[ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.10.58' (ECDSA) to the list of known hosts. 2020/07/13 15:08:00 fuzzer started 2020/07/13 15:08:00 dialing manager at 10.128.0.105:38995 2020/07/13 15:08:00 syscalls: 3150 2020/07/13 15:08:00 code coverage: enabled 2020/07/13 15:08:00 comparison tracing: enabled 2020/07/13 15:08:00 extra coverage: enabled 2020/07/13 15:08:00 setuid sandbox: enabled 2020/07/13 15:08:00 namespace sandbox: enabled 2020/07/13 15:08:00 Android sandbox: /sys/fs/selinux/policy does not exist 2020/07/13 15:08:00 fault injection: enabled 2020/07/13 15:08:00 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2020/07/13 15:08:00 net packet injection: enabled 2020/07/13 15:08:00 net device setup: enabled 2020/07/13 15:08:00 concurrency sanitizer: enabled 2020/07/13 15:08:00 devlink PCI setup: PCI device 0000:00:10.0 is not available 2020/07/13 15:08:00 USB emulation: enabled 2020/07/13 15:08:04 suppressing KCSAN reports in functions: 'wbt_issue' 'xas_find_marked' 'alloc_pid' '__ext4_new_inode' 'n_tty_receive_buf_common' '__delayacct_blkio_end' 'do_syslog' '__blkdev_get' 'generic_file_buffered_read' '__xa_clear_mark' 'dd_has_work' 'exit_signals' 'do_epoll_wait' 'af_alg_sendpage' 'wg_packet_decrypt_worker' 'ext4_mark_iloc_dirty' 'do_select' '__delete_from_page_cache' 'snd_seq_check_queue' 'shmem_file_read_iter' 'find_get_pages_range_tag' 'page_counter_charge' 'do_nanosleep' 'pcpu_alloc' 'blk_mq_sched_dispatch_requests' 'blk_mq_dispatch_rq_list' 'futex_wait_queue_me' 'kauditd_thread' 'tick_nohz_next_event' '__add_to_page_cache_locked' 'step_into' 'ext4_free_inode' 'generic_write_end' 'blk_mq_rq_ctx_init' 'exit_mm' 'ext4_writepages' 'expire_timers' 'xas_clear_mark' '__blkdev_put' 'fsnotify' 'shmem_getpage_gfp' 'do_sys_poll' 'ext4_free_inodes_count' '__ext4_update_other_inode_time' syzkaller login: [ 90.474629][ T8644] ================================================================== [ 90.482836][ T8644] BUG: KCSAN: data-race in __mod_timer / timer_clear_idle [ 90.489913][ T8644] [ 90.492231][ T8644] write to 0xffff88812c01cb24 of 1 bytes by task 0 on cpu 0: [ 90.499575][ T8644] timer_clear_idle+0x2e/0x40 [ 90.504231][ T8644] tick_nohz_idle_retain_tick+0x3e/0x40 [ 90.509776][ T8644] do_idle+0x287/0x310 [ 90.514785][ T8644] cpu_startup_entry+0x15/0x20 [ 90.519522][ T8644] rest_init+0xd8/0xe0 [ 90.523579][ T8644] arch_call_rest_init+0xa/0xb [ 90.528329][ T8644] start_kernel+0x608/0x6d0 [ 90.532814][ T8644] secondary_startup_64+0xa4/0xb0 [ 90.537802][ T8644] [ 90.540109][ T8644] read to 0xffff88812c01cb24 of 1 bytes by task 8644 on cpu 1: [ 90.547637][ T8644] __mod_timer+0xa24/0xf00 [ 90.552035][ T8644] mod_timer+0x1b/0x20 [ 90.556084][ T8644] sk_reset_timer+0x1f/0xa0 [ 90.560557][ T8644] tcp_rearm_rto+0x204/0x210 [ 90.565119][ T8644] tcp_write_xmit+0x1bee/0x3f40 [ 90.569938][ T8644] __tcp_push_pending_frames+0x68/0x1c0 [ 90.575629][ T8644] tcp_push+0x2da/0x2f0 [ 90.580535][ T8644] tcp_sendmsg_locked+0x1bf9/0x2200 [ 90.585698][ T8644] tcp_sendmsg+0x2c/0x40 [ 90.589910][ T8644] inet_sendmsg+0x5f/0x80 [ 90.594230][ T8644] sock_write_iter+0x1a1/0x200 [ 90.598966][ T8644] vfs_write+0x607/0x690 [ 90.603187][ T8644] ksys_write+0xce/0x180 [ 90.607409][ T8644] __x64_sys_write+0x3e/0x50 [ 90.611966][ T8644] do_syscall_64+0x51/0xb0 [ 90.616351][ T8644] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 90.622212][ T8644] [ 90.624507][ T8644] Reported by Kernel Concurrency Sanitizer on: [ 90.630630][ T8644] CPU: 1 PID: 8644 Comm: syz-fuzzer Not tainted 5.8.0-rc5-syzkaller #0 [ 90.638836][ T8644] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 90.648875][ T8644] ================================================================== [ 90.657034][ T8644] Kernel panic - not syncing: panic_on_warn set ... [ 90.663599][ T8644] CPU: 1 PID: 8644 Comm: syz-fuzzer Not tainted 5.8.0-rc5-syzkaller #0 [ 90.672407][ T8644] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 90.682435][ T8644] Call Trace: [ 90.685699][ T8644] dump_stack+0x10f/0x19d [ 90.689996][ T8644] panic+0x207/0x64a [ 90.693874][ T8644] ? vprintk_emit+0x44a/0x4f0 [ 90.698534][ T8644] kcsan_report+0x684/0x690 [ 90.703017][ T8644] ? kcsan_setup_watchpoint+0x453/0x4d0 [ 90.708549][ T8644] ? __mod_timer+0xa24/0xf00 [ 90.713106][ T8644] ? mod_timer+0x1b/0x20 [ 90.717313][ T8644] ? sk_reset_timer+0x1f/0xa0 [ 90.721961][ T8644] ? tcp_rearm_rto+0x204/0x210 [ 90.726691][ T8644] ? tcp_write_xmit+0x1bee/0x3f40 [ 90.731689][ T8644] ? __tcp_push_pending_frames+0x68/0x1c0 [ 90.737389][ T8644] ? tcp_push+0x2da/0x2f0 [ 90.741704][ T8644] ? tcp_sendmsg_locked+0x1bf9/0x2200 [ 90.747041][ T8644] ? tcp_sendmsg+0x2c/0x40 [ 90.751438][ T8644] ? inet_sendmsg+0x5f/0x80 [ 90.755921][ T8644] ? sock_write_iter+0x1a1/0x200 [ 90.760838][ T8644] ? vfs_write+0x607/0x690 [ 90.765222][ T8644] ? ksys_write+0xce/0x180 [ 90.769605][ T8644] ? __x64_sys_write+0x3e/0x50 [ 90.774374][ T8644] ? do_syscall_64+0x51/0xb0 [ 90.778967][ T8644] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 90.785034][ T8644] ? __ip_queue_xmit+0x9ba/0x9e0 [ 90.789943][ T8644] ? __copy_skb_header+0x228/0x270 [ 90.795033][ T8644] kcsan_setup_watchpoint+0x453/0x4d0 [ 90.800374][ T8644] __mod_timer+0xa24/0xf00 [ 90.804771][ T8644] mod_timer+0x1b/0x20 [ 90.809241][ T8644] sk_reset_timer+0x1f/0xa0 [ 90.813724][ T8644] tcp_rearm_rto+0x204/0x210 [ 90.818281][ T8644] tcp_write_xmit+0x1bee/0x3f40 [ 90.823106][ T8644] ? handle_fasteoi_nmi+0x290/0x290 [ 90.828277][ T8644] ? check_preemption_disabled+0x51/0x140 [ 90.833964][ T8644] ? iov_iter_advance+0x1e0/0x890 [ 90.838957][ T8644] ? _copy_from_iter_full+0x1d9/0x6d0 [ 90.844309][ T8644] __tcp_push_pending_frames+0x68/0x1c0 [ 90.849842][ T8644] tcp_push+0x2da/0x2f0 [ 90.853991][ T8644] tcp_sendmsg_locked+0x1bf9/0x2200 [ 90.859173][ T8644] tcp_sendmsg+0x2c/0x40 [ 90.863383][ T8644] inet_sendmsg+0x5f/0x80 [ 90.867732][ T8644] sock_write_iter+0x1a1/0x200 [ 90.872468][ T8644] vfs_write+0x607/0x690 [ 90.878082][ T8644] ksys_write+0xce/0x180 [ 90.882309][ T8644] __x64_sys_write+0x3e/0x50 [ 90.886882][ T8644] do_syscall_64+0x51/0xb0 [ 90.892267][ T8644] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 90.898147][ T8644] RIP: 0033:0x4b3cdb [ 90.902008][ T8644] Code: Bad RIP value. [ 90.906052][ T8644] RSP: 002b:000000c00c593540 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 [ 90.914465][ T8644] RAX: ffffffffffffffda RBX: 000000c00002e800 RCX: 00000000004b3cdb [ 90.922488][ T8644] RDX: 0000000000000007 RSI: 000000c00000a200 RDI: 0000000000000006 [ 90.930548][ T8644] RBP: 000000c00c593590 R08: 000000c00000a201 R09: 0000000000000007 [ 90.938510][ T8644] R10: 000000c000114000 R11: 0000000000000202 R12: 000000000000011e [ 90.946452][ T8644] R13: 000000c0004a2000 R14: 0000000000000007 R15: 000000000000666c [ 92.010388][ T8644] Shutting down cpus with NMI [ 92.016302][ T8644] Kernel Offset: disabled [ 92.020610][ T8644] Rebooting in 86400 seconds..