[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.773752][ T26] audit: type=1800 audit(1570968542.890:25): pid=7096 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.811070][ T26] audit: type=1800 audit(1570968542.900:26): pid=7096 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.831873][ T26] audit: type=1800 audit(1570968542.900:27): pid=7096 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 '10.128.0.134' (ECDSA) to the list of known hosts. 2019/10/13 12:09:11 fuzzer started 2019/10/13 12:09:13 dialing manager at 10.128.0.105:40973 2019/10/13 12:09:13 syscalls: 2523 2019/10/13 12:09:13 code coverage: enabled 2019/10/13 12:09:13 comparison tracing: enabled 2019/10/13 12:09:13 extra coverage: extra coverage is not supported by the kernel 2019/10/13 12:09:13 setuid sandbox: enabled 2019/10/13 12:09:13 namespace sandbox: enabled 2019/10/13 12:09:13 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/13 12:09:13 fault injection: enabled 2019/10/13 12:09:13 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/13 12:09:13 net packet injection: enabled 2019/10/13 12:09:13 net device setup: enabled 2019/10/13 12:09:13 concurrency sanitizer: enabled syzkaller login: [ 47.062919][ T7254] ================================================================== [ 47.071054][ T7254] BUG: KCSAN: data-race in __zone_watermark_ok / free_one_page [ 47.078569][ T7254] [ 47.080886][ T7254] read to 0xffff88812fffcf58 of 8 bytes by interrupt on cpu 1: [ 47.088413][ T7254] __zone_watermark_ok+0x106/0x240 [ 47.093508][ T7254] get_page_from_freelist+0x629/0x2300 [ 47.098953][ T7254] __alloc_pages_nodemask+0x255/0x4d0 [ 47.104324][ T7254] alloc_pages_current+0xd1/0x170 [ 47.109338][ T7254] skb_page_frag_refill+0x16f/0x260 [ 47.114520][ T7254] try_fill_recv+0x51f/0xdc0 [ 47.119095][ T7254] virtnet_poll+0x64c/0x7d0 [ 47.123582][ T7254] net_rx_action+0x3ae/0xa50 [ 47.128155][ T7254] __do_softirq+0x115/0x33f [ 47.132641][ T7254] run_ksoftirqd+0x46/0x60 [ 47.137055][ T7254] smpboot_thread_fn+0x37d/0x4a0 [ 47.141978][ T7254] kthread+0x1d4/0x200 [ 47.146066][ T7254] ret_from_fork+0x1f/0x30 [ 47.150465][ T7254] [ 47.152782][ T7254] write to 0xffff88812fffcf58 of 8 bytes by task 7254 on cpu 0: [ 47.160403][ T7254] free_one_page+0x214/0x840 [ 47.164974][ T7254] __free_pages_ok+0x370/0x640 [ 47.169719][ T7254] page_frag_free+0xd0/0x100 [ 47.174289][ T7254] skb_free_head+0x55/0x80 [ 47.178698][ T7254] skb_release_data+0x25d/0x3a0 [ 47.183528][ T7254] skb_release_all+0x44/0x60 [ 47.188096][ T7254] __kfree_skb+0x1f/0x30 [ 47.192322][ T7254] tcp_recvmsg+0xf59/0x1a30 [ 47.196810][ T7254] inet_recvmsg+0xbb/0x250 [ 47.201222][ T7254] sock_recvmsg+0x92/0xb0 [ 47.205529][ T7254] sock_read_iter+0x15f/0x1e0 [ 47.210190][ T7254] new_sync_read+0x389/0x4f0 [ 47.214761][ T7254] __vfs_read+0xb1/0xc0 [ 47.218891][ T7254] [ 47.221216][ T7254] Reported by Kernel Concurrency Sanitizer on: [ 47.227361][ T7254] CPU: 0 PID: 7254 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.234450][ T7254] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.244487][ T7254] ================================================================== [ 47.252531][ T7254] Kernel panic - not syncing: panic_on_warn set ... [ 47.259124][ T7254] CPU: 0 PID: 7254 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.266214][ T7254] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.276249][ T7254] Call Trace: [ 47.279537][ T7254] dump_stack+0xf5/0x159 [ 47.283770][ T7254] panic+0x209/0x639 [ 47.287654][ T7254] ? inet_recvmsg+0xbb/0x250 [ 47.292228][ T7254] ? vprintk_func+0x8d/0x140 [ 47.296811][ T7254] kcsan_report.cold+0xc/0x1b [ 47.301477][ T7254] __kcsan_setup_watchpoint+0x3ee/0x510 [ 47.307018][ T7254] __tsan_write8+0x32/0x40 [ 47.311430][ T7254] free_one_page+0x214/0x840 [ 47.316013][ T7254] __free_pages_ok+0x370/0x640 [ 47.320768][ T7254] page_frag_free+0xd0/0x100 [ 47.325341][ T7254] skb_free_head+0x55/0x80 [ 47.329742][ T7254] skb_release_data+0x25d/0x3a0 [ 47.334580][ T7254] skb_release_all+0x44/0x60 [ 47.339151][ T7254] __kfree_skb+0x1f/0x30 [ 47.343376][ T7254] tcp_recvmsg+0xf59/0x1a30 [ 47.347875][ T7254] inet_recvmsg+0xbb/0x250 [ 47.352278][ T7254] ? __tsan_read8+0x2c/0x30 [ 47.356769][ T7254] ? inet_sendpage+0x100/0x100 [ 47.361519][ T7254] sock_recvmsg+0x92/0xb0 [ 47.365833][ T7254] sock_read_iter+0x15f/0x1e0 [ 47.370503][ T7254] new_sync_read+0x389/0x4f0 [ 47.375087][ T7254] __vfs_read+0xb1/0xc0 [ 47.379227][ T7254] vfs_read+0x143/0x2c0 [ 47.383369][ T7254] ksys_read+0xd5/0x1b0 [ 47.387513][ T7254] __x64_sys_read+0x4c/0x60 [ 47.392001][ T7254] do_syscall_64+0xcf/0x2f0 [ 47.396495][ T7254] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.402370][ T7254] RIP: 0033:0x47c530 [ 47.406258][ T7254] 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 [ 47.425844][ T7254] RSP: 002b:000000c42036f7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 47.434236][ T7254] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.442187][ T7254] RDX: 0000000000001000 RSI: 000000c42016c000 RDI: 0000000000000003 [ 47.450140][ T7254] RBP: 000000c42036f830 R08: 0000000000000000 R09: 0000000000000000 [ 47.458095][ T7254] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000004 [ 47.466052][ T7254] R13: 000000c4200218a0 R14: 0000000000000002 R15: ffffffffffffffff [ 48.602193][ T7254] Shutting down cpus with NMI [ 48.608294][ T7254] Kernel Offset: disabled [ 48.612614][ T7254] Rebooting in 86400 seconds..