[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 41.211500][ T26] audit: type=1800 audit(1570884809.648:25): pid=7144 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 41.231602][ T26] audit: type=1800 audit(1570884809.648:26): pid=7144 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 41.251834][ T26] audit: type=1800 audit(1570884809.648:27): pid=7144 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 '10.128.0.94' (ECDSA) to the list of known hosts. 2019/10/12 12:53:42 fuzzer started 2019/10/12 12:53:43 dialing manager at 10.128.0.105:43913 2019/10/12 12:53:43 syscalls: 2523 2019/10/12 12:53:43 code coverage: enabled 2019/10/12 12:53:43 comparison tracing: enabled 2019/10/12 12:53:43 extra coverage: extra coverage is not supported by the kernel 2019/10/12 12:53:43 setuid sandbox: enabled 2019/10/12 12:53:43 namespace sandbox: enabled 2019/10/12 12:53:43 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/12 12:53:43 fault injection: enabled 2019/10/12 12:53:43 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/12 12:53:43 net packet injection: enabled 2019/10/12 12:53:43 net device setup: enabled 2019/10/12 12:53:43 concurrency sanitizer: enabled syzkaller login: [ 55.301777][ T7299] ================================================================== [ 55.309933][ T7299] BUG: KCSAN: data-race in __zone_watermark_ok / free_one_page [ 55.317458][ T7299] [ 55.319774][ T7299] read to 0xffff88812fffcf58 of 8 bytes by interrupt on cpu 0: [ 55.327323][ T7299] __zone_watermark_ok+0x106/0x240 [ 55.332424][ T7299] get_page_from_freelist+0x629/0x2300 [ 55.337867][ T7299] __alloc_pages_nodemask+0x255/0x4d0 [ 55.343221][ T7299] alloc_pages_current+0xd1/0x170 [ 55.348252][ T7299] skb_page_frag_refill+0x16f/0x260 [ 55.353435][ T7299] try_fill_recv+0x51f/0xdc0 [ 55.358010][ T7299] virtnet_poll+0x64c/0x7d0 [ 55.362498][ T7299] net_rx_action+0x3ae/0xa50 [ 55.367072][ T7299] __do_softirq+0x115/0x33f [ 55.371561][ T7299] run_ksoftirqd+0x46/0x60 [ 55.375980][ T7299] smpboot_thread_fn+0x37d/0x4a0 [ 55.380899][ T7299] kthread+0x1d4/0x200 [ 55.384949][ T7299] ret_from_fork+0x1f/0x30 [ 55.389340][ T7299] [ 55.391658][ T7299] write to 0xffff88812fffcf58 of 8 bytes by task 7299 on cpu 1: [ 55.399272][ T7299] free_one_page+0x214/0x840 [ 55.403847][ T7299] __free_pages_ok+0x370/0x640 [ 55.408620][ T7299] free_compound_page+0x3d/0x50 [ 55.413464][ T7299] __put_compound_page+0x4e/0x70 [ 55.418385][ T7299] __put_page+0x54/0xd0 [ 55.422530][ T7299] skb_release_data+0x1ba/0x3a0 [ 55.427361][ T7299] skb_release_all+0x44/0x60 [ 55.431931][ T7299] __kfree_skb+0x1f/0x30 [ 55.436160][ T7299] tcp_recvmsg+0xf59/0x1a30 [ 55.440650][ T7299] inet_recvmsg+0xbb/0x250 [ 55.445048][ T7299] sock_recvmsg+0x92/0xb0 [ 55.449363][ T7299] sock_read_iter+0x15f/0x1e0 [ 55.454041][ T7299] new_sync_read+0x389/0x4f0 [ 55.458608][ T7299] [ 55.460916][ T7299] Reported by Kernel Concurrency Sanitizer on: [ 55.467058][ T7299] CPU: 1 PID: 7299 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 55.474148][ T7299] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 55.484186][ T7299] ================================================================== [ 55.492241][ T7299] Kernel panic - not syncing: panic_on_warn set ... [ 55.498814][ T7299] CPU: 1 PID: 7299 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 55.505900][ T7299] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 55.515934][ T7299] Call Trace: [ 55.519215][ T7299] dump_stack+0xf5/0x159 [ 55.523449][ T7299] panic+0x209/0x639 [ 55.527329][ T7299] ? tcp_recvmsg+0xf59/0x1a30 [ 55.532079][ T7299] ? vprintk_func+0x8d/0x140 [ 55.536657][ T7299] kcsan_report.cold+0xc/0x1b [ 55.541321][ T7299] __kcsan_setup_watchpoint+0x3ee/0x510 [ 55.546855][ T7299] __tsan_write8+0x32/0x40 [ 55.551258][ T7299] free_one_page+0x214/0x840 [ 55.555841][ T7299] __free_pages_ok+0x370/0x640 [ 55.560603][ T7299] free_compound_page+0x3d/0x50 [ 55.565438][ T7299] __put_compound_page+0x4e/0x70 [ 55.570375][ T7299] __put_page+0x54/0xd0 [ 55.574517][ T7299] skb_release_data+0x1ba/0x3a0 [ 55.579355][ T7299] skb_release_all+0x44/0x60 [ 55.583944][ T7299] __kfree_skb+0x1f/0x30 [ 55.588172][ T7299] tcp_recvmsg+0xf59/0x1a30 [ 55.592675][ T7299] inet_recvmsg+0xbb/0x250 [ 55.597076][ T7299] ? __tsan_read8+0x2c/0x30 [ 55.601568][ T7299] ? inet_sendpage+0x100/0x100 [ 55.606315][ T7299] sock_recvmsg+0x92/0xb0 [ 55.610632][ T7299] sock_read_iter+0x15f/0x1e0 [ 55.615304][ T7299] new_sync_read+0x389/0x4f0 [ 55.619894][ T7299] __vfs_read+0xb1/0xc0 [ 55.624040][ T7299] vfs_read+0x143/0x2c0 [ 55.628184][ T7299] ksys_read+0xd5/0x1b0 [ 55.632341][ T7299] __x64_sys_read+0x4c/0x60 [ 55.636833][ T7299] do_syscall_64+0xcf/0x2f0 [ 55.641342][ T7299] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 55.647229][ T7299] RIP: 0033:0x47c530 [ 55.651117][ T7299] 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 [ 55.670825][ T7299] RSP: 002b:000000c4203377d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 55.679225][ T7299] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 55.687178][ T7299] RDX: 0000000000001000 RSI: 000000c4200a6000 RDI: 0000000000000003 [ 55.695144][ T7299] RBP: 000000c420337830 R08: 0000000000000000 R09: 0000000000000000 [ 55.703105][ T7299] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000008 [ 55.711081][ T7299] R13: 000000c420096e00 R14: 0000000000000002 R15: ffffffffffffffff [ 56.847037][ T7299] Shutting down cpus with NMI [ 56.853266][ T7299] Kernel Offset: disabled [ 56.857599][ T7299] Rebooting in 86400 seconds..