[ OK ] Started OpenBSD Secure Shell server. [ 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 '10.128.0.233' (ECDSA) to the list of known hosts. 2021/04/26 23:31:05 fuzzer started 2021/04/26 23:31:06 dialing manager at 10.128.0.163:45437 2021/04/26 23:31:06 syscalls: 1982 2021/04/26 23:31:06 code coverage: enabled 2021/04/26 23:31:06 comparison tracing: enabled 2021/04/26 23:31:06 extra coverage: enabled 2021/04/26 23:31:06 setuid sandbox: enabled 2021/04/26 23:31:06 namespace sandbox: enabled 2021/04/26 23:31:06 Android sandbox: enabled 2021/04/26 23:31:06 fault injection: enabled 2021/04/26 23:31:06 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2021/04/26 23:31:06 net packet injection: /dev/net/tun does not exist 2021/04/26 23:31:06 net device setup: enabled 2021/04/26 23:31:06 concurrency sanitizer: enabled 2021/04/26 23:31:06 devlink PCI setup: PCI device 0000:00:10.0 is not available 2021/04/26 23:31:06 USB emulation: /dev/raw-gadget does not exist 2021/04/26 23:31:06 hci packet injection: /dev/vhci does not exist 2021/04/26 23:31:06 wifi device emulation: /sys/class/mac80211_hwsim/ does not exist 2021/04/26 23:31:06 802.15.4 emulation: /sys/bus/platform/devices/mac802154_hwsim does not exist 2021/04/26 23:31:07 suppressing KCSAN reports in functions: 'n_tty_receive_buf_common' 'ext4_mark_iloc_dirty' '__xa_clear_mark' 'ext4_free_inodes_count' 'do_signal_stop' '__add_to_page_cache_locked' 'fast_dput' '__process_echoes' 'ext4_sync_file' 'generic_write_end' 'hrtimer_interrupt' 'xas_clear_mark' 'shmem_mknod' 'step_into' 'audit_log_start' 'do_sys_poll' 'do_exit' '__send_signal' 'dd_has_work' '__ext4_new_inode' 'blk_mq_sched_dispatch_requests' 'do_select' '__mark_inode_dirty' 'ext4_set_iomap' 'expire_timers' 'unix_dgram_poll' 'blk_mq_rq_ctx_init' 'do_readlinkat' 'tick_sched_timer' 'tick_nohz_next_event' 'ext4_writepages' 'ext4_free_inode' 'blk_mq_dispatch_rq_list' 'kauditd_thread' 'exit_mm' '__xa_set_mark' 'shmem_add_to_page_cache' 2021/04/26 23:31:07 fetching corpus: 48, signal 12330/14220 (executing program) 2021/04/26 23:31:07 fetching corpus: 98, signal 23955/27548 (executing program) 2021/04/26 23:31:07 fetching corpus: 148, signal 30956/36188 (executing program) 2021/04/26 23:31:07 fetching corpus: 198, signal 35741/42583 (executing program) 2021/04/26 23:31:07 fetching corpus: 248, signal 41027/49358 (executing program) syzkaller login: [ 21.032759][ T1735] ================================================================== [ 21.034209][ T1735] BUG: KCSAN: data-race in futex_wait_queue_me / prepare_signal [ 21.035452][ T1735] [ 21.035781][ T1735] write to 0xffff888100b580ac of 4 bytes by task 1737 on cpu 0: [ 21.039774][ T1735] futex_wait_queue_me+0x198/0x260 [ 21.040615][ T1735] futex_wait+0x143/0x430 [ 21.041364][ T1735] do_futex+0x9e8/0x1e10 [ 21.041946][ T1735] __se_sys_futex+0x2a8/0x390 [ 21.042682][ T1735] __x64_sys_futex+0x74/0x80 [ 21.043365][ T1735] do_syscall_64+0x34/0x50 [ 21.044153][ T1735] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 21.044983][ T1735] [ 21.045322][ T1735] read to 0xffff888100b580ac of 4 bytes by task 1735 on cpu 1: [ 21.046374][ T1735] prepare_signal+0x872/0xd80 [ 21.047028][ T1735] __send_signal+0x64/0x760 [ 21.047641][ T1735] send_signal+0x38e/0x3d0 [ 21.048240][ T1735] do_send_specific+0x13d/0x1c0 [ 21.048906][ T1735] __x64_sys_tgkill+0x108/0x140 [ 21.049566][ T1735] do_syscall_64+0x34/0x50 [ 21.050180][ T1735] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 21.050988][ T1735] [ 21.051316][ T1735] Reported by Kernel Concurrency Sanitizer on: [ 21.052143][ T1735] CPU: 1 PID: 1735 Comm: syz-fuzzer Not tainted 5.12.0-syzkaller #0 [ 21.055456][ T1735] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 21.065484][ T1735] ================================================================== 2021/04/26 23:31:08 fetching corpus: 298, signal 45108/54928 (executing program) 2021/04/26 23:31:08 fetching corpus: 348, signal 47750/59070 (executing program) 2021/04/26 23:31:08 fetching corpus: 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