[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.039876][ T26] audit: type=1800 audit(1571027679.525:25): pid=7091 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.078819][ T26] audit: type=1800 audit(1571027679.525:26): pid=7091 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.108856][ T26] audit: type=1800 audit(1571027679.525:27): pid=7091 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 '10.128.0.41' (ECDSA) to the list of known hosts. 2019/10/14 04:34:50 fuzzer started 2019/10/14 04:34:50 dialing manager at 10.128.0.105:40973 2019/10/14 04:34:50 syscalls: 2523 2019/10/14 04:34:50 code coverage: enabled 2019/10/14 04:34:50 comparison tracing: enabled 2019/10/14 04:34:50 extra coverage: extra coverage is not supported by the kernel 2019/10/14 04:34:50 setuid sandbox: enabled 2019/10/14 04:34:50 namespace sandbox: enabled 2019/10/14 04:34:50 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/14 04:34:50 fault injection: enabled 2019/10/14 04:34:50 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/14 04:34:50 net packet injection: enabled 2019/10/14 04:34:50 net device setup: enabled 2019/10/14 04:34:50 concurrency sanitizer: enabled syzkaller login: [ 46.839138][ T7257] ================================================================== [ 46.847284][ T7257] BUG: KCSAN: data-race in __zone_watermark_ok / free_one_page [ 46.854805][ T7257] [ 46.857467][ T7257] read to 0xffff88812fffcf58 of 8 bytes by interrupt on cpu 1: [ 46.865125][ T7257] __zone_watermark_ok+0x106/0x240 [ 46.870224][ T7257] get_page_from_freelist+0x629/0x2300 [ 46.875682][ T7257] __alloc_pages_nodemask+0x255/0x4d0 [ 46.881063][ T7257] alloc_pages_current+0xd1/0x170 [ 46.886112][ T7257] skb_page_frag_refill+0x16f/0x260 [ 46.891298][ T7257] try_fill_recv+0x51f/0xdc0 [ 46.895872][ T7257] virtnet_poll+0x64c/0x7d0 [ 46.900358][ T7257] net_rx_action+0x3ae/0xa50 [ 46.904934][ T7257] __do_softirq+0x115/0x33f [ 46.909435][ T7257] run_ksoftirqd+0x46/0x60 [ 46.913835][ T7257] smpboot_thread_fn+0x37d/0x4a0 [ 46.918769][ T7257] kthread+0x1d4/0x200 [ 46.922833][ T7257] ret_from_fork+0x1f/0x30 [ 46.927225][ T7257] [ 46.929554][ T7257] write to 0xffff88812fffcf58 of 8 bytes by task 7257 on cpu 0: [ 46.937171][ T7257] free_one_page+0x783/0x840 [ 46.941750][ T7257] __free_pages_ok+0x370/0x640 [ 46.946500][ T7257] free_compound_page+0x3d/0x50 [ 46.951336][ T7257] __put_compound_page+0x4e/0x70 [ 46.956274][ T7257] __put_page+0x54/0xd0 [ 46.960414][ T7257] skb_release_data+0x1ba/0x3a0 [ 46.965245][ T7257] skb_release_all+0x44/0x60 [ 46.969837][ T7257] __kfree_skb+0x1f/0x30 [ 46.974067][ T7257] tcp_recvmsg+0xf59/0x1a30 [ 46.978556][ T7257] inet_recvmsg+0xbb/0x250 [ 46.982970][ T7257] sock_recvmsg+0x92/0xb0 [ 46.987287][ T7257] sock_read_iter+0x15f/0x1e0 [ 46.991950][ T7257] new_sync_read+0x389/0x4f0 [ 46.996603][ T7257] [ 46.998940][ T7257] Reported by Kernel Concurrency Sanitizer on: [ 47.005081][ T7257] CPU: 0 PID: 7257 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.012257][ T7257] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.022295][ T7257] ================================================================== [ 47.030339][ T7257] Kernel panic - not syncing: panic_on_warn set ... [ 47.036912][ T7257] CPU: 0 PID: 7257 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.044001][ T7257] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.054140][ T7257] Call Trace: [ 47.057422][ T7257] dump_stack+0xf5/0x159 [ 47.061654][ T7257] panic+0x209/0x639 [ 47.065537][ T7257] ? tcp_recvmsg+0xf59/0x1a30 [ 47.070200][ T7257] ? vprintk_func+0x8d/0x140 [ 47.074779][ T7257] kcsan_report.cold+0xc/0x1b [ 47.079447][ T7257] __kcsan_setup_watchpoint+0x3ee/0x510 [ 47.084983][ T7257] __tsan_write8+0x32/0x40 [ 47.089389][ T7257] free_one_page+0x783/0x840 [ 47.093973][ T7257] __free_pages_ok+0x370/0x640 [ 47.098730][ T7257] free_compound_page+0x3d/0x50 [ 47.103569][ T7257] __put_compound_page+0x4e/0x70 [ 47.108492][ T7257] __put_page+0x54/0xd0 [ 47.113419][ T7257] skb_release_data+0x1ba/0x3a0 [ 47.118284][ T7257] skb_release_all+0x44/0x60 [ 47.123482][ T7257] __kfree_skb+0x1f/0x30 [ 47.127723][ T7257] tcp_recvmsg+0xf59/0x1a30 [ 47.132675][ T7257] inet_recvmsg+0xbb/0x250 [ 47.137077][ T7257] ? __tsan_read8+0x2c/0x30 [ 47.141567][ T7257] ? inet_sendpage+0x100/0x100 [ 47.146319][ T7257] sock_recvmsg+0x92/0xb0 [ 47.150633][ T7257] sock_read_iter+0x15f/0x1e0 [ 47.155305][ T7257] new_sync_read+0x389/0x4f0 [ 47.159892][ T7257] __vfs_read+0xb1/0xc0 [ 47.164042][ T7257] vfs_read+0x143/0x2c0 [ 47.168190][ T7257] ksys_read+0xd5/0x1b0 [ 47.172352][ T7257] __x64_sys_read+0x4c/0x60 [ 47.176847][ T7257] do_syscall_64+0xcf/0x2f0 [ 47.181355][ T7257] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.187245][ T7257] RIP: 0033:0x47c530 [ 47.191131][ T7257] 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 [ 47.210734][ T7257] RSP: 002b:000000c420341810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 47.219219][ T7257] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.227177][ T7257] RDX: 0000000000001000 RSI: 000000c4202e2000 RDI: 0000000000000003 [ 47.235222][ T7257] RBP: 000000c420341868 R08: 0000000000000000 R09: 0000000000000000 [ 47.243183][ T7257] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 [ 47.251141][ T7257] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 48.387695][ T7257] Shutting down cpus with NMI [ 48.393865][ T7257] Kernel Offset: disabled [ 48.398191][ T7257] Rebooting in 86400 seconds..