[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 40.320509][ T26] audit: type=1800 audit(1571309753.858:25): pid=7136 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 40.340281][ T26] audit: type=1800 audit(1571309753.858:26): pid=7136 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 40.361974][ T26] audit: type=1800 audit(1571309753.858:27): pid=7136 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 '10.128.1.30' (ECDSA) to the list of known hosts. 2019/10/17 10:56:04 fuzzer started 2019/10/17 10:56:06 dialing manager at 10.128.0.105:33899 2019/10/17 10:56:06 syscalls: 2524 2019/10/17 10:56:06 code coverage: enabled 2019/10/17 10:56:06 comparison tracing: enabled 2019/10/17 10:56:06 extra coverage: extra coverage is not supported by the kernel 2019/10/17 10:56:06 setuid sandbox: enabled 2019/10/17 10:56:06 namespace sandbox: enabled 2019/10/17 10:56:06 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/17 10:56:06 fault injection: enabled 2019/10/17 10:56:06 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/17 10:56:06 net packet injection: enabled 2019/10/17 10:56:06 net device setup: enabled 2019/10/17 10:56:06 concurrency sanitizer: enabled syzkaller login: [ 53.374242][ T7288] ================================================================== [ 53.382361][ T7288] BUG: KCSAN: data-race in tcp_poll / tcp_recvmsg [ 53.389278][ T7288] [ 53.391650][ T7288] read to 0xffff888126bee5bc of 4 bytes by task 7289 on cpu 0: [ 53.399171][ T7288] tcp_poll+0x1cc/0x6b0 [ 53.403320][ T7288] sock_poll+0xed/0x250 [ 53.407454][ T7288] ep_item_poll.isra.0+0x90/0x190 [ 53.412453][ T7288] ep_send_events_proc+0x113/0x590 [ 53.417640][ T7288] ep_scan_ready_list.constprop.0+0x189/0x500 [ 53.423684][ T7288] ep_poll+0xe3/0x900 [ 53.427642][ T7288] do_epoll_wait+0x162/0x180 [ 53.432274][ T7288] __x64_sys_epoll_pwait+0xcd/0x180 [ 53.437454][ T7288] do_syscall_64+0xcc/0x370 [ 53.441947][ T7288] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 53.447810][ T7288] [ 53.450227][ T7288] write to 0xffff888126bee5bc of 4 bytes by task 7288 on cpu 1: [ 53.457842][ T7288] tcp_recvmsg+0xd86/0x1a30 [ 53.462960][ T7288] inet_recvmsg+0xbb/0x250 [ 53.467354][ T7288] sock_recvmsg+0x92/0xb0 [ 53.471761][ T7288] sock_read_iter+0x15f/0x1e0 [ 53.476418][ T7288] new_sync_read+0x389/0x4f0 [ 53.480993][ T7288] __vfs_read+0xb1/0xc0 [ 53.485127][ T7288] vfs_read+0x143/0x2c0 [ 53.489295][ T7288] ksys_read+0xd5/0x1b0 [ 53.493440][ T7288] __x64_sys_read+0x4c/0x60 [ 53.497934][ T7288] do_syscall_64+0xcc/0x370 [ 53.502424][ T7288] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 53.508292][ T7288] [ 53.510599][ T7288] Reported by Kernel Concurrency Sanitizer on: [ 53.516727][ T7288] CPU: 1 PID: 7288 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 53.524156][ T7288] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.534217][ T7288] ================================================================== [ 53.542341][ T7288] Kernel panic - not syncing: panic_on_warn set ... [ 53.548918][ T7288] CPU: 1 PID: 7288 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 53.556345][ T7288] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.566375][ T7288] Call Trace: [ 53.569646][ T7288] dump_stack+0xf5/0x159 [ 53.573866][ T7288] panic+0x210/0x640 [ 53.577739][ T7288] ? __x64_sys_read+0x4c/0x60 [ 53.582415][ T7288] ? vprintk_func+0x8d/0x140 [ 53.586999][ T7288] kcsan_report.cold+0xc/0x1b [ 53.591682][ T7288] __kcsan_setup_watchpoint+0x3ee/0x510 [ 53.597217][ T7288] __tsan_write4+0x32/0x40 [ 53.601612][ T7288] tcp_recvmsg+0xd86/0x1a30 [ 53.606096][ T7288] ? __kcsan_setup_watchpoint+0x96/0x510 [ 53.611720][ T7288] inet_recvmsg+0xbb/0x250 [ 53.616111][ T7288] ? __tsan_read8+0x2c/0x30 [ 53.621373][ T7288] ? inet_sendpage+0x100/0x100 [ 53.626204][ T7288] sock_recvmsg+0x92/0xb0 [ 53.630514][ T7288] sock_read_iter+0x15f/0x1e0 [ 53.635172][ T7288] new_sync_read+0x389/0x4f0 [ 53.639749][ T7288] __vfs_read+0xb1/0xc0 [ 53.643900][ T7288] vfs_read+0x143/0x2c0 [ 53.648053][ T7288] ksys_read+0xd5/0x1b0 [ 53.652185][ T7288] __x64_sys_read+0x4c/0x60 [ 53.656682][ T7288] do_syscall_64+0xcc/0x370 [ 53.661162][ T7288] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 53.667026][ T7288] RIP: 0033:0x47c530 [ 53.670922][ T7288] Code: 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 49 c7 c2 00 00 00 00 49 c7 c0 00 00 00 00 49 c7 c1 00 00 00 00 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30 [ 53.690542][ T7288] RSP: 002b:000000c4204eb7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 53.699283][ T7288] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 53.707389][ T7288] RDX: 0000000000001000 RSI: 000000c4202be000 RDI: 0000000000000003 [ 53.715569][ T7288] RBP: 000000c4204eb830 R08: 0000000000000000 R09: 0000000000000000 [ 53.724228][ T7288] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000040 [ 53.732194][ T7288] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 53.741766][ T7288] Kernel Offset: disabled [ 53.748276][ T7288] Rebooting in 86400 seconds..