[ 15.885938] 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: [ 21.266375] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 21.533769] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 22.475907] random: sshd: uninitialized urandom read (32 bytes read, 102 bits of entropy available) [ 32.300343] random: sshd: uninitialized urandom read (32 bytes read, 111 bits of entropy available) Warning: Permanently added '10.128.15.223' (ECDSA) to the list of known hosts. [ 37.761447] random: sshd: uninitialized urandom read (32 bytes read, 115 bits of entropy available) executing program [ 37.857995] ================================================================== [ 37.865391] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 37.872029] Read of size 8 at addr ffff8800b43b3738 by task syzkaller247740/3336 [ 37.879531] [ 37.881136] CPU: 0 PID: 3336 Comm: syzkaller247740 Not tainted 4.4.111-gc2f631b #27 [ 37.888897] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 37.898224] 0000000000000000 2eab600826aee4f7 ffff8801d026f8d0 ffffffff81d0513d [ 37.906198] ffffea0002d0ec80 ffff8800b43b3738 0000000000000000 ffff8800b43b3738 [ 37.914174] 0000000000000000 ffff8801d026f908 ffffffff814fd433 ffff8800b43b3738 [ 37.922148] Call Trace: [ 37.924713] [] dump_stack+0xc1/0x124 [ 37.930063] [] print_address_description+0x73/0x260 [ 37.936711] [] kasan_report+0x285/0x370 [ 37.942307] [] ? __lock_acquire+0x387e/0x4b50 [ 37.948430] [] __asan_report_load8_noabort+0x14/0x20 [ 37.955151] [] __lock_acquire+0x387e/0x4b50 [ 37.961093] [] ? __lock_acquire+0xb5f/0x4b50 [ 37.967118] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 37.974143] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 37.981224] [] ? mark_held_locks+0xaf/0x100 [ 37.987162] [] lock_acquire+0x15e/0x460 [ 37.992761] [] ? remove_wait_queue+0x14/0x40 [ 37.998790] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 38.005075] [] ? remove_wait_queue+0x14/0x40 [ 38.011105] [] remove_wait_queue+0x14/0x40 [ 38.016959] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 38.023942] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 38.031182] [] ? ep_free+0x1c0/0x1c0 [ 38.036511] [] ep_free+0x93/0x1c0 [ 38.041584] [] ? ep_free+0x1c0/0x1c0 [ 38.046916] [] ep_eventpoll_release+0x44/0x60 [ 38.053043] [] __fput+0x233/0x6d0 [ 38.058114] [] ____fput+0x15/0x20 [ 38.063187] [] task_work_run+0x104/0x180 [ 38.068865] [] do_exit+0x871/0x2a20 [ 38.074111] [] ? release_task+0x1240/0x1240 [ 38.080055] [] ? SyS_epoll_create+0x190/0x190 [ 38.086167] [] do_group_exit+0x108/0x320 [ 38.091858] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 38.098319] [] SyS_exit_group+0x1d/0x20 [ 38.103926] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 38.110470] [ 38.112068] Allocated by task 3336: [ 38.115665] [] save_stack_trace+0x26/0x50 [ 38.121551] [] save_stack+0x43/0xd0 [ 38.126926] [] kasan_kmalloc+0xad/0xe0 [ 38.132550] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 38.139131] [] binder_get_thread+0x181/0x7a0 [ 38.145293] [] binder_poll+0x4a/0x210 [ 38.150834] [] SyS_epoll_ctl+0x10b1/0x2050 [ 38.156806] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 38.163475] [ 38.165073] Freed by task 3336: [ 38.168316] [] save_stack_trace+0x26/0x50 [ 38.174203] [] save_stack+0x43/0xd0 [ 38.179569] [] kasan_slab_free+0x72/0xc0 [ 38.185377] [] kfree+0xfc/0x300 [ 38.190397] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 38.197149] [] binder_thread_release+0x27d/0x540 [ 38.203640] [] binder_ioctl+0xb94/0x12e0 [ 38.209440] [] do_vfs_ioctl+0x7aa/0xee0 [ 38.215151] [] SyS_ioctl+0x8f/0xc0 [ 38.220428] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 38.227096] [ 38.228695] The buggy address belongs to the object at ffff8800b43b3680 [ 38.228695] which belongs to the cache kmalloc-512 of size 512 [ 38.241320] The buggy address is located 184 bytes inside of [ 38.241320] 512-byte region [ffff8800b43b3680, ffff8800b43b3880) [ 38.253164] The buggy address belongs to the page: [ 38.266279] ------------[ cut here ]------------ [ 38.271061] WARNING: CPU: 1 PID: 0 at net/ipv4/tcp_input.c:1922 tcp_enter_loss+0xd26/0xfe0() [ 38.279779] Kernel panic - not syncing: panic_on_warn set ... [ 38.279779] [ 38.287125] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.111-gc2f631b #27 [ 38.294125] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.303451] 0000000000000000 24cff26414aa826e ffff8801db307a98 ffffffff81d0513d [ 38.311425] ffffffff83842f60 ffff8801db307b70 ffffffff83cee920 0000000000000009 [ 38.319396] 0000000000000782 ffff8801db307b60 ffffffff81419a3a 0000000041b58ab3 [ 38.327713] Call Trace: [ 38.330266] [] dump_stack+0xc1/0x124 [ 38.336339] [] panic+0x1aa/0x388 [ 38.341324] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 38.348220] [] ? pm_qos_get_value.part.4+0xb/0xb [ 38.354597] [] ? warn_slowpath_common+0x10a/0x140 [ 38.361058] [] warn_slowpath_common+0x125/0x140 [ 38.367348] [] ? tcp_enter_loss+0xd26/0xfe0 [ 38.373288] [] warn_slowpath_null+0x29/0x30 [ 38.379242] [] tcp_enter_loss+0xd26/0xfe0 [ 38.385009] [] tcp_retransmit_timer+0xa1d/0x1f10 [ 38.391383] [] tcp_write_timer_handler+0x21e/0x6d0 [ 38.398540] [] tcp_write_timer+0xa1/0xd0 [ 38.404226] [] call_timer_fn+0x18b/0x860 [ 38.409905] [] ? call_timer_fn+0xdc/0x860 [ 38.415671] [] ? tcp_write_timer_handler+0x6d0/0x6d0 [ 38.422398] [] ? process_timeout+0x20/0x20 [ 38.428251] [] ? _raw_spin_unlock_irq+0x27/0x50 [ 38.434540] [] ? tcp_write_timer_handler+0x6d0/0x6d0 [ 38.441261] [] ? trace_hardirqs_on_caller+0x266/0x590 [ 38.448068] [] ? tcp_write_timer_handler+0x6d0/0x6d0 [ 38.454791] [] run_timer_softirq+0x604/0xbb0 [ 38.460836] [] ? msleep+0xe0/0xe0 [ 38.465909] [] __do_softirq+0x24d/0xa59 [ 38.471502] [] irq_exit+0x119/0x140 [ 38.476749] [] smp_apic_timer_interrupt+0x7b/0xa0 [ 38.483211] [] apic_timer_interrupt+0xa0/0xb0 [ 38.489321] [] ? native_safe_halt+0x6/0x10 [ 38.495907] [] ? trace_hardirqs_on+0xd/0x10 [ 38.501862] [] default_idle+0x55/0x3c0 [ 38.507369] [] arch_cpu_idle+0xa/0x10 [ 38.512800] [] default_idle_call+0x48/0x70 [ 38.518654] [] cpu_startup_entry+0x605/0x820 [ 38.524680] [] ? call_cpuidle+0xe0/0xe0 [ 38.530278] [] ? clockevents_register_device+0x122/0x230 [ 38.537350] [] start_secondary+0x304/0x3e0 [ 38.543203] [] ? set_cpu_sibling_map+0x1040/0x1040 [ 39.609696] Shutting down cpus with NMI [ 39.614197] Dumping ftrace buffer: [ 39.617850] (ftrace buffer empty) [ 39.621535] Kernel Offset: disabled [ 39.625161] Rebooting in 86400 seconds..