[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.699955][ T25] audit: type=1800 audit(1571163960.874:25): pid=7062 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.736288][ T25] audit: type=1800 audit(1571163960.874:26): pid=7062 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.769070][ T25] audit: type=1800 audit(1571163960.874:27): pid=7062 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 '10.128.0.74' (ECDSA) to the list of known hosts. 2019/10/15 18:26:11 fuzzer started 2019/10/15 18:26:12 dialing manager at 10.128.0.105:38903 2019/10/15 18:26:12 syscalls: 2523 2019/10/15 18:26:12 code coverage: enabled 2019/10/15 18:26:12 comparison tracing: enabled 2019/10/15 18:26:12 extra coverage: extra coverage is not supported by the kernel 2019/10/15 18:26:12 setuid sandbox: enabled 2019/10/15 18:26:12 namespace sandbox: enabled 2019/10/15 18:26:12 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/15 18:26:12 fault injection: enabled 2019/10/15 18:26:12 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/15 18:26:12 net packet injection: enabled 2019/10/15 18:26:12 net device setup: enabled 2019/10/15 18:26:12 concurrency sanitizer: enabled syzkaller login: [ 48.422947][ T7217] ================================================================== [ 48.431079][ T7217] BUG: KCSAN: data-race in __zone_watermark_ok / free_one_page [ 48.438596][ T7217] [ 48.440919][ T7217] read to 0xffff88812fffcf58 of 8 bytes by interrupt on cpu 1: [ 48.448459][ T7217] __zone_watermark_ok+0x106/0x240 [ 48.453558][ T7217] get_page_from_freelist+0x629/0x2300 [ 48.459010][ T7217] __alloc_pages_nodemask+0x255/0x4d0 [ 48.464364][ T7217] alloc_pages_current+0xd1/0x170 [ 48.469377][ T7217] skb_page_frag_refill+0x16f/0x260 [ 48.474560][ T7217] try_fill_recv+0x51f/0xdc0 [ 48.479141][ T7217] virtnet_poll+0x64c/0x7d0 [ 48.483625][ T7217] net_rx_action+0x3ae/0xa50 [ 48.488211][ T7217] __do_softirq+0x115/0x33f [ 48.492804][ T7217] irq_exit+0xbb/0xe0 [ 48.496770][ T7217] do_IRQ+0xdf/0x150 [ 48.500646][ T7217] ret_from_intr+0x0/0x19 [ 48.504958][ T7217] __kcsan_check_watchpoint+0x15/0x180 [ 48.510401][ T7217] smpboot_thread_fn+0x13c/0x4a0 [ 48.515583][ T7217] [ 48.517898][ T7217] write to 0xffff88812fffcf58 of 8 bytes by task 7217 on cpu 0: [ 48.525518][ T7217] free_one_page+0x214/0x840 [ 48.530089][ T7217] __free_pages_ok+0x370/0x640 [ 48.534837][ T7217] free_compound_page+0x3d/0x50 [ 48.539671][ T7217] __put_compound_page+0x4e/0x70 [ 48.544617][ T7217] __put_page+0x54/0xd0 [ 48.548766][ T7217] skb_release_data+0x1ba/0x3a0 [ 48.553600][ T7217] skb_release_all+0x44/0x60 [ 48.558266][ T7217] __kfree_skb+0x1f/0x30 [ 48.562491][ T7217] tcp_recvmsg+0xf59/0x1a30 [ 48.566978][ T7217] inet_recvmsg+0xbb/0x250 [ 48.571636][ T7217] sock_recvmsg+0x92/0xb0 [ 48.575947][ T7217] sock_read_iter+0x15f/0x1e0 [ 48.580609][ T7217] new_sync_read+0x389/0x4f0 [ 48.585172][ T7217] [ 48.587479][ T7217] Reported by Kernel Concurrency Sanitizer on: [ 48.593625][ T7217] CPU: 0 PID: 7217 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 48.600712][ T7217] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.610749][ T7217] ================================================================== [ 48.618789][ T7217] Kernel panic - not syncing: panic_on_warn set ... [ 48.625636][ T7217] CPU: 0 PID: 7217 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 48.632728][ T7217] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.642760][ T7217] Call Trace: [ 48.646039][ T7217] dump_stack+0xf5/0x159 [ 48.650267][ T7217] panic+0x209/0x639 [ 48.654148][ T7217] ? tcp_recvmsg+0xf59/0x1a30 [ 48.658817][ T7217] ? vprintk_func+0x8d/0x140 [ 48.663743][ T7217] kcsan_report.cold+0xc/0x1b [ 48.668408][ T7217] __kcsan_setup_watchpoint+0x3ee/0x510 [ 48.673936][ T7217] __tsan_write8+0x32/0x40 [ 48.678340][ T7217] free_one_page+0x214/0x840 [ 48.682929][ T7217] __free_pages_ok+0x370/0x640 [ 48.687680][ T7217] free_compound_page+0x3d/0x50 [ 48.692518][ T7217] __put_compound_page+0x4e/0x70 [ 48.697454][ T7217] __put_page+0x54/0xd0 [ 48.701605][ T7217] skb_release_data+0x1ba/0x3a0 [ 48.706449][ T7217] skb_release_all+0x44/0x60 [ 48.711029][ T7217] __kfree_skb+0x1f/0x30 [ 48.717524][ T7217] tcp_recvmsg+0xf59/0x1a30 [ 48.722037][ T7217] inet_recvmsg+0xbb/0x250 [ 48.726442][ T7217] ? __tsan_read8+0x2c/0x30 [ 48.730932][ T7217] ? inet_sendpage+0x100/0x100 [ 48.735684][ T7217] sock_recvmsg+0x92/0xb0 [ 48.740003][ T7217] sock_read_iter+0x15f/0x1e0 [ 48.744673][ T7217] new_sync_read+0x389/0x4f0 [ 48.749259][ T7217] __vfs_read+0xb1/0xc0 [ 48.753442][ T7217] vfs_read+0x143/0x2c0 [ 48.757588][ T7217] ksys_read+0xd5/0x1b0 [ 48.761742][ T7217] __x64_sys_read+0x4c/0x60 [ 48.766234][ T7217] do_syscall_64+0xcf/0x2f0 [ 48.770725][ T7217] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.776601][ T7217] RIP: 0033:0x47c530 [ 48.780585][ T7217] 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 [ 48.800256][ T7217] RSP: 002b:000000c4204df810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 48.808657][ T7217] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 48.816615][ T7217] RDX: 0000000000001000 RSI: 000000c4200ac000 RDI: 0000000000000003 [ 48.824568][ T7217] RBP: 000000c4204df868 R08: 0000000000000000 R09: 0000000000000000 [ 48.832539][ T7217] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002 [ 48.840671][ T7217] R13: ffffffffffffffff R14: 0000000000000004 R15: ffffffffffffffff [ 49.973388][ T7217] Shutting down cpus with NMI [ 49.979580][ T7217] Kernel Offset: disabled [ 49.983932][ T7217] Rebooting in 86400 seconds..