[ 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 '10.128.0.10' (ECDSA) to the list of known hosts. 2021/03/23 16:03:16 fuzzer started 2021/03/23 16:03:16 dialing manager at 10.128.0.163:41767 2021/03/23 16:03:20 syscalls: 3557 2021/03/23 16:03:20 code coverage: enabled 2021/03/23 16:03:20 comparison tracing: enabled 2021/03/23 16:03:20 extra coverage: enabled 2021/03/23 16:03:20 setuid sandbox: enabled 2021/03/23 16:03:20 namespace sandbox: enabled 2021/03/23 16:03:20 Android sandbox: /sys/fs/selinux/policy does not exist 2021/03/23 16:03:20 fault injection: enabled 2021/03/23 16:03:20 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2021/03/23 16:03:20 net packet injection: enabled 2021/03/23 16:03:20 net device setup: enabled 2021/03/23 16:03:20 concurrency sanitizer: enabled 2021/03/23 16:03:20 devlink PCI setup: PCI device 0000:00:10.0 is not available 2021/03/23 16:03:20 USB emulation: enabled 2021/03/23 16:03:20 hci packet injection: enabled 2021/03/23 16:03:20 wifi device emulation: enabled 2021/03/23 16:03:20 802.15.4 emulation: enabled 2021/03/23 16:03:22 suppressing KCSAN reports in functions: '__ext4_new_inode' 'shmem_file_read_iter' 'expire_timers' 'check_kill_permission' 'blk_mq_rq_ctx_init' 'ext4_free_inode' 'wbt_done' 'tick_nohz_next_event' 'generic_write_end' 'n_tty_receive_buf_common' 'dd_has_work' '__mark_inode_dirty' 'ext4_mark_iloc_dirty' 'blk_mq_dispatch_rq_list' 'xas_clear_mark' 'pcpu_alloc' 'wbt_issue' 'do_signal_stop' 'ext4_mb_regular_allocator' 'ext4_free_inodes_count' '__xa_clear_mark' 'audit_log_start' 'alloc_pid' '__filemap_fdatawrite_range' '__wb_update_bandwidth' 2021/03/23 16:03:22 fetching corpus: 0, signal 0/2000 (executing program) 2021/03/23 16:03:22 fetching corpus: 47, signal 22183/25935 (executing program) syzkaller login: [ 35.030929][ T8359] ================================================================== [ 35.039131][ T8359] BUG: KCSAN: data-race in complete_signal / futex_wait_queue_me [ 35.046828][ T8359] [ 35.049130][ T8359] write to 0xffff888105d3902c of 4 bytes by task 8366 on cpu 0: [ 35.056817][ T8359] futex_wait_queue_me+0x186/0x250 [ 35.062165][ T8359] futex_wait+0x145/0x400 [ 35.066579][ T8359] do_futex+0x1062/0x1cd0 [ 35.071347][ T8359] __se_sys_futex+0x2a8/0x390 [ 35.076198][ T8359] __x64_sys_futex+0x74/0x80 [ 35.080926][ T8359] do_syscall_64+0x39/0x80 [ 35.085334][ T8359] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 35.091440][ T8359] [ 35.093767][ T8359] read to 0xffff888105d3902c of 4 bytes by task 8359 on cpu 1: [ 35.101386][ T8359] complete_signal+0x7c/0x600 [ 35.106066][ T8359] __send_signal+0x662/0x780 [ 35.110632][ T8359] send_signal+0x398/0x3e0 [ 35.115031][ T8359] do_send_sig_info+0x9b/0xe0 [ 35.119685][ T8359] do_send_specific+0xc7/0x100 [ 35.124446][ T8359] __x64_sys_tgkill+0x108/0x140 2021/03/23 16:03:22 fetching corpus: 97, signal 34751/40221 (executing program) [ 35.129276][ T8359] do_syscall_64+0x39/0x80 [ 35.133672][ T8359] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 35.139541][ T8359] [ 35.141839][ T8359] Reported by Kernel Concurrency Sanitizer on: [ 35.147959][ T8359] CPU: 1 PID: 8359 Comm: syz-fuzzer Not tainted 5.12.0-rc4-syzkaller #0 [ 35.156345][ T8359] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.166375][ T8359] ================================================================== 2021/03/23 16:03:22 fetching corpus: 147, signal 45037/52069 (executing program) 2021/03/23 16:03:22 fetching corpus: 195, signal 55651/64203 (executing program) 2021/03/23 16:03:22 fetching corpus: 245, signal 64403/74370 (executing program) 2021/03/23 16:03:23 fetching corpus: 295, signal 71669/83029 (executing program) 2021/03/23 16:03:23 fetching corpus: 345, signal 76677/89472 (executing program) 2021/03/23 16:03:23 fetching corpus: 395, signal 80933/95122 (executing program) 2021/03/23 16:03:23 fetching corpus: 445, signal 85167/100690 (executing program) 2021/03/23 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