[ 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 '10.128.1.47' (ECDSA) to the list of known hosts. 2021/04/04 22:28:24 fuzzer started 2021/04/04 22:28:24 dialing manager at 10.128.0.163:38329 2021/04/04 22:28:28 syscalls: 3557 2021/04/04 22:28:28 code coverage: enabled 2021/04/04 22:28:28 comparison tracing: enabled 2021/04/04 22:28:28 extra coverage: enabled 2021/04/04 22:28:28 setuid sandbox: enabled 2021/04/04 22:28:28 namespace sandbox: enabled 2021/04/04 22:28:28 Android sandbox: /sys/fs/selinux/policy does not exist 2021/04/04 22:28:28 fault injection: enabled 2021/04/04 22:28:28 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2021/04/04 22:28:28 net packet injection: enabled 2021/04/04 22:28:28 net device setup: enabled 2021/04/04 22:28:28 concurrency sanitizer: enabled 2021/04/04 22:28:28 devlink PCI setup: PCI device 0000:00:10.0 is not available 2021/04/04 22:28:28 USB emulation: enabled 2021/04/04 22:28:28 hci packet injection: enabled 2021/04/04 22:28:28 wifi device emulation: enabled 2021/04/04 22:28:28 802.15.4 emulation: enabled 2021/04/04 22:28:29 suppressing KCSAN reports in functions: '__xa_clear_mark' '__filemap_fdatawrite_range' 'exit_mm' '__ext4_new_inode' 'ext4_ext_try_to_merge_right' 'do_signal_stop' 'ext4_free_inode' 'kauditd_thread' 'ext4_mpage_readpages' 'alloc_pid' 'generic_write_end' 'blk_mq_rq_ctx_init' 'blk_mq_dispatch_rq_list' 'blk_mq_sched_dispatch_requests' 'wbt_done' 'ext4_free_inodes_count' '__add_to_page_cache_locked' 2021/04/04 22:28:29 fetching corpus: 0, signal 0/2000 (executing program) syzkaller login: [ 34.187096][ T8346] ================================================================== [ 34.195172][ T8346] BUG: KCSAN: data-race in __send_signal / futex_wait_queue_me [ 34.202816][ T8346] [ 34.205118][ T8346] write to 0xffff8881024e802c of 4 bytes by task 8351 on cpu 0: [ 34.212733][ T8346] futex_wait_queue_me+0x186/0x250 [ 34.217819][ T8346] futex_wait+0x145/0x400 [ 34.222123][ T8346] do_futex+0x1062/0x1cd0 [ 34.226449][ T8346] __se_sys_futex+0x2a8/0x390 [ 34.231118][ T8346] __x64_sys_futex+0x74/0x80 [ 34.235705][ T8346] do_syscall_64+0x39/0x80 [ 34.240094][ T8346] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 34.245963][ T8346] [ 34.248275][ T8346] read to 0xffff8881024e802c of 4 bytes by task 8346 on cpu 1: [ 34.255785][ T8346] __send_signal+0x27f/0x790 [ 34.260347][ T8346] send_signal+0x398/0x3e0 [ 34.264735][ T8346] do_send_sig_info+0x9b/0xe0 [ 34.269412][ T8346] do_send_specific+0xc7/0x100 [ 34.274147][ T8346] __x64_sys_tgkill+0x108/0x140 [ 34.278976][ T8346] do_syscall_64+0x39/0x80 2021/04/04 22:28:29 fetching corpus: 48, signal 17378/21116 (executing program) [ 34.283366][ T8346] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 34.289251][ T8346] [ 34.291551][ T8346] Reported by Kernel Concurrency Sanitizer on: [ 34.297669][ T8346] CPU: 1 PID: 8346 Comm: syz-fuzzer Not tainted 5.12.0-rc6-syzkaller #0 [ 34.305967][ T8346] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.315996][ T8346] ================================================================== 2021/04/04 22:28:30 fetching corpus: 98, signal 27130/32518 (executing program) 2021/04/04 22:28:30 fetching corpus: 146, signal 40025/46875 (executing program) 2021/04/04 22:28:30 fetching corpus: 195, signal 51144/59347 (executing program) 2021/04/04 22:28:30 fetching corpus: 245, signal 58645/68151 (executing program) 2021/04/04 22:28:30 fetching corpus: 295, signal 63957/74802 (executing program) 2021/04/04 22:28:31 fetching corpus: 345, signal 70102/82175 (executing program) 2021/04/04 22:28:31 fetching corpus: 394, signal 74118/87488 (executing program) 2021/04/04 22:28:31 fetching corpus: 444, signal 78623/93182 (executing program) 2021/04/04 22:28:31 fetching corpus: 493, signal 83621/99285 (executing program) 2021/04/04 22:28:31 fetching corpus: 543, signal 86332/103226 (executing program) 2021/04/04 22:28:31 fetching corpus: 593, signal 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