[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 40.346544][ T25] audit: type=1800 audit(1571565019.518:25): pid=7124 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 40.397911][ T25] audit: type=1800 audit(1571565019.518:26): pid=7124 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 40.426533][ T25] audit: type=1800 audit(1571565019.518:27): pid=7124 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2469 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.10.5' (ECDSA) to the list of known hosts. 2019/10/20 09:50:29 fuzzer started 2019/10/20 09:50:31 dialing manager at 10.128.0.105:43535 2019/10/20 09:50:31 syscalls: 2524 2019/10/20 09:50:31 code coverage: enabled 2019/10/20 09:50:31 comparison tracing: enabled 2019/10/20 09:50:31 extra coverage: extra coverage is not supported by the kernel 2019/10/20 09:50:31 setuid sandbox: enabled 2019/10/20 09:50:31 namespace sandbox: enabled 2019/10/20 09:50:31 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/20 09:50:31 fault injection: enabled 2019/10/20 09:50:31 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/20 09:50:31 net packet injection: enabled 2019/10/20 09:50:31 net device setup: enabled 2019/10/20 09:50:31 concurrency sanitizer: enabled syzkaller login: [ 52.617237][ T7280] ================================================================== [ 52.625627][ T7280] BUG: KCSAN: data-race in tcp_poll / tcp_recvmsg [ 52.632024][ T7280] [ 52.634343][ T7280] write to 0xffff8881256005bc of 4 bytes by task 7293 on cpu 0: [ 52.641961][ T7280] tcp_recvmsg+0xd86/0x1a30 [ 52.646636][ T7280] inet_recvmsg+0xbb/0x250 [ 52.651360][ T7280] sock_recvmsg+0x92/0xb0 [ 52.655748][ T7280] sock_read_iter+0x15f/0x1e0 [ 52.660608][ T7280] new_sync_read+0x389/0x4f0 [ 52.665237][ T7280] __vfs_read+0xb1/0xc0 [ 52.669672][ T7280] vfs_read+0x143/0x2c0 [ 52.673817][ T7280] ksys_read+0xd5/0x1b0 [ 52.677966][ T7280] __x64_sys_read+0x4c/0x60 [ 52.682604][ T7280] do_syscall_64+0xcc/0x370 [ 52.688400][ T7280] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 52.694619][ T7280] [ 52.696948][ T7280] read to 0xffff8881256005bc of 4 bytes by task 7280 on cpu 1: [ 52.704666][ T7280] tcp_poll+0x1cc/0x6b0 [ 52.708811][ T7280] sock_poll+0xed/0x250 [ 52.712959][ T7280] ep_item_poll.isra.0+0x90/0x190 [ 52.717971][ T7280] ep_send_events_proc+0x113/0x590 [ 52.723069][ T7280] ep_scan_ready_list.constprop.0+0x189/0x500 [ 52.729210][ T7280] ep_poll+0xe3/0x900 [ 52.733179][ T7280] do_epoll_wait+0x162/0x180 [ 52.737861][ T7280] __x64_sys_epoll_pwait+0xcd/0x180 [ 52.743064][ T7280] do_syscall_64+0xcc/0x370 [ 52.747578][ T7280] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 52.753470][ T7280] [ 52.755799][ T7280] Reported by Kernel Concurrency Sanitizer on: [ 52.762114][ T7280] CPU: 1 PID: 7280 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 52.769548][ T7280] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.779595][ T7280] ================================================================== [ 52.787642][ T7280] Kernel panic - not syncing: panic_on_warn set ... [ 52.794216][ T7280] CPU: 1 PID: 7280 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 52.801658][ T7280] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.811700][ T7280] Call Trace: [ 52.814990][ T7280] dump_stack+0xf5/0x159 [ 52.819227][ T7280] panic+0x210/0x640 [ 52.823118][ T7280] ? do_syscall_64+0xcc/0x370 [ 52.827798][ T7280] ? vprintk_func+0x8d/0x140 [ 52.832998][ T7280] kcsan_report.cold+0xc/0x10 [ 52.837753][ T7280] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 52.843292][ T7280] __tsan_read4+0x2c/0x30 [ 52.847618][ T7280] tcp_poll+0x1cc/0x6b0 [ 52.851867][ T7280] ? tcp_alloc_md5sig_pool+0x320/0x320 [ 52.857315][ T7280] sock_poll+0xed/0x250 [ 52.861476][ T7280] ? sock_read_iter+0x1e0/0x1e0 [ 52.866324][ T7280] ep_item_poll.isra.0+0x90/0x190 [ 52.871346][ T7280] ep_send_events_proc+0x113/0x590 [ 52.876460][ T7280] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 52.882091][ T7280] ep_scan_ready_list.constprop.0+0x189/0x500 [ 52.888498][ T7280] ? ep_loop_check_proc+0x2f0/0x2f0 [ 52.893704][ T7280] ep_poll+0xe3/0x900 [ 52.897692][ T7280] ? __fget+0xb8/0x1d0 [ 52.901757][ T7280] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 52.907377][ T7280] ? __fget_light+0xaf/0x190 [ 52.911960][ T7280] do_epoll_wait+0x162/0x180 [ 52.916551][ T7280] __x64_sys_epoll_pwait+0xcd/0x180 [ 52.921744][ T7280] do_syscall_64+0xcc/0x370 [ 52.926242][ T7280] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 52.932120][ T7280] RIP: 0033:0x45b300 [ 52.936010][ T7280] Code: 0f 05 89 44 24 20 c3 cc cc cc 8b 7c 24 08 48 8b 74 24 10 8b 54 24 18 44 8b 54 24 1c 49 c7 c0 00 00 00 00 b8 19 01 00 00 0f 05 <89> 44 24 20 c3 cc cc cc cc cc cc cc cc cc cc cc 8b 7c 24 08 48 c7 [ 52.955691][ T7280] RSP: 002b:000000c42004f8d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 [ 52.964099][ T7280] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045b300 [ 52.972060][ T7280] RDX: 0000000000000080 RSI: 000000c42004f918 RDI: 0000000000000004 [ 52.980455][ T7280] RBP: 000000c42004ff18 R08: 0000000000000000 R09: 0000000000002544 [ 52.988428][ T7280] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000042f0a0 [ 52.996412][ T7280] R13: 00000000000000f1 R14: 0000000000000011 R15: 0000000000000000 [ 53.006010][ T7280] Kernel Offset: disabled [ 53.010333][ T7280] Rebooting in 86400 seconds..