX: 0000000000000000 RSI: ffffffff838a8360 RDI: ffffea0002d04d80 [ 29.125840] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 29.133077] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 29.140312] R13: ffffffff838a8360 R14: 0000000000000000 R15: 0000000000000000 [ 29.147546] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 29.155735] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 29.161581] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 29.168814] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.176048] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.183282] Stack: [ 29.185400] [ 29.186990] Call Trace: [ 29.189536] [ 29.191561] 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 [ 29.220067] Kernel panic - not syncing: Machine halted. [ 29.225922] CPU: 1 PID: 3311 Comm: syzkaller305037 Not tainted 4.4.111-g7902639 #25 [ 29.233676] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.242999] 0000000000000000 0f817f30691fdd74 ffff8801db30ce38 ffffffff81d0509d [ 29.250947] ffffffff838367c0 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 29.258885] 0000000000000000 ffff8801db30cf00 ffffffff81419a3a 0000000041b58ab3 [ 29.266825] Call Trace: [ 29.269369] <#DF> [] dump_stack+0xc1/0x124 [ 29.276489] [] panic+0x1aa/0x388 [ 29.281473] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 29.288362] [] ? vprintk_emit+0x242/0x850 [ 29.294128] [] ? dump_page_badflags+0x2f/0x250 [ 29.300323] [] ? vprintk_emit+0x242/0x850 [ 29.306084] [] df_debug+0x2d/0x30 [ 29.311151] [] do_double_fault+0x10b/0x210 [ 29.317522] [] double_fault+0x2d/0x40 [ 29.322936] [] ? dump_page_badflags+0x180/0x250 [ 29.329220] [] ? dump_page_badflags+0x1a/0x250 [ 29.335412] <> [ 29.338755] Dumping ftrace buffer: [ 29.342544] (ftrace buffer empty) [ 29.346217] Kernel Offset: disabled [ 29.349808] Rebooting in 86400 seconds..