[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 33.324357][ T25] audit: type=1800 audit(1571320034.377:25): pid=7050 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 33.354719][ T25] audit: type=1800 audit(1571320034.377:26): pid=7050 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 33.381014][ T25] audit: type=1800 audit(1571320034.377:27): pid=7050 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 '10.128.0.57' (ECDSA) to the list of known hosts. 2019/10/17 13:47:21 fuzzer started 2019/10/17 13:47:23 dialing manager at 10.128.0.105:33899 2019/10/17 13:47:23 syscalls: 2524 2019/10/17 13:47:23 code coverage: enabled 2019/10/17 13:47:23 comparison tracing: enabled 2019/10/17 13:47:23 extra coverage: extra coverage is not supported by the kernel 2019/10/17 13:47:23 setuid sandbox: enabled 2019/10/17 13:47:23 namespace sandbox: enabled 2019/10/17 13:47:23 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/17 13:47:23 fault injection: enabled 2019/10/17 13:47:23 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/17 13:47:23 net packet injection: enabled 2019/10/17 13:47:23 net device setup: enabled 2019/10/17 13:47:23 concurrency sanitizer: enabled syzkaller login: [ 42.293375][ T7222] ================================================================== [ 42.301515][ T7222] BUG: KCSAN: data-race in tcp_poll / tcp_recvmsg [ 42.307912][ T7222] [ 42.310230][ T7222] read to 0xffff888128c70ebc of 4 bytes by task 7208 on cpu 0: [ 42.317754][ T7222] tcp_poll+0x1cc/0x6b0 [ 42.321891][ T7222] sock_poll+0xed/0x250 [ 42.326022][ T7222] ep_item_poll.isra.0+0x90/0x190 [ 42.331029][ T7222] ep_send_events_proc+0x113/0x590 [ 42.336115][ T7222] ep_scan_ready_list.constprop.0+0x189/0x500 [ 42.342155][ T7222] ep_poll+0xe3/0x900 [ 42.346112][ T7222] do_epoll_wait+0x162/0x180 [ 42.350675][ T7222] __x64_sys_epoll_pwait+0xcd/0x180 [ 42.355849][ T7222] do_syscall_64+0xcc/0x370 [ 42.360327][ T7222] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 42.366188][ T7222] [ 42.368498][ T7222] write to 0xffff888128c70ebc of 4 bytes by task 7222 on cpu 1: [ 42.376111][ T7222] tcp_recvmsg+0xd86/0x1a30 [ 42.380594][ T7222] inet_recvmsg+0xbb/0x250 [ 42.385000][ T7222] sock_recvmsg+0x92/0xb0 [ 42.389358][ T7222] sock_read_iter+0x15f/0x1e0 [ 42.394015][ T7222] new_sync_read+0x389/0x4f0 [ 42.398579][ T7222] __vfs_read+0xb1/0xc0 [ 42.402742][ T7222] vfs_read+0x143/0x2c0 [ 42.406873][ T7222] ksys_read+0xd5/0x1b0 [ 42.411021][ T7222] __x64_sys_read+0x4c/0x60 [ 42.415505][ T7222] do_syscall_64+0xcc/0x370 [ 42.419982][ T7222] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 42.425843][ T7222] [ 42.428144][ T7222] Reported by Kernel Concurrency Sanitizer on: [ 42.434275][ T7222] CPU: 1 PID: 7222 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 42.441698][ T7222] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.451735][ T7222] ================================================================== [ 42.459801][ T7222] Kernel panic - not syncing: panic_on_warn set ... [ 42.466362][ T7222] CPU: 1 PID: 7222 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 42.473786][ T7222] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.483812][ T7222] Call Trace: [ 42.487085][ T7222] dump_stack+0xf5/0x159 [ 42.491304][ T7222] panic+0x210/0x640 [ 42.495180][ T7222] ? __x64_sys_read+0x4c/0x60 [ 42.499870][ T7222] ? vprintk_func+0x8d/0x140 [ 42.504493][ T7222] kcsan_report.cold+0xc/0x1b [ 42.509149][ T7222] __kcsan_setup_watchpoint+0x3ee/0x510 [ 42.514678][ T7222] __tsan_write4+0x32/0x40 [ 42.519072][ T7222] tcp_recvmsg+0xd86/0x1a30 [ 42.523558][ T7222] ? __kcsan_setup_watchpoint+0x96/0x510 [ 42.529168][ T7222] inet_recvmsg+0xbb/0x250 [ 42.533563][ T7222] ? __tsan_read8+0x2c/0x30 [ 42.539342][ T7222] ? inet_sendpage+0x100/0x100 [ 42.544437][ T7222] sock_recvmsg+0x92/0xb0 [ 42.548747][ T7222] sock_read_iter+0x15f/0x1e0 [ 42.553414][ T7222] new_sync_read+0x389/0x4f0 [ 42.557982][ T7222] __vfs_read+0xb1/0xc0 [ 42.562120][ T7222] vfs_read+0x143/0x2c0 [ 42.566259][ T7222] ksys_read+0xd5/0x1b0 [ 42.570395][ T7222] __x64_sys_read+0x4c/0x60 [ 42.574878][ T7222] do_syscall_64+0xcc/0x370 [ 42.579370][ T7222] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 42.585254][ T7222] RIP: 0033:0x47c530 [ 42.589129][ T7222] 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 [ 42.608714][ T7222] RSP: 002b:000000c4202fb7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 42.617100][ T7222] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 42.625055][ T7222] RDX: 0000000000001000 RSI: 000000c4200d6000 RDI: 0000000000000003 [ 42.633000][ T7222] RBP: 000000c4202fb830 R08: 0000000000000000 R09: 0000000000000000 [ 42.640948][ T7222] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000004 [ 42.648939][ T7222] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 42.658254][ T7222] Kernel Offset: disabled [ 42.662574][ T7222] Rebooting in 86400 seconds..