[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.614806] random: sshd: uninitialized urandom read (32 bytes read, 33 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 22.245466] random: sshd: uninitialized urandom read (32 bytes read, 40 bits of entropy available) [ 22.668545] random: sshd: uninitialized urandom read (32 bytes read, 40 bits of entropy available) [ 23.458812] random: sshd: uninitialized urandom read (32 bytes read, 92 bits of entropy available) [ 23.659986] random: sshd: uninitialized urandom read (32 bytes read, 97 bits of entropy available) Warning: Permanently added '10.128.0.29' (ECDSA) to the list of known hosts. [ 29.045277] random: sshd: uninitialized urandom read (32 bytes read, 106 bits of entropy available) executing program [ 29.143148] ================================================================== [ 29.150548] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 29.157182] Read of size 8 at addr ffff8800b4bb0338 by task syzkaller049393/3325 [ 29.164680] [ 29.166275] CPU: 1 PID: 3325 Comm: syzkaller049393 Not tainted 4.4.111-g3301b55 #24 [ 29.174034] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.183360] 0000000000000000 57e01453d3bffe07 ffff8801cfc2f8d0 ffffffff81d0509d [ 29.191328] ffffea0002d2ec00 ffff8800b4bb0338 0000000000000000 ffff8800b4bb0338 [ 29.199284] 0000000000000000 ffff8801cfc2f908 ffffffff814fd433 ffff8800b4bb0338 [ 29.207257] Call Trace: [ 29.209820] [] dump_stack+0xc1/0x124 [ 29.215151] [] print_address_description+0x73/0x260 [ 29.221789] [] kasan_report+0x285/0x370 [ 29.227382] [] ? __lock_acquire+0x387e/0x4b50 [ 29.233495] [] __asan_report_load8_noabort+0x14/0x20 [ 29.240215] [] __lock_acquire+0x387e/0x4b50 [ 29.246150] [] ? __lock_acquire+0xb5f/0x4b50 [ 29.252173] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 29.259153] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 29.266142] [] ? mark_held_locks+0xaf/0x100 [ 29.272079] [] lock_acquire+0x15e/0x460 [ 29.277684] [] ? remove_wait_queue+0x14/0x40 [ 29.283715] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 29.290007] [] ? remove_wait_queue+0x14/0x40 [ 29.296037] [] remove_wait_queue+0x14/0x40 [ 29.301892] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 29.308875] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 29.316113] [] ? ep_free+0x1c0/0x1c0 [ 29.321455] [] ep_free+0x93/0x1c0 [ 29.326527] [] ? ep_free+0x1c0/0x1c0 [ 29.331857] [] ep_eventpoll_release+0x44/0x60 [ 29.337967] [] __fput+0x233/0x6d0 [ 29.343036] [] ____fput+0x15/0x20 [ 29.348111] [] task_work_run+0x104/0x180 [ 29.353797] [] do_exit+0x871/0x2a20 [ 29.359045] [] ? release_task+0x1240/0x1240 [ 29.364984] [] ? SyS_epoll_create+0x190/0x190 [ 29.371108] [] ? fd_install+0x4d/0x60 [ 29.376530] [] do_group_exit+0x108/0x320 [ 29.382216] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 29.388681] [] SyS_exit_group+0x1d/0x20 [ 29.394272] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 29.400815] [ 29.402414] Allocated by task 3325: [ 29.406002] [] save_stack_trace+0x26/0x50 [ 29.411882] [] save_stack+0x43/0xd0 [ 29.417245] [] kasan_kmalloc+0xad/0xe0 [ 29.422857] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 29.429427] [] binder_get_thread+0x181/0x7a0 [ 29.435565] [] binder_poll+0x4a/0x210 [ 29.441103] [] SyS_epoll_ctl+0x10b1/0x2050 [ 29.447080] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 29.453740] [ 29.455337] Freed by task 3325: [ 29.458578] [] save_stack_trace+0x26/0x50 [ 29.464457] [] save_stack+0x43/0xd0 [ 29.469827] [] kasan_slab_free+0x72/0xc0 [ 29.475619] [] kfree+0xfc/0x300 [ 29.480624] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 29.487372] [] binder_thread_release+0x27d/0x540 [ 29.493862] [] binder_ioctl+0xb94/0x12e0 [ 29.499655] [] do_vfs_ioctl+0x7aa/0xee0 [ 29.505369] [] SyS_ioctl+0x8f/0xc0 [ 29.510641] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 29.517310] [ 29.518911] The buggy address belongs to the object at ffff8800b4bb0280 [ 29.518911] which belongs to the cache kmalloc-512 of size 512 [ 29.531540] The buggy address is located 184 bytes inside of [ 29.531540] 512-byte region [ffff8800b4bb0280, ffff8800b4bb0480) [ 29.543380] The buggy address belongs to the page: [ 30.995912] PANIC: double fault, error_code: 0x0 [ 31.000700] CPU: 1 PID: 3325 Comm: syzkaller049393 Not tainted 4.4.111-g3301b55 #24 [ 31.008464] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.017785] task: ffff8800b49397c0 task.stack: ffff8801cfc28000 [ 31.023806] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 31.032645] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 31.038068] RAX: ffff8800b49397c0 RBX: ffffea0002d2ec00 RCX: ffffffff8148f980 [ 31.045306] RDX: 0000000000000000 RSI: ffffffff838a83a0 RDI: ffffea0002d2ec00 [ 31.052543] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 31.059791] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 31.067029] R13: ffffffff838a83a0 R14: 0000000000000000 R15: 0000000000000000 [ 31.074269] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 31.082462] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 31.088310] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 31.095550] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 31.102787] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 31.110023] Stack: [ 31.112137] [ 31.113730] Call Trace: [ 31.116276] [ 31.118303] 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 [ 31.144933] Kernel panic - not syncing: Machine halted. [ 31.150264] CPU: 1 PID: 3325 Comm: syzkaller049393 Not tainted 4.4.111-g3301b55 #24 [ 31.158022] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.167343] 0000000000000000 57e01453d3bffe07 ffff8801db30ce38 ffffffff81d0509d [ 31.175292] ffffffff838367c0 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 31.183244] 0000000000000000 ffff8801db30cf00 ffffffff81419a3a 0000000041b58ab3 [ 31.191191] Call Trace: [ 31.193740] <#DF> [] dump_stack+0xc1/0x124 [ 31.199806] [] panic+0x1aa/0x388 [ 31.204788] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 31.211681] [] ? vprintk_emit+0x242/0x850 [ 31.217459] [] ? dump_page_badflags+0x2f/0x250 [ 31.223670] [] ? vprintk_emit+0x242/0x850 [ 31.229448] [] df_debug+0x2d/0x30 [ 31.234521] [] do_double_fault+0x10b/0x210 [ 31.240377] [] double_fault+0x2d/0x40 [ 31.245796] [] ? dump_page_badflags+0x180/0x250 [ 31.252080] [] ? dump_page_badflags+0x1a/0x250 [ 31.258275] <> [ 31.261657] Dumping ftrace buffer: [ 31.265448] (ftrace buffer empty) [ 31.269124] Kernel Offset: disabled [ 31.272717] Rebooting in 86400 seconds..