[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 36.783264][ T26] audit: type=1800 audit(1571477806.476:25): pid=7118 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 36.819760][ T26] audit: type=1800 audit(1571477806.476:26): pid=7118 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 36.843530][ T26] audit: type=1800 audit(1571477806.476:27): pid=7118 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 '10.128.15.225' (ECDSA) to the list of known hosts. 2019/10/19 09:36:57 fuzzer started 2019/10/19 09:36:59 dialing manager at 10.128.0.105:43535 2019/10/19 09:36:59 syscalls: 2524 2019/10/19 09:36:59 code coverage: enabled 2019/10/19 09:36:59 comparison tracing: enabled 2019/10/19 09:36:59 extra coverage: extra coverage is not supported by the kernel 2019/10/19 09:36:59 setuid sandbox: enabled 2019/10/19 09:36:59 namespace sandbox: enabled 2019/10/19 09:36:59 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/19 09:36:59 fault injection: enabled 2019/10/19 09:36:59 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/19 09:36:59 net packet injection: enabled 2019/10/19 09:36:59 net device setup: enabled 2019/10/19 09:36:59 concurrency sanitizer: enabled syzkaller login: [ 49.876115][ T7273] ================================================================== [ 49.884241][ T7273] BUG: KCSAN: data-race in tcp_poll / tcp_recvmsg [ 49.890629][ T7273] [ 49.892949][ T7273] read to 0xffff888126ab2e7c of 4 bytes by task 7277 on cpu 1: [ 49.900478][ T7273] tcp_poll+0x1cc/0x6b0 [ 49.904639][ T7273] sock_poll+0xed/0x250 [ 49.908779][ T7273] ep_item_poll.isra.0+0x90/0x190 [ 49.913780][ T7273] ep_send_events_proc+0x113/0x590 [ 49.918868][ T7273] ep_scan_ready_list.constprop.0+0x189/0x500 [ 49.924910][ T7273] ep_poll+0xe3/0x900 [ 49.928917][ T7273] do_epoll_wait+0x162/0x180 [ 49.933487][ T7273] __x64_sys_epoll_pwait+0xcd/0x180 [ 49.938669][ T7273] do_syscall_64+0xcc/0x370 [ 49.943190][ T7273] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.949052][ T7273] [ 49.951359][ T7273] write to 0xffff888126ab2e7c of 4 bytes by task 7273 on cpu 0: [ 49.958969][ T7273] tcp_recvmsg+0xd86/0x1a30 [ 49.963450][ T7273] inet_recvmsg+0xbb/0x250 [ 49.967845][ T7273] sock_recvmsg+0x92/0xb0 [ 49.972160][ T7273] sock_read_iter+0x15f/0x1e0 [ 49.976814][ T7273] new_sync_read+0x389/0x4f0 [ 49.981394][ T7273] __vfs_read+0xb1/0xc0 [ 49.985525][ T7273] vfs_read+0x143/0x2c0 [ 49.989658][ T7273] ksys_read+0xd5/0x1b0 [ 49.993791][ T7273] __x64_sys_read+0x4c/0x60 [ 49.998283][ T7273] do_syscall_64+0xcc/0x370 [ 50.002763][ T7273] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 50.008639][ T7273] [ 50.010954][ T7273] Reported by Kernel Concurrency Sanitizer on: [ 50.017094][ T7273] CPU: 0 PID: 7273 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 50.024520][ T7273] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.034567][ T7273] ================================================================== [ 50.042604][ T7273] Kernel panic - not syncing: panic_on_warn set ... [ 50.049168][ T7273] CPU: 0 PID: 7273 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 50.056596][ T7273] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.066637][ T7273] Call Trace: [ 50.069913][ T7273] dump_stack+0xf5/0x159 [ 50.074135][ T7273] panic+0x210/0x640 [ 50.078009][ T7273] ? __x64_sys_read+0x4c/0x60 [ 50.082672][ T7273] ? vprintk_func+0x8d/0x140 [ 50.087252][ T7273] kcsan_report.cold+0xc/0x10 [ 50.091907][ T7273] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 50.097430][ T7273] __tsan_write4+0x32/0x40 [ 50.101830][ T7273] tcp_recvmsg+0xd86/0x1a30 [ 50.106336][ T7273] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 50.111956][ T7273] inet_recvmsg+0xbb/0x250 [ 50.116354][ T7273] ? __tsan_read8+0x2c/0x30 [ 50.120837][ T7273] ? inet_sendpage+0x100/0x100 [ 50.125580][ T7273] sock_recvmsg+0x92/0xb0 [ 50.129888][ T7273] sock_read_iter+0x15f/0x1e0 [ 50.134548][ T7273] new_sync_read+0x389/0x4f0 [ 50.139121][ T7273] __vfs_read+0xb1/0xc0 [ 50.143272][ T7273] vfs_read+0x143/0x2c0 [ 50.147435][ T7273] ksys_read+0xd5/0x1b0 [ 50.151572][ T7273] __x64_sys_read+0x4c/0x60 [ 50.156069][ T7273] do_syscall_64+0xcc/0x370 [ 50.160552][ T7273] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 50.166432][ T7273] RIP: 0033:0x47c530 [ 50.170315][ T7273] 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 [ 50.189913][ T7273] RSP: 002b:000000c4203997d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 50.198302][ T7273] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 50.206252][ T7273] RDX: 0000000000001000 RSI: 000000c42037e000 RDI: 0000000000000003 [ 50.214219][ T7273] RBP: 000000c420399830 R08: 0000000000000000 R09: 0000000000000000 [ 50.222171][ T7273] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000008 [ 50.230120][ T7273] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 50.239376][ T7273] Kernel Offset: disabled [ 50.243716][ T7273] Rebooting in 86400 seconds..