[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 81.827001][ T31] audit: type=1800 audit(1572373427.887:25): pid=11167 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 81.850542][ T31] audit: type=1800 audit(1572373427.907:26): pid=11167 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 81.887746][ T31] audit: type=1800 audit(1572373427.937:27): pid=11167 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 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 '10.128.1.60' (ECDSA) to the list of known hosts. 2019/10/29 18:24:02 fuzzer started 2019/10/29 18:24:06 dialing manager at 10.128.0.26:45217 2019/10/29 18:24:09 syscalls: 2431 2019/10/29 18:24:09 code coverage: enabled 2019/10/29 18:24:09 comparison tracing: CONFIG_KCOV_ENABLE_COMPARISONS is not enabled 2019/10/29 18:24:09 extra coverage: enabled 2019/10/29 18:24:09 setuid sandbox: enabled 2019/10/29 18:24:09 namespace sandbox: enabled 2019/10/29 18:24:09 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/29 18:24:09 fault injection: enabled 2019/10/29 18:24:09 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/29 18:24:09 net packet injection: enabled 2019/10/29 18:24:09 net device setup: enabled 2019/10/29 18:24:09 concurrency sanitizer: /sys/kernel/debug/kcsan does not exist syzkaller login: [ 144.968657][ C1] ===================================================== [ 144.975705][ C1] BUG: KMSAN: use-after-free in kmem_cache_free+0x3df/0x2b70 [ 144.983335][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc5+ #0 [ 144.990709][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 145.000786][ C1] Call Trace: [ 145.004130][ C1] dump_stack+0x191/0x1f0 [ 145.008493][ C1] kmsan_report+0x128/0x220 [ 145.013050][ C1] __msan_warning+0x73/0xe0 [ 145.017583][ C1] kmem_cache_free+0x3df/0x2b70 [ 145.022460][ C1] ? kmsan_internal_set_origin+0x6a/0xb0 [ 145.028127][ C1] ? kfree_skb+0x473/0x4c0 [ 145.032552][ C1] ? kmsan_internal_unpoison_shadow+0x42/0x80 [ 145.038830][ C1] kfree_skb+0x473/0x4c0 [ 145.043219][ C1] ? packet_rcv_spkt+0x68d/0x7c0 [ 145.048206][ C1] packet_rcv_spkt+0x68d/0x7c0 [ 145.052991][ C1] ? packet_rcv+0x2110/0x2110 [ 145.057658][ C1] __netif_receive_skb_core+0x3aed/0x51a0 [ 145.063380][ C1] ? kmsan_get_shadow_origin_ptr+0x91/0x4b0 [ 145.069274][ C1] netif_receive_skb_internal+0x3cc/0xc20 [ 145.075072][ C1] napi_gro_receive+0x67f/0xbb0 [ 145.079916][ C1] receive_buf+0x653b/0x8810 [ 145.084512][ C1] ? kmsan_get_shadow_origin_ptr+0x91/0x4b0 [ 145.090397][ C1] virtnet_poll+0x666/0x1a10 [ 145.095012][ C1] ? refill_work+0x470/0x470 [ 145.099614][ C1] net_rx_action+0x7a6/0x1aa0 [ 145.104435][ C1] ? net_tx_action+0xc40/0xc40 [ 145.109204][ C1] __do_softirq+0x4a1/0x83a [ 145.113757][ C1] ? ksoftirqd_should_run+0x30/0x30 [ 145.119174][ C1] ? takeover_tasklets+0x900/0x900 [ 145.124292][ C1] run_ksoftirqd+0x25/0x40 [ 145.128721][ C1] smpboot_thread_fn+0x4a3/0x990 [ 145.133666][ C1] kthread+0x4b5/0x4f0 [ 145.137720][ C1] ? cpu_report_death+0x190/0x190 [ 145.142731][ C1] ? kthread_blkcg+0xf0/0xf0 [ 145.147312][ C1] ret_from_fork+0x35/0x40 [ 145.151711][ C1] [ 145.154458][ C1] Uninit was stored to memory at: [ 145.159472][ C1] kmsan_internal_chain_origin+0xbd/0x180 [ 145.165173][ C1] __msan_chain_origin+0x6b/0xd0 [ 145.170092][ C1] ___slab_alloc+0x1dbc/0x1fb0 [ 145.174837][ C1] kmem_cache_alloc+0xadf/0xd20 [ 145.179670][ C1] skb_clone+0x326/0x5d0 [ 145.183892][ C1] packet_rcv_spkt+0x23f/0x7c0 [ 145.188651][ C1] __netif_receive_skb_core+0x3aed/0x51a0 [ 145.194369][ C1] netif_receive_skb_internal+0x3cc/0xc20 [ 145.200095][ C1] napi_gro_receive+0x67f/0xbb0 [ 145.205032][ C1] receive_buf+0x653b/0x8810 [ 145.209609][ C1] virtnet_poll+0x666/0x1a10 [ 145.214178][ C1] net_rx_action+0x7a6/0x1aa0 [ 145.218854][ C1] __do_softirq+0x4a1/0x83a [ 145.223340][ C1] run_ksoftirqd+0x25/0x40 [ 145.227876][ C1] smpboot_thread_fn+0x4a3/0x990 [ 145.232819][ C1] kthread+0x4b5/0x4f0 [ 145.236998][ C1] ret_from_fork+0x35/0x40 [ 145.243913][ C1] [ 145.246229][ C1] Uninit was created at: [ 145.250563][ C1] kmsan_internal_poison_shadow+0x60/0x120 [ 145.256541][ C1] kmsan_slab_free+0x8d/0xf0 [ 145.261130][ C1] kmem_cache_free_bulk+0x3ad9/0x3f10 [ 145.266484][ C1] __kfree_skb_flush+0xb0/0x100 [ 145.271336][ C1] net_rx_action+0x1a5e/0x1aa0 [ 145.276088][ C1] __do_softirq+0x4a1/0x83a [ 145.280572][ C1] irq_exit+0x230/0x280 [ 145.284725][ C1] do_IRQ+0x123/0x360 [ 145.288721][ C1] ret_from_intr+0x0/0x33 [ 145.293037][ C1] default_idle+0x53/0x90 [ 145.297350][ C1] arch_cpu_idle+0x25/0x30 [ 145.301751][ C1] do_idle+0x1d5/0x780 [ 145.305799][ C1] cpu_startup_entry+0x45/0x50 [ 145.310576][ C1] start_secondary+0x389/0x480 [ 145.315330][ C1] secondary_startup_64+0xa4/0xb0 [ 145.320543][ C1] ===================================================== [ 145.327470][ C1] Disabling lock debugging due to kernel taint [ 145.333697][ C1] Kernel panic - not syncing: panic_on_warn set ... [ 145.340267][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Tainted: G B 5.4.0-rc5+ #0 [ 145.349001][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 145.359038][ C1] Call Trace: [ 145.362321][ C1] dump_stack+0x191/0x1f0 [ 145.366634][ C1] panic+0x3c9/0xc1e [ 145.370525][ C1] kmsan_report+0x215/0x220 [ 145.375038][ C1] __msan_warning+0x73/0xe0 [ 145.379525][ C1] kmem_cache_free+0x3df/0x2b70 [ 145.384374][ C1] ? kmsan_internal_set_origin+0x6a/0xb0 [ 145.389990][ C1] ? kfree_skb+0x473/0x4c0 [ 145.394389][ C1] ? kmsan_internal_unpoison_shadow+0x42/0x80 [ 145.400449][ C1] kfree_skb+0x473/0x4c0 [ 145.404702][ C1] ? packet_rcv_spkt+0x68d/0x7c0 [ 145.409625][ C1] packet_rcv_spkt+0x68d/0x7c0 [ 145.414390][ C1] ? packet_rcv+0x2110/0x2110 [ 145.419053][ C1] __netif_receive_skb_core+0x3aed/0x51a0 [ 145.424772][ C1] ? kmsan_get_shadow_origin_ptr+0x91/0x4b0 [ 145.430653][ C1] netif_receive_skb_internal+0x3cc/0xc20 [ 145.436380][ C1] napi_gro_receive+0x67f/0xbb0 [ 145.441233][ C1] receive_buf+0x653b/0x8810 [ 145.445848][ C1] ? kmsan_get_shadow_origin_ptr+0x91/0x4b0 [ 145.451729][ C1] virtnet_poll+0x666/0x1a10 [ 145.456329][ C1] ? refill_work+0x470/0x470 [ 145.460902][ C1] net_rx_action+0x7a6/0x1aa0 [ 145.465571][ C1] ? net_tx_action+0xc40/0xc40 [ 145.470321][ C1] __do_softirq+0x4a1/0x83a [ 145.474816][ C1] ? ksoftirqd_should_run+0x30/0x30 [ 145.480017][ C1] ? takeover_tasklets+0x900/0x900 [ 145.485126][ C1] run_ksoftirqd+0x25/0x40 [ 145.489529][ C1] smpboot_thread_fn+0x4a3/0x990 [ 145.494469][ C1] kthread+0x4b5/0x4f0 [ 145.498522][ C1] ? cpu_report_death+0x190/0x190 [ 145.503540][ C1] ? kthread_blkcg+0xf0/0xf0 [ 145.508145][ C1] ret_from_fork+0x35/0x40 [ 145.514036][ C1] Kernel Offset: disabled [ 145.518388][ C1] Rebooting in 86400 seconds..