[ 15.712483] random: sshd: uninitialized urandom read (32 bytes read, 31 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: [ 20.194858] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 20.553135] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 21.338485] random: sshd: uninitialized urandom read (32 bytes read, 84 bits of entropy available) [ 34.834902] random: sshd: uninitialized urandom read (32 bytes read, 97 bits of entropy available) Warning: Permanently added '10.128.0.63' (ECDSA) to the list of known hosts. [ 40.846063] random: sshd: uninitialized urandom read (32 bytes read, 103 bits of entropy available) executing program [ 40.942457] ================================================================== [ 40.949866] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 40.959211] Read of size 8 at addr ffff8800b4ada838 by task syzkaller859173/3323 [ 40.966733] [ 40.968354] CPU: 0 PID: 3323 Comm: syzkaller859173 Not tainted 4.4.111-g1849cd3 #26 [ 40.978339] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.988014] 0000000000000000 13245db47fc0f493 ffff8801d2fff8d0 ffffffff81d0509d [ 40.996381] ffffea0002d2b680 ffff8800b4ada838 0000000000000000 ffff8800b4ada838 [ 41.004385] 0000000000000000 ffff8801d2fff908 ffffffff814fd433 ffff8800b4ada838 [ 41.012362] Call Trace: [ 41.014925] [] dump_stack+0xc1/0x124 [ 41.021748] [] print_address_description+0x73/0x260 [ 41.028819] [] kasan_report+0x285/0x370 [ 41.034424] [] ? __lock_acquire+0x387e/0x4b50 [ 41.040634] [] __asan_report_load8_noabort+0x14/0x20 [ 41.047450] [] __lock_acquire+0x387e/0x4b50 [ 41.053401] [] ? __lock_acquire+0xb5f/0x4b50 [ 41.059429] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 41.066419] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 41.073422] [] ? mark_held_locks+0xaf/0x100 [ 41.079886] [] lock_acquire+0x15e/0x460 [ 41.085581] [] ? remove_wait_queue+0x14/0x40 [ 41.091621] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 41.098434] [] ? remove_wait_queue+0x14/0x40 [ 41.104464] [] remove_wait_queue+0x14/0x40 [ 41.110330] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 41.117331] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 41.124599] [] ? ep_free+0x1c0/0x1c0 [ 41.129934] [] ep_free+0x93/0x1c0 [ 41.135009] [] ? ep_free+0x1c0/0x1c0 [ 41.140342] [] ep_eventpoll_release+0x44/0x60 [ 41.146462] [] __fput+0x233/0x6d0 [ 41.151546] [] ____fput+0x15/0x20 [ 41.156624] [] task_work_run+0x104/0x180 [ 41.162310] [] do_exit+0x871/0x2a20 [ 41.167557] [] ? release_task+0x1240/0x1240 [ 41.173499] [] ? SyS_epoll_create+0x190/0x190 [ 41.179626] [] do_group_exit+0x108/0x320 [ 41.185309] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 41.193160] [] SyS_exit_group+0x1d/0x20 [ 41.198756] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 41.205303] [ 41.206900] Allocated by task 3323: [ 41.210493] [] save_stack_trace+0x26/0x50 [ 41.216382] [] save_stack+0x43/0xd0 [ 41.221760] [] kasan_kmalloc+0xad/0xe0 [ 41.227398] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 41.234686] [] binder_get_thread+0x181/0x7a0 [ 41.241954] [] binder_poll+0x4a/0x210 [ 41.247766] [] SyS_epoll_ctl+0x10b1/0x2050 [ 41.253749] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 41.260680] [ 41.262811] Freed by task 3323: [ 41.266493] [] save_stack_trace+0x26/0x50 [ 41.272822] [] save_stack+0x43/0xd0 [ 41.278214] [] kasan_slab_free+0x72/0xc0 [ 41.284544] [] kfree+0xfc/0x300 [ 41.289844] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 41.296603] [] binder_thread_release+0x27d/0x540 [ 41.304229] [] binder_ioctl+0xb94/0x12e0 [ 41.310040] [] do_vfs_ioctl+0x7aa/0xee0 [ 41.315771] [] SyS_ioctl+0x8f/0xc0 [ 41.321060] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 41.328425] [ 41.330637] The buggy address belongs to the object at ffff8800b4ada780 [ 41.330637] which belongs to the cache kmalloc-512 of size 512 [ 41.343438] The buggy address is located 184 bytes inside of [ 41.343438] 512-byte region [ffff8800b4ada780, ffff8800b4ada980) [ 41.356411] The buggy address belongs to the page: [ 42.786540] PANIC: double fault, error_code: 0x0 [ 42.791589] CPU: 0 PID: 0 Comm: €兑 Not tainted 4.4.111-g1849cd3 #26 [ 42.798846] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.808530] task: ffff8801d2ff0000 task.stack: ffffea0002d2b680 [ 42.814559] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 42.823408] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 42.830129] RAX: ffff8801d2ff0000 RBX: ffffea0002d2b680 RCX: ffffffff8148f980 [ 42.837373] RDX: 0000000000000000 RSI: ffffffff838a8360 RDI: ffffea0002d2b680 [ 42.844623] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 42.851874] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 42.859132] R13: ffffffff838a8360 R14: 0000000000000000 R15: 0000000000000000 [ 42.866396] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 42.874614] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 42.880467] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 42.887712] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 42.895054] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 42.902314] Stack: [ 42.904432] [ 42.906030] Call Trace: [ 42.908584] [ 42.910614] 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 [ 42.937729] Kernel panic - not syncing: Machine halted. [ 42.943078] CPU: 0 PID: 0 Comm: €兑 Not tainted 4.4.111-g1849cd3 #26 [ 42.949627] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.958968] 0000000000000000 13245db47fc0f493 ffff8801db20ce38 ffffffff81d0509d [ 42.966953] ffffffff838367c0 ffff8801db20cf10 ffffffff83808040 ffff880100000000 [ 42.974966] 0000000000000000 ffff8801db20cf00 ffffffff81419a3a 0000000041b58ab3 [ 42.982944] Call Trace: [ 42.985516] <#DF> [] dump_stack+0xc1/0x124 [ 42.991610] [] panic+0x1aa/0x388 [ 42.996651] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 43.003549] [] ? vprintk_emit+0x242/0x850 [ 43.009320] [] ? dump_page_badflags+0x2f/0x250 [ 43.015540] [] ? vprintk_emit+0x242/0x850 [ 43.021486] [] df_debug+0x2d/0x30 [ 43.026574] [] do_double_fault+0x10b/0x210 [ 43.032441] [] double_fault+0x2d/0x40 [ 43.037870] [] ? dump_page_badflags+0x180/0x250 [ 43.044161] [] ? dump_page_badflags+0x1a/0x250 [ 43.050880] <> [ 43.054299] Dumping ftrace buffer: [ 43.058195] (ftrace buffer empty) [ 43.061888] Kernel Offset: disabled [ 43.065526] Rebooting in 86400 seconds..