[ 16.519552] 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: [ 20.575134] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 20.984275] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 21.930455] random: sshd: uninitialized urandom read (32 bytes read, 109 bits of entropy available) [ 22.106922] random: sshd: uninitialized urandom read (32 bytes read, 115 bits of entropy available) Warning: Permanently added '10.128.0.21' (ECDSA) to the list of known hosts. [ 27.496939] random: sshd: uninitialized urandom read (32 bytes read, 122 bits of entropy available) executing program [ 27.596304] ================================================================== [ 27.603717] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 27.610354] Read of size 8 at addr ffff8801d2c52d38 by task syzkaller031825/3314 [ 27.617862] [ 27.619461] CPU: 1 PID: 3314 Comm: syzkaller031825 Not tainted 4.4.113-g202e079 #1 [ 27.627145] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.636479] 0000000000000000 12accc22d270e468 ffff8801d0b1f8f0 ffffffff81d0278d [ 27.644462] ffffea00074b1480 ffff8801d2c52d38 0000000000000000 ffff8801d2c52d38 [ 27.652433] 0000000000000000 ffff8801d0b1f928 ffffffff814fd053 ffff8801d2c52d38 [ 27.660399] Call Trace: [ 27.662960] [] dump_stack+0xc1/0x124 [ 27.668290] [] print_address_description+0x73/0x260 [ 27.674923] [] kasan_report+0x285/0x370 [ 27.680518] [] ? __lock_acquire+0x387e/0x4b50 [ 27.686642] [] __asan_report_load8_noabort+0x14/0x20 [ 27.693373] [] __lock_acquire+0x387e/0x4b50 [ 27.699312] [] ? __lock_acquire+0xb5f/0x4b50 [ 27.705338] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.712321] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.719303] [] ? mark_held_locks+0xaf/0x100 [ 27.725241] [] lock_acquire+0x15e/0x460 [ 27.730839] [] ? remove_wait_queue+0x14/0x40 [ 27.736878] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 27.743165] [] ? remove_wait_queue+0x14/0x40 [ 27.749191] [] remove_wait_queue+0x14/0x40 [ 27.755048] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 27.762029] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 27.769271] [] ? ep_free+0x1c0/0x1c0 [ 27.774603] [] ep_free+0x93/0x1c0 [ 27.779675] [] ? ep_free+0x1c0/0x1c0 [ 27.785017] [] ep_eventpoll_release+0x44/0x60 [ 27.791133] [] __fput+0x233/0x6d0 [ 27.796204] [] ____fput+0x15/0x20 [ 27.801275] [] task_work_run+0x104/0x180 [ 27.806957] [] do_exit+0x82a/0x2a10 [ 27.812204] [] ? binder_ioctl_write_read.isra.55+0xbc0/0xbc0 [ 27.819623] [] ? release_task+0x1240/0x1240 [ 27.825564] [] ? SyS_epoll_create+0x190/0x190 [ 27.831677] [] do_group_exit+0x108/0x320 [ 27.837358] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 27.843821] [] SyS_exit_group+0x1d/0x20 [ 27.849427] [] entry_SYSCALL_64_fastpath+0x1c/0x98 [ 27.855981] [ 27.857579] Allocated by task 3314: [ 27.861171] [] save_stack_trace+0x26/0x50 [ 27.867068] [] save_stack+0x43/0xd0 [ 27.872432] [] kasan_kmalloc+0xad/0xe0 [ 27.878057] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 27.884633] [] binder_get_thread+0x15d/0x750 [ 27.890789] [] binder_poll+0x4a/0x210 [ 27.896346] [] SyS_epoll_ctl+0x10b1/0x2040 [ 27.902320] [] entry_SYSCALL_64_fastpath+0x1c/0x98 [ 27.908995] [ 27.910592] Freed by task 3314: [ 27.913837] [] save_stack_trace+0x26/0x50 [ 27.919722] [] save_stack+0x43/0xd0 [ 27.925086] [] kasan_slab_free+0x72/0xc0 [ 27.930884] [] kfree+0xfc/0x300 [ 27.935908] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 27.942663] [] binder_thread_release+0x27d/0x540 [ 27.949160] [] binder_ioctl+0xb94/0x12e0 [ 27.954957] [] do_vfs_ioctl+0x7aa/0xee0 [ 27.960679] [] SyS_ioctl+0x8f/0xc0 [ 27.965962] [] entry_SYSCALL_64_fastpath+0x1c/0x98 [ 27.972637] [ 27.974233] The buggy address belongs to the object at ffff8801d2c52c80 [ 27.974233] which belongs to the cache kmalloc-512 of size 512 [ 27.986869] The buggy address is located 184 bytes inside of [ 27.986869] 512-byte region [ffff8801d2c52c80, ffff8801d2c52e80) [ 27.998708] The buggy address belongs to the page: [ 29.568163] PANIC: double fault, error_code: 0x0 [ 29.572951] CPU: 1 PID: 3314 Comm: syzkaller031825 Not tainted 4.4.113-g202e079 #1 [ 29.580628] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.589954] task: ffff8801d2b9c740 task.stack: ffff8801d0b18000 [ 29.595989] RIP: 0010:[] [] dump_page_badflags+0x8/0x250 [ 29.604751] RSP: 0018:ffff880100000000 EFLAGS: 00010046 [ 29.610168] RAX: ffff8801d2b9c740 RBX: ffffea00074b1480 RCX: ffffffff8148f8d0 [ 29.617419] RDX: 0000000000000000 RSI: ffffffff838a8de0 RDI: ffffea00074b1480 [ 29.624669] RBP: ffff880100000010 R08: 0000000000000001 R09: 0000000000000000 [ 29.631910] R10: 0000000000000002 R11: fffffbfff0ad7e26 R12: 0000000000000000 [ 29.639160] R13: ffffffff838a8de0 R14: 0000000000000000 R15: 0000000000000000 [ 29.646403] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 29.654599] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 29.660453] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 29.667695] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.674934] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.682181] Stack: [ 29.684296] [ 29.685893] Call Trace: [ 29.688449] [ 29.690480] Code: 00 e9 83 fd ff ff e8 78 df 06 00 e9 50 fd ff ff e8 6e df 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 b1 04 [ 29.717346] Kernel panic - not syncing: Machine halted. [ 29.722679] CPU: 1 PID: 3314 Comm: syzkaller031825 Not tainted 4.4.113-g202e079 #1 [ 29.730366] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.739703] 0000000000000000 12accc22d270e468 ffff8801db30ce38 ffffffff81d0278d [ 29.747695] ffffffff83837200 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 29.755671] 0000000000000000 ffff8801db30cf00 ffffffff81419b6a 0000000041b58ab3 [ 29.763638] Call Trace: [ 29.766188] <#DF> [] dump_stack+0xc1/0x124 [ 29.772254] [] panic+0x1aa/0x388 [ 29.777241] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 29.784135] [] ? vprintk_emit+0x242/0x850 [ 29.789901] [] ? dump_page_badflags+0x1d/0x250 [ 29.796102] [] ? vprintk_emit+0x242/0x850 [ 29.801872] [] df_debug+0x2d/0x30 [ 29.806946] [] do_double_fault+0x10b/0x210 [ 29.812810] [] double_fault+0x2d/0x40 [ 29.818228] [] ? dump_page_badflags+0x180/0x250 [ 29.824514] [] ? dump_page_badflags+0x8/0x250 [ 29.830649] <> [ 29.834038] Dumping ftrace buffer: [ 29.837841] (ftrace buffer empty) [ 29.841523] Kernel Offset: disabled [ 29.845126] Rebooting in 86400 seconds..