[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 43.074761][ T26] audit: type=1800 audit(1570998832.437:25): pid=7172 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 43.127521][ T26] audit: type=1800 audit(1570998832.437:26): pid=7172 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 43.154927][ T26] audit: type=1800 audit(1570998832.437:27): pid=7172 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 '10.128.0.195' (ECDSA) to the list of known hosts. 2019/10/13 20:34:04 fuzzer started 2019/10/13 20:34:05 dialing manager at 10.128.0.105:40973 2019/10/13 20:34:05 syscalls: 2523 2019/10/13 20:34:05 code coverage: enabled 2019/10/13 20:34:05 comparison tracing: enabled 2019/10/13 20:34:05 extra coverage: extra coverage is not supported by the kernel 2019/10/13 20:34:05 setuid sandbox: enabled 2019/10/13 20:34:05 namespace sandbox: enabled 2019/10/13 20:34:05 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/13 20:34:05 fault injection: enabled 2019/10/13 20:34:05 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/13 20:34:05 net packet injection: enabled 2019/10/13 20:34:05 net device setup: enabled 2019/10/13 20:34:05 concurrency sanitizer: enabled syzkaller login: [ 56.209016][ T7325] ================================================================== [ 56.217151][ T7325] BUG: KCSAN: data-race in __zone_watermark_ok / free_one_page [ 56.224678][ T7325] [ 56.227002][ T7325] read to 0xffff88812fffcf58 of 8 bytes by interrupt on cpu 0: [ 56.234545][ T7325] __zone_watermark_ok+0x106/0x240 [ 56.239666][ T7325] get_page_from_freelist+0x629/0x2300 [ 56.245133][ T7325] __alloc_pages_nodemask+0x255/0x4d0 [ 56.250491][ T7325] page_frag_alloc+0x11e/0x2d0 [ 56.255240][ T7325] __napi_alloc_skb+0x172/0x210 [ 56.260164][ T7325] page_to_skb+0x8d/0x480 [ 56.264478][ T7325] receive_buf+0x17c7/0x30b0 [ 56.269069][ T7325] virtnet_poll+0x436/0x7d0 [ 56.273556][ T7325] net_rx_action+0x3ae/0xa50 [ 56.278158][ T7325] __do_softirq+0x115/0x33f [ 56.282643][ T7325] irq_exit+0xbb/0xe0 [ 56.286611][ T7325] do_IRQ+0xdf/0x150 [ 56.290489][ T7325] ret_from_intr+0x0/0x19 [ 56.294828][ T7325] native_safe_halt+0xe/0x10 [ 56.299412][ T7325] [ 56.301729][ T7325] write to 0xffff88812fffcf58 of 8 bytes by task 7325 on cpu 1: [ 56.309342][ T7325] free_one_page+0x214/0x840 [ 56.313917][ T7325] __free_pages_ok+0x370/0x640 [ 56.318667][ T7325] free_compound_page+0x3d/0x50 [ 56.323499][ T7325] __put_compound_page+0x4e/0x70 [ 56.328503][ T7325] __put_page+0x54/0xd0 [ 56.332774][ T7325] skb_release_data+0x1ba/0x3a0 [ 56.337611][ T7325] skb_release_all+0x44/0x60 [ 56.342198][ T7325] __kfree_skb+0x1f/0x30 [ 56.346824][ T7325] tcp_recvmsg+0xf59/0x1a30 [ 56.351411][ T7325] inet_recvmsg+0xbb/0x250 [ 56.355838][ T7325] sock_recvmsg+0x92/0xb0 [ 56.360285][ T7325] sock_read_iter+0x15f/0x1e0 [ 56.364956][ T7325] new_sync_read+0x389/0x4f0 [ 56.369528][ T7325] [ 56.371851][ T7325] Reported by Kernel Concurrency Sanitizer on: [ 56.377992][ T7325] CPU: 1 PID: 7325 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 56.385079][ T7325] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 56.395117][ T7325] ================================================================== [ 56.403160][ T7325] Kernel panic - not syncing: panic_on_warn set ... [ 56.409742][ T7325] CPU: 1 PID: 7325 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 56.416827][ T7325] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 56.426872][ T7325] Call Trace: [ 56.430153][ T7325] dump_stack+0xf5/0x159 [ 56.434397][ T7325] panic+0x209/0x639 [ 56.438298][ T7325] ? tcp_recvmsg+0xf59/0x1a30 [ 56.442960][ T7325] ? vprintk_func+0x8d/0x140 [ 56.447541][ T7325] kcsan_report.cold+0xc/0x1b [ 56.452209][ T7325] __kcsan_setup_watchpoint+0x3ee/0x510 [ 56.457744][ T7325] __tsan_write8+0x32/0x40 [ 56.462156][ T7325] free_one_page+0x214/0x840 [ 56.466742][ T7325] __free_pages_ok+0x370/0x640 [ 56.471514][ T7325] free_compound_page+0x3d/0x50 [ 56.476365][ T7325] __put_compound_page+0x4e/0x70 [ 56.481289][ T7325] __put_page+0x54/0xd0 [ 56.485449][ T7325] skb_release_data+0x1ba/0x3a0 [ 56.490300][ T7325] skb_release_all+0x44/0x60 [ 56.494888][ T7325] __kfree_skb+0x1f/0x30 [ 56.499123][ T7325] tcp_recvmsg+0xf59/0x1a30 [ 56.503627][ T7325] inet_recvmsg+0xbb/0x250 [ 56.508029][ T7325] ? __tsan_read8+0x2c/0x30 [ 56.512520][ T7325] ? inet_sendpage+0x100/0x100 [ 56.517267][ T7325] sock_recvmsg+0x92/0xb0 [ 56.521581][ T7325] sock_read_iter+0x15f/0x1e0 [ 56.526275][ T7325] new_sync_read+0x389/0x4f0 [ 56.530883][ T7325] __vfs_read+0xb1/0xc0 [ 56.535044][ T7325] vfs_read+0x143/0x2c0 [ 56.539188][ T7325] ksys_read+0xd5/0x1b0 [ 56.543334][ T7325] __x64_sys_read+0x4c/0x60 [ 56.547840][ T7325] do_syscall_64+0xcf/0x2f0 [ 56.552335][ T7325] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 56.558342][ T7325] RIP: 0033:0x47c530 [ 56.562251][ T7325] 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 [ 56.581857][ T7325] RSP: 002b:000000c42030f7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 56.590255][ T7325] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 56.598252][ T7325] RDX: 0000000000001000 RSI: 000000c4200c6000 RDI: 0000000000000003 [ 56.606315][ T7325] RBP: 000000c42030f830 R08: 0000000000000000 R09: 0000000000000000 [ 56.614341][ T7325] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000040 [ 56.622339][ T7325] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 57.759425][ T7325] Shutting down cpus with NMI [ 57.765505][ T7325] Kernel Offset: disabled [ 57.769910][ T7325] Rebooting in 86400 seconds..