[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 36.427310][ T25] audit: type=1800 audit(1570191489.332:25): pid=7093 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 36.447007][ T25] audit: type=1800 audit(1570191489.332:26): pid=7093 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 36.476390][ T25] audit: type=1800 audit(1570191489.342:27): pid=7093 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 '10.128.1.18' (ECDSA) to the list of known hosts. 2019/10/04 12:18:19 fuzzer started 2019/10/04 12:18:21 dialing manager at 10.128.0.105:38119 2019/10/04 12:18:21 syscalls: 2523 2019/10/04 12:18:21 code coverage: enabled 2019/10/04 12:18:21 comparison tracing: enabled 2019/10/04 12:18:21 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:18:21 setuid sandbox: enabled 2019/10/04 12:18:21 namespace sandbox: enabled 2019/10/04 12:18:21 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:18:21 fault injection: enabled 2019/10/04 12:18:21 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:18:21 net packet injection: enabled 2019/10/04 12:18:21 net device setup: enabled 2019/10/04 12:18:21 concurrency sanitizer: enabled syzkaller login: [ 49.424839][ T7246] ================================================================== [ 49.433121][ T7246] BUG: KCSAN: data-race in __zone_watermark_ok+0x106/0x240 and free_one_page+0x214/0x840 [ 49.442892][ T7246] [ 49.445234][ T7246] read to 0xffff88812fffcf58 of 8 bytes by interrupt on cpu 0: [ 49.452762][ T7246] __zone_watermark_ok+0x106/0x240 [ 49.457857][ T7246] get_page_from_freelist+0x629/0x2300 [ 49.463299][ T7246] __alloc_pages_nodemask+0x255/0x4d0 [ 49.468659][ T7246] alloc_pages_current+0xd1/0x170 [ 49.473667][ T7246] skb_page_frag_refill+0x16f/0x260 [ 49.478847][ T7246] try_fill_recv+0x51f/0xdc0 [ 49.483420][ T7246] virtnet_poll+0x64c/0x7d0 [ 49.487903][ T7246] net_rx_action+0x3ae/0xa50 [ 49.492473][ T7246] __do_softirq+0x115/0x33f [ 49.496957][ T7246] run_ksoftirqd+0x46/0x60 [ 49.501356][ T7246] smpboot_thread_fn+0x37d/0x4a0 [ 49.506274][ T7246] kthread+0x1d4/0x200 [ 49.510327][ T7246] ret_from_fork+0x1f/0x30 [ 49.514714][ T7246] [ 49.517030][ T7246] write to 0xffff88812fffcf58 of 8 bytes by task 7246 on cpu 1: [ 49.524647][ T7246] free_one_page+0x214/0x840 [ 49.529222][ T7246] __free_pages_ok+0x370/0x640 [ 49.533968][ T7246] page_frag_free+0xd0/0x100 [ 49.538552][ T7246] skb_free_head+0x55/0x80 [ 49.542952][ T7246] skb_release_data+0x25d/0x3a0 [ 49.547795][ T7246] skb_release_all+0x44/0x60 [ 49.552367][ T7246] __kfree_skb+0x1f/0x30 [ 49.556593][ T7246] tcp_recvmsg+0xf59/0x1a30 [ 49.561091][ T7246] inet_recvmsg+0xbb/0x250 [ 49.565499][ T7246] sock_recvmsg+0x92/0xb0 [ 49.569811][ T7246] sock_read_iter+0x15f/0x1e0 [ 49.574476][ T7246] new_sync_read+0x389/0x4f0 [ 49.579047][ T7246] __vfs_read+0xb1/0xc0 [ 49.583188][ T7246] [ 49.585497][ T7246] Reported by Kernel Concurrency Sanitizer on: [ 49.591818][ T7246] CPU: 1 PID: 7246 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 49.598904][ T7246] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.608938][ T7246] ================================================================== [ 49.616980][ T7246] Kernel panic - not syncing: panic_on_warn set ... [ 49.623554][ T7246] CPU: 1 PID: 7246 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 49.630642][ T7246] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.640675][ T7246] Call Trace: [ 49.643953][ T7246] dump_stack+0xf5/0x159 [ 49.648181][ T7246] panic+0x209/0x639 [ 49.652160][ T7246] ? vprintk_func+0x8d/0x140 [ 49.656739][ T7246] kcsan_report.cold+0x57/0xeb [ 49.661503][ T7246] __kcsan_setup_watchpoint+0x342/0x500 [ 49.667034][ T7246] __tsan_write8+0x32/0x40 [ 49.671438][ T7246] free_one_page+0x214/0x840 [ 49.676019][ T7246] __free_pages_ok+0x370/0x640 [ 49.680772][ T7246] page_frag_free+0xd0/0x100 [ 49.685344][ T7246] skb_free_head+0x55/0x80 [ 49.689746][ T7246] skb_release_data+0x25d/0x3a0 [ 49.694582][ T7246] skb_release_all+0x44/0x60 [ 49.699155][ T7246] __kfree_skb+0x1f/0x30 [ 49.703381][ T7246] tcp_recvmsg+0xf59/0x1a30 [ 49.707878][ T7246] inet_recvmsg+0xbb/0x250 [ 49.712275][ T7246] ? __tsan_read8+0x2c/0x30 [ 49.716765][ T7246] ? inet_sendpage+0x100/0x100 [ 49.721515][ T7246] sock_recvmsg+0x92/0xb0 [ 49.725834][ T7246] sock_read_iter+0x15f/0x1e0 [ 49.730501][ T7246] new_sync_read+0x389/0x4f0 [ 49.735080][ T7246] __vfs_read+0xb1/0xc0 [ 49.739221][ T7246] vfs_read+0x143/0x2c0 [ 49.743362][ T7246] ksys_read+0xd5/0x1b0 [ 49.747517][ T7246] __x64_sys_read+0x4c/0x60 [ 49.752005][ T7246] do_syscall_64+0xcf/0x2f0 [ 49.756497][ T7246] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.762370][ T7246] RIP: 0033:0x47c530 [ 49.766252][ T7246] 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 [ 49.785835][ T7246] RSP: 002b:000000c4202ed7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 49.794229][ T7246] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 49.802184][ T7246] RDX: 0000000000001000 RSI: 000000c4202d2000 RDI: 0000000000000003 [ 49.810139][ T7246] RBP: 000000c4202ed830 R08: 0000000000000000 R09: 0000000000000000 [ 49.818094][ T7246] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000020 [ 49.826066][ T7246] R13: ffffffffffffffff R14: 0000000000000008 R15: ffffffffffffffff [ 50.965138][ T7246] Shutting down cpus with NMI [ 50.971215][ T7246] Kernel Offset: disabled [ 50.975530][ T7246] Rebooting in 86400 seconds..