[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.901449][ T26] audit: type=1800 audit(1571778279.920:25): pid=6921 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.928334][ T26] audit: type=1800 audit(1571778279.920:26): pid=6921 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.967779][ T26] audit: type=1800 audit(1571778279.920:27): pid=6921 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 '10.128.0.216' (ECDSA) to the list of known hosts. 2019/10/22 21:04:51 fuzzer started 2019/10/22 21:04:52 dialing manager at 10.128.0.105:33369 2019/10/22 21:04:52 syscalls: 2524 2019/10/22 21:04:52 code coverage: enabled 2019/10/22 21:04:52 comparison tracing: enabled 2019/10/22 21:04:52 extra coverage: extra coverage is not supported by the kernel 2019/10/22 21:04:52 setuid sandbox: enabled 2019/10/22 21:04:52 namespace sandbox: enabled 2019/10/22 21:04:52 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 21:04:52 fault injection: enabled 2019/10/22 21:04:52 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 21:04:52 net packet injection: enabled 2019/10/22 21:04:52 net device setup: enabled 2019/10/22 21:04:52 concurrency sanitizer: enabled syzkaller login: [ 47.572632][ T7090] ================================================================== [ 47.580776][ T7090] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 47.588730][ T7090] [ 47.591033][ T7090] write to 0xffff888122a5f32c of 4 bytes by interrupt on cpu 0: [ 47.598650][ T7090] tcp_add_backlog+0x4a0/0xcc0 [ 47.603389][ T7090] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.607867][ T7090] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.613210][ T7090] ip_local_deliver_finish+0x110/0x140 [ 47.618670][ T7090] ip_local_deliver+0x133/0x210 [ 47.623493][ T7090] ip_rcv_finish+0x121/0x160 [ 47.628057][ T7090] ip_rcv+0x18f/0x1a0 [ 47.632012][ T7090] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.637737][ T7090] __netif_receive_skb+0x37/0xf0 [ 47.642648][ T7090] netif_receive_skb_internal+0x59/0x190 [ 47.648281][ T7090] napi_gro_receive+0x28f/0x330 [ 47.653106][ T7090] receive_buf+0x284/0x30b0 [ 47.657581][ T7090] virtnet_poll+0x436/0x7d0 [ 47.662058][ T7090] net_rx_action+0x3ae/0xa90 [ 47.666644][ T7090] [ 47.668983][ T7090] read to 0xffff888122a5f32c of 4 bytes by task 7090 on cpu 1: [ 47.676499][ T7090] tcp_grow_window.isra.0+0x6b/0x480 [ 47.681763][ T7090] tcp_event_data_recv+0x68f/0x990 [ 47.686846][ T7090] tcp_rcv_established+0xbfe/0xf50 [ 47.691930][ T7090] tcp_v4_do_rcv+0x381/0x4e0 [ 47.696495][ T7090] __release_sock+0x135/0x1e0 [ 47.701144][ T7090] release_sock+0x61/0x160 [ 47.705536][ T7090] tcp_recvmsg+0x63b/0x1a30 [ 47.710012][ T7090] inet_recvmsg+0xbb/0x250 [ 47.714402][ T7090] sock_recvmsg+0x92/0xb0 [ 47.718706][ T7090] sock_read_iter+0x15f/0x1e0 [ 47.723356][ T7090] new_sync_read+0x389/0x4f0 [ 47.727917][ T7090] __vfs_read+0xb1/0xc0 [ 47.732057][ T7090] vfs_read+0x143/0x2c0 [ 47.736183][ T7090] [ 47.738484][ T7090] Reported by Kernel Concurrency Sanitizer on: [ 47.744611][ T7090] CPU: 1 PID: 7090 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.752036][ T7090] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.762074][ T7090] ================================================================== [ 47.770118][ T7090] Kernel panic - not syncing: panic_on_warn set ... [ 47.776681][ T7090] CPU: 1 PID: 7090 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.784105][ T7090] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.794218][ T7090] Call Trace: [ 47.797485][ T7090] dump_stack+0xf5/0x159 [ 47.801705][ T7090] panic+0x210/0x640 [ 47.805579][ T7090] ? sock_recvmsg+0x92/0xb0 [ 47.810065][ T7090] ? vprintk_func+0x8d/0x140 [ 47.814632][ T7090] kcsan_report.cold+0xc/0x10 [ 47.819285][ T7090] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.824810][ T7090] __tsan_read4+0x2c/0x30 [ 47.829114][ T7090] tcp_grow_window.isra.0+0x6b/0x480 [ 47.834372][ T7090] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.839982][ T7090] tcp_event_data_recv+0x68f/0x990 [ 47.845070][ T7090] tcp_rcv_established+0xbfe/0xf50 [ 47.850201][ T7090] ? ipv4_dst_check+0xc6/0xf0 [ 47.854868][ T7090] tcp_v4_do_rcv+0x381/0x4e0 [ 47.859472][ T7090] __release_sock+0x135/0x1e0 [ 47.864128][ T7090] release_sock+0x61/0x160 [ 47.868524][ T7090] tcp_recvmsg+0x63b/0x1a30 [ 47.873011][ T7090] inet_recvmsg+0xbb/0x250 [ 47.877405][ T7090] ? __tsan_read8+0x2c/0x30 [ 47.881885][ T7090] ? inet_sendpage+0x100/0x100 [ 47.886628][ T7090] sock_recvmsg+0x92/0xb0 [ 47.890939][ T7090] sock_read_iter+0x15f/0x1e0 [ 47.895599][ T7090] new_sync_read+0x389/0x4f0 [ 47.900174][ T7090] __vfs_read+0xb1/0xc0 [ 47.904309][ T7090] vfs_read+0x143/0x2c0 [ 47.908444][ T7090] ksys_read+0xd5/0x1b0 [ 47.912580][ T7090] __x64_sys_read+0x4c/0x60 [ 47.917064][ T7090] do_syscall_64+0xcc/0x370 [ 47.921544][ T7090] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.927419][ T7090] RIP: 0033:0x47c530 [ 47.931294][ T7090] 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 [ 47.950871][ T7090] RSP: 002b:000000c4204e5810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 47.959257][ T7090] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.967204][ T7090] RDX: 0000000000001000 RSI: 000000c4203da000 RDI: 0000000000000003 [ 47.975148][ T7090] RBP: 000000c4204e5868 R08: 0000000000000000 R09: 0000000000000000 [ 47.983104][ T7090] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000100 [ 47.991049][ T7090] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 48.000281][ T7090] Kernel Offset: disabled [ 48.004595][ T7090] Rebooting in 86400 seconds..