[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.502358][ T25] audit: type=1800 audit(1571791566.533:25): pid=7116 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.537047][ T25] audit: type=1800 audit(1571791566.533:26): pid=7116 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.558760][ T25] audit: type=1800 audit(1571791566.533:27): pid=7116 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 '10.128.0.88' (ECDSA) to the list of known hosts. 2019/10/23 00:46:17 fuzzer started 2019/10/23 00:46:19 dialing manager at 10.128.0.105:33369 2019/10/23 00:46:19 syscalls: 2524 2019/10/23 00:46:19 code coverage: enabled 2019/10/23 00:46:19 comparison tracing: enabled 2019/10/23 00:46:19 extra coverage: extra coverage is not supported by the kernel 2019/10/23 00:46:19 setuid sandbox: enabled 2019/10/23 00:46:19 namespace sandbox: enabled 2019/10/23 00:46:19 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/23 00:46:19 fault injection: enabled 2019/10/23 00:46:19 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/23 00:46:19 net packet injection: enabled 2019/10/23 00:46:19 net device setup: enabled 2019/10/23 00:46:19 concurrency sanitizer: enabled syzkaller login: [ 48.977433][ T7284] ================================================================== [ 48.985847][ T7284] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 48.994013][ T7284] [ 48.996452][ T7284] write to 0xffff8881265312ec of 4 bytes by interrupt on cpu 1: [ 49.004421][ T7284] tcp_add_backlog+0x4a0/0xcc0 [ 49.009469][ T7284] tcp_v4_rcv+0x1a60/0x1bb0 [ 49.014258][ T7284] ip_protocol_deliver_rcu+0x4d/0x420 [ 49.019986][ T7284] ip_local_deliver_finish+0x110/0x140 [ 49.028052][ T7284] ip_local_deliver+0x133/0x210 [ 49.033536][ T7284] ip_rcv_finish+0x121/0x160 [ 49.038944][ T7284] ip_rcv+0x18f/0x1a0 [ 49.043064][ T7284] __netif_receive_skb_one_core+0xa7/0xe0 [ 49.049132][ T7284] __netif_receive_skb+0x37/0xf0 [ 49.055385][ T7284] netif_receive_skb_internal+0x59/0x190 [ 49.061819][ T7284] napi_gro_receive+0x28f/0x330 [ 49.067636][ T7284] receive_buf+0x284/0x30b0 [ 49.073146][ T7284] virtnet_poll+0x436/0x7d0 [ 49.077838][ T7284] net_rx_action+0x3ae/0xa90 [ 49.082499][ T7284] [ 49.085373][ T7284] read to 0xffff8881265312ec of 4 bytes by task 7284 on cpu 0: [ 49.099560][ T7284] tcp_grow_window.isra.0+0x6b/0x480 [ 49.105175][ T7284] tcp_event_data_recv+0x68f/0x990 [ 49.110476][ T7284] tcp_rcv_established+0xbfe/0xf50 [ 49.116012][ T7284] tcp_v4_do_rcv+0x381/0x4e0 [ 49.120828][ T7284] __release_sock+0x135/0x1e0 [ 49.125589][ T7284] release_sock+0x61/0x160 [ 49.130814][ T7284] tcp_recvmsg+0x63b/0x1a30 [ 49.136229][ T7284] inet_recvmsg+0xbb/0x250 [ 49.141110][ T7284] sock_recvmsg+0x92/0xb0 [ 49.147128][ T7284] sock_read_iter+0x15f/0x1e0 [ 49.152457][ T7284] new_sync_read+0x389/0x4f0 [ 49.158883][ T7284] __vfs_read+0xb1/0xc0 [ 49.163701][ T7284] vfs_read+0x143/0x2c0 [ 49.168972][ T7284] [ 49.171539][ T7284] Reported by Kernel Concurrency Sanitizer on: [ 49.178134][ T7284] CPU: 0 PID: 7284 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 49.185900][ T7284] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.196158][ T7284] ================================================================== [ 49.204686][ T7284] Kernel panic - not syncing: panic_on_warn set ... [ 49.211538][ T7284] CPU: 0 PID: 7284 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 49.219097][ T7284] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.229688][ T7284] Call Trace: [ 49.233723][ T7284] dump_stack+0xf5/0x159 [ 49.238652][ T7284] panic+0x210/0x640 [ 49.242695][ T7284] ? sock_recvmsg+0x92/0xb0 [ 49.247444][ T7284] ? vprintk_func+0x8d/0x140 [ 49.252737][ T7284] kcsan_report.cold+0xc/0x10 [ 49.258422][ T7284] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 49.267365][ T7284] __tsan_read4+0x2c/0x30 [ 49.272474][ T7284] tcp_grow_window.isra.0+0x6b/0x480 [ 49.278204][ T7284] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 49.284453][ T7284] tcp_event_data_recv+0x68f/0x990 [ 49.289830][ T7284] tcp_rcv_established+0xbfe/0xf50 [ 49.295062][ T7284] ? ipv4_dst_check+0xc6/0xf0 [ 49.300411][ T7284] tcp_v4_do_rcv+0x381/0x4e0 [ 49.305109][ T7284] __release_sock+0x135/0x1e0 [ 49.310128][ T7284] release_sock+0x61/0x160 [ 49.314857][ T7284] tcp_recvmsg+0x63b/0x1a30 [ 49.319773][ T7284] inet_recvmsg+0xbb/0x250 [ 49.324422][ T7284] ? __tsan_read8+0x2c/0x30 [ 49.329374][ T7284] ? inet_sendpage+0x100/0x100 [ 49.334562][ T7284] sock_recvmsg+0x92/0xb0 [ 49.339190][ T7284] sock_read_iter+0x15f/0x1e0 [ 49.344144][ T7284] new_sync_read+0x389/0x4f0 [ 49.349288][ T7284] __vfs_read+0xb1/0xc0 [ 49.353768][ T7284] vfs_read+0x143/0x2c0 [ 49.358055][ T7284] ksys_read+0xd5/0x1b0 [ 49.362693][ T7284] __x64_sys_read+0x4c/0x60 [ 49.367330][ T7284] do_syscall_64+0xcc/0x370 [ 49.371950][ T7284] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.377827][ T7284] RIP: 0033:0x47c530 [ 49.389798][ T7284] 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 [ 49.410321][ T7284] RSP: 002b:000000c4203bd8b8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 49.418927][ T7284] RAX: ffffffffffffffda RBX: 000000c4202fd800 RCX: 000000000047c530 [ 49.427380][ T7284] RDX: 0000000000001000 RSI: 000000c4202fa000 RDI: 0000000000000003 [ 49.435860][ T7284] RBP: 000000c4203bd910 R08: 0000000000000000 R09: 0000000000000000 [ 49.444264][ T7284] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000280 [ 49.452588][ T7284] R13: 00000000000000ff R14: 00007f0715f396c8 R15: 0000000000000020 [ 49.463332][ T7284] Kernel Offset: disabled [ 49.467991][ T7284] Rebooting in 86400 seconds..