[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 15.848241] random: sshd: uninitialized urandom read (32 bytes read, 31 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.893872] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 22.298319] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 23.189315] random: sshd: uninitialized urandom read (32 bytes read, 106 bits of entropy available) [ 23.363601] random: sshd: uninitialized urandom read (32 bytes read, 111 bits of entropy available) Warning: Permanently added '10.128.15.248' (ECDSA) to the list of known hosts. [ 28.742063] random: sshd: uninitialized urandom read (32 bytes read, 121 bits of entropy available) executing program [ 28.844436] ================================================================== [ 28.851846] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 28.858492] Read of size 8 at addr ffff8801cfc18838 by task syzkaller004132/3316 [ 28.865992] [ 28.867596] CPU: 1 PID: 3316 Comm: syzkaller004132 Not tainted 4.4.112-gd96d95d #31 [ 28.875361] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.884697] 0000000000000000 e04b3d39d611006d ffff8801d04bf8d0 ffffffff81d054ed [ 28.892681] ffffea00073f0600 ffff8801cfc18838 0000000000000000 ffff8801cfc18838 [ 28.900661] 0000000000000000 ffff8801d04bf908 ffffffff814fd953 ffff8801cfc18838 [ 28.908641] Call Trace: [ 28.911212] [] dump_stack+0xc1/0x124 [ 28.916549] [] print_address_description+0x73/0x260 [ 28.923194] [] kasan_report+0x285/0x370 [ 28.928790] [] ? __lock_acquire+0x387e/0x4b50 [ 28.935008] [] __asan_report_load8_noabort+0x14/0x20 [ 28.941748] [] __lock_acquire+0x387e/0x4b50 [ 28.947691] [] ? __lock_acquire+0xb5f/0x4b50 [ 28.953723] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.960725] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.967710] [] ? mark_held_locks+0xaf/0x100 [ 28.973660] [] lock_acquire+0x15e/0x460 [ 28.979265] [] ? remove_wait_queue+0x14/0x40 [ 28.985310] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 28.991614] [] ? remove_wait_queue+0x14/0x40 [ 28.997652] [] remove_wait_queue+0x14/0x40 [ 29.003526] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 29.010509] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 29.017764] [] ? ep_free+0x1c0/0x1c0 [ 29.023106] [] ep_free+0x93/0x1c0 [ 29.028176] [] ? ep_free+0x1c0/0x1c0 [ 29.033515] [] ep_eventpoll_release+0x44/0x60 [ 29.039636] [] __fput+0x233/0x6d0 [ 29.044707] [] ____fput+0x15/0x20 [ 29.049779] [] task_work_run+0x104/0x180 [ 29.055460] [] do_exit+0x871/0x2a20 [ 29.060704] [] ? release_task+0x1240/0x1240 [ 29.066656] [] ? SyS_epoll_create+0x190/0x190 [ 29.072779] [] do_group_exit+0x108/0x320 [ 29.078460] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 29.084946] [] SyS_exit_group+0x1d/0x20 [ 29.090545] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 29.097093] [ 29.098692] Allocated by task 3316: [ 29.102285] [] save_stack_trace+0x26/0x50 [ 29.108183] [] save_stack+0x43/0xd0 [ 29.113548] [] kasan_kmalloc+0xad/0xe0 [ 29.119171] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 29.125755] [] binder_get_thread+0x181/0x7a0 [ 29.131912] [] binder_poll+0x4a/0x210 [ 29.137471] [] SyS_epoll_ctl+0x10b1/0x2050 [ 29.143463] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 29.150353] [ 29.151953] Freed by task 3316: [ 29.155204] [] save_stack_trace+0x26/0x50 [ 29.161095] [] save_stack+0x43/0xd0 [ 29.166461] [] kasan_slab_free+0x72/0xc0 [ 29.172259] [] kfree+0xfc/0x300 [ 29.177274] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 29.184032] [] binder_thread_release+0x27d/0x540 [ 29.190524] [] binder_ioctl+0xb94/0x12e0 [ 29.196319] [] do_vfs_ioctl+0x7aa/0xee0 [ 29.202039] [] SyS_ioctl+0x8f/0xc0 [ 29.207312] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 29.213986] [ 29.215585] The buggy address belongs to the object at ffff8801cfc18780 [ 29.215585] which belongs to the cache kmalloc-512 of size 512 [ 29.228209] The buggy address is located 184 bytes inside of [ 29.228209] 512-byte region [ffff8801cfc18780, ffff8801cfc18980) [ 29.240051] The buggy address belongs to the page: [ 30.701811] PANIC: double fault, error_code: 0x0 [ 30.706616] CPU: 1 PID: 3316 Comm: syzkaller004132 Not tainted 4.4.112-gd96d95d #31 [ 30.714388] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.723714] task: ffff8800b5755f00 task.stack: ffff8801d04b8000 [ 30.729738] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 30.738598] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 30.744017] RAX: ffff8800b5755f00 RBX: ffffea00073f0600 RCX: ffffffff8148fea0 [ 30.751266] RDX: 0000000000000000 RSI: ffffffff838a8620 RDI: ffffea00073f0600 [ 30.758508] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 30.765748] R10: 0000000000000002 R11: fffffbfff0ad7a1e R12: 0000000000000000 [ 30.772988] R13: ffffffff838a8620 R14: 0000000000000000 R15: 0000000000000000 [ 30.780232] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 30.788428] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 30.794288] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 30.801533] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 30.808789] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 30.816028] Stack: [ 30.818154] [ 30.819753] Call Trace: [ 30.822306] [ 30.824342] 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 [ 30.851304] Kernel panic - not syncing: Machine halted. [ 30.856648] CPU: 1 PID: 3316 Comm: syzkaller004132 Not tainted 4.4.112-gd96d95d #31 [ 30.864669] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.873993] 0000000000000000 e04b3d39d611006d ffff8801db30ce38 ffffffff81d054ed [ 30.881965] ffffffff83836a60 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 30.889951] 0000000000000000 ffff8801db30cf00 ffffffff81419dca 0000000041b58ab3 [ 30.897934] Call Trace: [ 30.900486] <#DF> [] dump_stack+0xc1/0x124 [ 30.906572] [] panic+0x1aa/0x388 [ 30.911554] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 30.918452] [] ? vprintk_emit+0x242/0x850 [ 30.924227] [] ? dump_page_badflags+0x2f/0x250 [ 30.930433] [] ? vprintk_emit+0x242/0x850 [ 30.936204] [] df_debug+0x2d/0x30 [ 30.941297] [] do_double_fault+0x10b/0x210 [ 30.947158] [] double_fault+0x2d/0x40 [ 30.952587] [] ? dump_page_badflags+0x180/0x250 [ 30.958884] [] ? dump_page_badflags+0x1a/0x250 [ 30.965084] <> [ 30.968469] Dumping ftrace buffer: [ 30.972274] (ftrace buffer empty) [ 30.975955] Kernel Offset: disabled [ 30.979552] Rebooting in 86400 seconds..