[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 42.864403][ T26] audit: type=1800 audit(1571008185.182:25): pid=7243 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 42.884250][ T26] audit: type=1800 audit(1571008185.182:26): pid=7243 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 42.905112][ T26] audit: type=1800 audit(1571008185.182:27): pid=7243 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 '10.128.0.20' (ECDSA) to the list of known hosts. 2019/10/13 23:09:56 fuzzer started 2019/10/13 23:09:57 dialing manager at 10.128.0.105:40973 2019/10/13 23:09:57 syscalls: 2523 2019/10/13 23:09:57 code coverage: enabled 2019/10/13 23:09:57 comparison tracing: enabled 2019/10/13 23:09:57 extra coverage: extra coverage is not supported by the kernel 2019/10/13 23:09:57 setuid sandbox: enabled 2019/10/13 23:09:57 namespace sandbox: enabled 2019/10/13 23:09:57 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/13 23:09:57 fault injection: enabled 2019/10/13 23:09:57 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/13 23:09:57 net packet injection: enabled 2019/10/13 23:09:57 net device setup: enabled 2019/10/13 23:09:57 concurrency sanitizer: enabled syzkaller login: [ 55.514703][ T7410] ================================================================== [ 55.522835][ T7410] BUG: KCSAN: data-race in __zone_watermark_ok / free_one_page [ 55.530356][ T7410] [ 55.532681][ T7410] read to 0xffff88812fffcf58 of 8 bytes by interrupt on cpu 0: [ 55.540210][ T7410] __zone_watermark_ok+0x106/0x240 [ 55.545318][ T7410] get_page_from_freelist+0x629/0x2300 [ 55.550762][ T7410] __alloc_pages_nodemask+0x255/0x4d0 [ 55.556118][ T7410] alloc_pages_current+0xd1/0x170 [ 55.561131][ T7410] skb_page_frag_refill+0x16f/0x260 [ 55.566314][ T7410] try_fill_recv+0x51f/0xdc0 [ 55.570891][ T7410] virtnet_poll+0x64c/0x7d0 [ 55.575377][ T7410] net_rx_action+0x3ae/0xa50 [ 55.579949][ T7410] __do_softirq+0x115/0x33f [ 55.584440][ T7410] run_ksoftirqd+0x46/0x60 [ 55.588842][ T7410] smpboot_thread_fn+0x37d/0x4a0 [ 55.593760][ T7410] kthread+0x1d4/0x200 [ 55.597813][ T7410] ret_from_fork+0x1f/0x30 [ 55.602204][ T7410] [ 55.604522][ T7410] write to 0xffff88812fffcf58 of 8 bytes by task 7410 on cpu 1: [ 55.612134][ T7410] free_one_page+0x214/0x840 [ 55.616723][ T7410] __free_pages_ok+0x370/0x640 [ 55.621472][ T7410] free_compound_page+0x3d/0x50 [ 55.626306][ T7410] __put_compound_page+0x4e/0x70 [ 55.631227][ T7410] __put_page+0x54/0xd0 [ 55.635383][ T7410] skb_release_data+0x1ba/0x3a0 [ 55.640219][ T7410] skb_release_all+0x44/0x60 [ 55.644795][ T7410] __kfree_skb+0x1f/0x30 [ 55.649045][ T7410] tcp_recvmsg+0xf59/0x1a30 [ 55.653535][ T7410] inet_recvmsg+0xbb/0x250 [ 55.657943][ T7410] sock_recvmsg+0x92/0xb0 [ 55.662271][ T7410] sock_read_iter+0x15f/0x1e0 [ 55.666953][ T7410] new_sync_read+0x389/0x4f0 [ 55.671519][ T7410] [ 55.673828][ T7410] Reported by Kernel Concurrency Sanitizer on: [ 55.680053][ T7410] CPU: 1 PID: 7410 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 55.687141][ T7410] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 55.697175][ T7410] ================================================================== [ 55.705234][ T7410] Kernel panic - not syncing: panic_on_warn set ... [ 55.711805][ T7410] CPU: 1 PID: 7410 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 55.718895][ T7410] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 55.728930][ T7410] Call Trace: [ 55.732214][ T7410] dump_stack+0xf5/0x159 [ 55.736449][ T7410] panic+0x209/0x639 [ 55.740345][ T7410] ? tcp_recvmsg+0xf59/0x1a30 [ 55.745005][ T7410] ? vprintk_func+0x8d/0x140 [ 55.749583][ T7410] kcsan_report.cold+0xc/0x1b [ 55.754251][ T7410] __kcsan_setup_watchpoint+0x3ee/0x510 [ 55.759798][ T7410] __tsan_write8+0x32/0x40 [ 55.764204][ T7410] free_one_page+0x214/0x840 [ 55.768787][ T7410] __free_pages_ok+0x370/0x640 [ 55.773551][ T7410] free_compound_page+0x3d/0x50 [ 55.778386][ T7410] __put_compound_page+0x4e/0x70 [ 55.783306][ T7410] __put_page+0x54/0xd0 [ 55.787452][ T7410] skb_release_data+0x1ba/0x3a0 [ 55.792296][ T7410] skb_release_all+0x44/0x60 [ 55.796874][ T7410] __kfree_skb+0x1f/0x30 [ 55.801119][ T7410] tcp_recvmsg+0xf59/0x1a30 [ 55.805619][ T7410] ? preempt_schedule_common+0x37/0x90 [ 55.811094][ T7410] inet_recvmsg+0xbb/0x250 [ 55.815708][ T7410] ? __tsan_read8+0x2c/0x30 [ 55.820207][ T7410] ? inet_sendpage+0x100/0x100 [ 55.824967][ T7410] sock_recvmsg+0x92/0xb0 [ 55.829364][ T7410] sock_read_iter+0x15f/0x1e0 [ 55.834040][ T7410] new_sync_read+0x389/0x4f0 [ 55.838639][ T7410] __vfs_read+0xb1/0xc0 [ 55.842784][ T7410] vfs_read+0x143/0x2c0 [ 55.846937][ T7410] ksys_read+0xd5/0x1b0 [ 55.851085][ T7410] __x64_sys_read+0x4c/0x60 [ 55.855578][ T7410] do_syscall_64+0xcf/0x2f0 [ 55.860075][ T7410] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 55.865951][ T7410] RIP: 0033:0x47c530 [ 55.869941][ T7410] 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 [ 55.889797][ T7410] RSP: 002b:000000c42033b7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 55.898287][ T7410] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 55.906250][ T7410] RDX: 0000000000001000 RSI: 000000c420064000 RDI: 0000000000000003 [ 55.914203][ T7410] RBP: 000000c42033b830 R08: 0000000000000000 R09: 0000000000000000 [ 55.922173][ T7410] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000008 [ 55.930128][ T7410] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 57.066962][ T7410] Shutting down cpus with NMI [ 57.073640][ T7410] Kernel Offset: disabled [ 57.077997][ T7410] Rebooting in 86400 seconds..