[ 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 '10.128.0.83' (ECDSA) to the list of known hosts. 2020/06/27 20:05:33 fuzzer started 2020/06/27 20:05:33 dialing manager at 10.128.0.105:44595 2020/06/27 20:05:34 syscalls: 3105 2020/06/27 20:05:34 code coverage: enabled 2020/06/27 20:05:34 comparison tracing: enabled 2020/06/27 20:05:34 extra coverage: enabled 2020/06/27 20:05:34 setuid sandbox: enabled 2020/06/27 20:05:34 namespace sandbox: enabled 2020/06/27 20:05:34 Android sandbox: /sys/fs/selinux/policy does not exist 2020/06/27 20:05:34 fault injection: enabled 2020/06/27 20:05:34 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2020/06/27 20:05:34 net packet injection: enabled 2020/06/27 20:05:34 net device setup: enabled 2020/06/27 20:05:34 concurrency sanitizer: enabled 2020/06/27 20:05:34 devlink PCI setup: PCI device 0000:00:10.0 is not available 2020/06/27 20:05:34 USB emulation: enabled 2020/06/27 20:05:34 suppressing KCSAN reports in functions: '__ext4_new_inode' 'copy_process' 'n_tty_receive_buf_common' 'blk_mq_sched_dispatch_requests' 'ext4_free_inode' 'page_counter_charge' '__delayacct_blkio_end' 'ext4_free_inodes_count' 'pcpu_alloc' 'blk_mq_rq_ctx_init' 'generic_write_end' 'do_epoll_wait' syzkaller login: [ 35.530387][ T8624] ================================================================== [ 35.538477][ T8624] BUG: KCSAN: data-race in __mod_timer / timer_clear_idle [ 35.545611][ T8624] [ 35.547916][ T8624] write to 0xffff88812c01cb24 of 1 bytes by task 0 on cpu 0: [ 35.556039][ T8624] timer_clear_idle+0x2e/0x40 [ 35.560688][ T8624] tick_nohz_idle_retain_tick+0x3e/0x40 [ 35.566203][ T8624] do_idle+0x287/0x310 [ 35.570241][ T8624] cpu_startup_entry+0x15/0x20 [ 35.575059][ T8624] rest_init+0xd8/0xe0 [ 35.579097][ T8624] arch_call_rest_init+0xa/0xb [ 35.583862][ T8624] start_kernel+0x608/0x6d0 [ 35.588334][ T8624] secondary_startup_64+0xa4/0xb0 [ 35.593351][ T8624] [ 35.595650][ T8624] read to 0xffff88812c01cb24 of 1 bytes by task 8624 on cpu 1: [ 35.603156][ T8624] __mod_timer+0xb87/0xf00 [ 35.607536][ T8624] mod_timer+0x1b/0x20 [ 35.611572][ T8624] sk_reset_timer+0x1f/0xa0 [ 35.616042][ T8624] tcp_rearm_rto+0x204/0x210 [ 35.620597][ T8624] tcp_write_xmit+0x1bee/0x3f30 [ 35.625412][ T8624] __tcp_push_pending_frames+0x68/0x1c0 [ 35.630923][ T8624] tcp_push+0x2c4/0x2e0 [ 35.635045][ T8624] tcp_sendmsg_locked+0x1b90/0x2180 [ 35.640312][ T8624] tcp_sendmsg+0x2c/0x40 [ 35.644520][ T8624] inet_sendmsg+0x5f/0x80 [ 35.648817][ T8624] sock_write_iter+0x1a1/0x200 [ 35.653549][ T8624] __vfs_write+0x2d8/0x340 [ 35.657956][ T8624] vfs_write+0x19b/0x350 [ 35.662189][ T8624] ksys_write+0xce/0x180 [ 35.666413][ T8624] __x64_sys_write+0x3e/0x50 [ 35.670971][ T8624] do_syscall_64+0x71/0x120 [ 35.675449][ T8624] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 35.681309][ T8624] [ 35.683605][ T8624] Reported by Kernel Concurrency Sanitizer on: [ 35.689725][ T8624] CPU: 1 PID: 8624 Comm: syz-fuzzer Not tainted 5.8.0-rc2-syzkaller #0 [ 35.697926][ T8624] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.707951][ T8624] ================================================================== [ 35.715980][ T8624] Kernel panic - not syncing: panic_on_warn set ... [ 35.722542][ T8624] CPU: 1 PID: 8624 Comm: syz-fuzzer Not tainted 5.8.0-rc2-syzkaller #0 [ 35.730749][ T8624] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.740774][ T8624] Call Trace: [ 35.744043][ T8624] dump_stack+0x10f/0x19d [ 35.748342][ T8624] panic+0x1f8/0x63a [ 35.752205][ T8624] ? vprintk_emit+0x44a/0x4f0 [ 35.756852][ T8624] kcsan_report+0x684/0x690 [ 35.761325][ T8624] ? kcsan_setup_watchpoint+0x453/0x4d0 [ 35.766837][ T8624] ? __mod_timer+0xb87/0xf00 [ 35.771393][ T8624] ? mod_timer+0x1b/0x20 [ 35.775603][ T8624] ? sk_reset_timer+0x1f/0xa0 [ 35.780246][ T8624] ? tcp_rearm_rto+0x204/0x210 [ 35.784978][ T8624] ? tcp_write_xmit+0x1bee/0x3f30 [ 35.789969][ T8624] ? __tcp_push_pending_frames+0x68/0x1c0 [ 35.795653][ T8624] ? tcp_push+0x2c4/0x2e0 [ 35.799948][ T8624] ? tcp_sendmsg_locked+0x1b90/0x2180 [ 35.805284][ T8624] ? tcp_sendmsg+0x2c/0x40 [ 35.809667][ T8624] ? inet_sendmsg+0x5f/0x80 [ 35.814140][ T8624] ? sock_write_iter+0x1a1/0x200 [ 35.819042][ T8624] ? __vfs_write+0x2d8/0x340 [ 35.823603][ T8624] ? vfs_write+0x19b/0x350 [ 35.827985][ T8624] ? ksys_write+0xce/0x180 [ 35.832366][ T8624] ? __x64_sys_write+0x3e/0x50 [ 35.837107][ T8624] ? do_syscall_64+0x71/0x120 [ 35.841750][ T8624] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 35.847786][ T8624] ? __ip_queue_xmit+0x99e/0x9c0 [ 35.852693][ T8624] ? check_preemption_disabled+0x3f/0x1a0 [ 35.858397][ T8624] kcsan_setup_watchpoint+0x453/0x4d0 [ 35.863737][ T8624] __mod_timer+0xb87/0xf00 [ 35.868119][ T8624] mod_timer+0x1b/0x20 [ 35.872159][ T8624] sk_reset_timer+0x1f/0xa0 [ 35.876630][ T8624] tcp_rearm_rto+0x204/0x210 [ 35.881186][ T8624] tcp_write_xmit+0x1bee/0x3f30 [ 35.886011][ T8624] ? check_preemption_disabled+0x8f/0x1a0 [ 35.891694][ T8624] ? iov_iter_advance+0x1e0/0x890 [ 35.896687][ T8624] ? _copy_from_iter_full+0x1d9/0x6d0 [ 35.902036][ T8624] ? __virt_addr_valid+0x15a/0x1a0 [ 35.907114][ T8624] __tcp_push_pending_frames+0x68/0x1c0 [ 35.912625][ T8624] tcp_push+0x2c4/0x2e0 [ 35.916747][ T8624] tcp_sendmsg_locked+0x1b90/0x2180 [ 35.921915][ T8624] tcp_sendmsg+0x2c/0x40 [ 35.926125][ T8624] inet_sendmsg+0x5f/0x80 [ 35.930423][ T8624] sock_write_iter+0x1a1/0x200 [ 35.935152][ T8624] ? do_numa_page+0x540/0x670 [ 35.939795][ T8624] __vfs_write+0x2d8/0x340 [ 35.944181][ T8624] vfs_write+0x19b/0x350 [ 35.948390][ T8624] ksys_write+0xce/0x180 [ 35.952603][ T8624] __x64_sys_write+0x3e/0x50 [ 35.957157][ T8624] do_syscall_64+0x71/0x120 [ 35.961629][ T8624] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 35.967485][ T8624] RIP: 0033:0x4b3cdb [ 35.971342][ T8624] Code: Bad RIP value. [ 35.975373][ T8624] RSP: 002b:000000c000bb3540 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 [ 35.983745][ T8624] RAX: ffffffffffffffda RBX: 000000c00002e800 RCX: 00000000004b3cdb [ 35.991695][ T8624] RDX: 0000000000000008 RSI: 000000c00000a200 RDI: 0000000000000006 [ 35.999653][ T8624] RBP: 000000c000bb3590 R08: 000000c00000a201 R09: 0000000000000008 [ 36.007591][ T8624] R10: 000000c000112000 R11: 0000000000000202 R12: 000000000000011e [ 36.015529][ T8624] R13: 000000c000346000 R14: 0000000000000007 R15: 0000000000001b0e [ 37.124422][ T8624] Shutting down cpus with NMI [ 37.130166][ T8624] Kernel Offset: disabled [ 37.134472][ T8624] Rebooting in 86400 seconds..