[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 33.712958][ T25] audit: type=1800 audit(1570868675.858:25): pid=6974 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 33.749335][ T25] audit: type=1800 audit(1570868675.858:26): pid=6974 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 33.788657][ T25] audit: type=1800 audit(1570868675.858:27): pid=6974 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 '10.128.1.58' (ECDSA) to the list of known hosts. 2019/10/12 08:24:47 fuzzer started 2019/10/12 08:24:48 dialing manager at 10.128.0.105:43913 2019/10/12 08:24:48 syscalls: 2523 2019/10/12 08:24:48 code coverage: enabled 2019/10/12 08:24:48 comparison tracing: enabled 2019/10/12 08:24:48 extra coverage: extra coverage is not supported by the kernel 2019/10/12 08:24:48 setuid sandbox: enabled 2019/10/12 08:24:48 namespace sandbox: enabled 2019/10/12 08:24:48 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/12 08:24:48 fault injection: enabled 2019/10/12 08:24:48 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/12 08:24:48 net packet injection: enabled 2019/10/12 08:24:48 net device setup: enabled 2019/10/12 08:24:48 concurrency sanitizer: enabled syzkaller login: [ 46.690364][ T7142] ================================================================== [ 46.698496][ T7142] BUG: KCSAN: data-race in __zone_watermark_ok / free_one_page [ 46.706012][ T7142] [ 46.708324][ T7142] read to 0xffff88812fffcf58 of 8 bytes by interrupt on cpu 1: [ 46.715851][ T7142] __zone_watermark_ok+0x106/0x240 [ 46.720944][ T7142] get_page_from_freelist+0x629/0x2300 [ 46.726388][ T7142] __alloc_pages_nodemask+0x255/0x4d0 [ 46.731743][ T7142] page_frag_alloc+0x11e/0x2d0 [ 46.736490][ T7142] __napi_alloc_skb+0x172/0x210 [ 46.741326][ T7142] page_to_skb+0x8d/0x480 [ 46.745646][ T7142] receive_buf+0x17c7/0x30b0 [ 46.750220][ T7142] virtnet_poll+0x436/0x7d0 [ 46.754705][ T7142] net_rx_action+0x3ae/0xa50 [ 46.759276][ T7142] __do_softirq+0x115/0x33f [ 46.763772][ T7142] run_ksoftirqd+0x46/0x60 [ 46.768169][ T7142] smpboot_thread_fn+0x37d/0x4a0 [ 46.773089][ T7142] kthread+0x1d4/0x200 [ 46.777136][ T7142] ret_from_fork+0x1f/0x30 [ 46.781527][ T7142] [ 46.783841][ T7142] write to 0xffff88812fffcf58 of 8 bytes by task 7142 on cpu 0: [ 46.791461][ T7142] free_one_page+0x214/0x840 [ 46.796034][ T7142] __free_pages_ok+0x370/0x640 [ 46.800779][ T7142] free_compound_page+0x3d/0x50 [ 46.805612][ T7142] __put_compound_page+0x4e/0x70 [ 46.810531][ T7142] __put_page+0x54/0xd0 [ 46.814669][ T7142] skb_release_data+0x1ba/0x3a0 [ 46.819499][ T7142] skb_release_all+0x44/0x60 [ 46.824070][ T7142] __kfree_skb+0x1f/0x30 [ 46.828295][ T7142] tcp_recvmsg+0xf59/0x1a30 [ 46.832780][ T7142] inet_recvmsg+0xbb/0x250 [ 46.837184][ T7142] sock_recvmsg+0x92/0xb0 [ 46.841496][ T7142] sock_read_iter+0x15f/0x1e0 [ 46.846155][ T7142] new_sync_read+0x389/0x4f0 [ 46.850717][ T7142] [ 46.853024][ T7142] Reported by Kernel Concurrency Sanitizer on: [ 46.859160][ T7142] CPU: 0 PID: 7142 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 46.866243][ T7142] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.876276][ T7142] ================================================================== [ 46.884313][ T7142] Kernel panic - not syncing: panic_on_warn set ... [ 46.890890][ T7142] CPU: 0 PID: 7142 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 46.897973][ T7142] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.908012][ T7142] Call Trace: [ 46.911295][ T7142] dump_stack+0xf5/0x159 [ 46.915529][ T7142] panic+0x209/0x639 [ 46.919409][ T7142] ? tcp_recvmsg+0xf59/0x1a30 [ 46.924069][ T7142] ? vprintk_func+0x8d/0x140 [ 46.928647][ T7142] kcsan_report.cold+0xc/0x1b [ 46.933307][ T7142] __kcsan_setup_watchpoint+0x3ee/0x510 [ 46.938849][ T7142] __tsan_write8+0x32/0x40 [ 46.943254][ T7142] free_one_page+0x214/0x840 [ 46.947837][ T7142] __free_pages_ok+0x370/0x640 [ 46.952591][ T7142] free_compound_page+0x3d/0x50 [ 46.957426][ T7142] __put_compound_page+0x4e/0x70 [ 46.962344][ T7142] __put_page+0x54/0xd0 [ 46.966483][ T7142] skb_release_data+0x1ba/0x3a0 [ 46.971332][ T7142] skb_release_all+0x44/0x60 [ 46.975904][ T7142] __kfree_skb+0x1f/0x30 [ 46.980137][ T7142] tcp_recvmsg+0xf59/0x1a30 [ 46.984642][ T7142] inet_recvmsg+0xbb/0x250 [ 46.989043][ T7142] ? __tsan_read8+0x2c/0x30 [ 46.993542][ T7142] ? inet_sendpage+0x100/0x100 [ 46.998287][ T7142] sock_recvmsg+0x92/0xb0 [ 47.002603][ T7142] sock_read_iter+0x15f/0x1e0 [ 47.007277][ T7142] new_sync_read+0x389/0x4f0 [ 47.011861][ T7142] __vfs_read+0xb1/0xc0 [ 47.016002][ T7142] vfs_read+0x143/0x2c0 [ 47.020148][ T7142] ksys_read+0xd5/0x1b0 [ 47.024294][ T7142] __x64_sys_read+0x4c/0x60 [ 47.028795][ T7142] do_syscall_64+0xcf/0x2f0 [ 47.033311][ T7142] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.039186][ T7142] RIP: 0033:0x47c530 [ 47.043078][ T7142] 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 [ 47.062687][ T7142] RSP: 002b:000000c4202c37d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 47.071088][ T7142] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.079039][ T7142] RDX: 0000000000001000 RSI: 000000c42014c000 RDI: 0000000000000003 [ 47.087003][ T7142] RBP: 000000c4202c3830 R08: 0000000000000000 R09: 0000000000000000 [ 47.094963][ T7142] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000004 [ 47.102916][ T7142] R13: 000000c4200217c0 R14: 0000000000000002 R15: ffffffffffffffff [ 48.240080][ T7142] Shutting down cpus with NMI [ 48.246010][ T7142] Kernel Offset: disabled [ 48.250344][ T7142] Rebooting in 86400 seconds..