[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 85.185038][ T30] audit: type=1800 audit(1570689269.249:25): pid=12668 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 85.208413][ T30] audit: type=1800 audit(1570689269.269:26): pid=12668 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 85.246496][ T30] audit: type=1800 audit(1570689269.289:27): pid=12668 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 '10.128.1.10' (ECDSA) to the list of known hosts. 2019/10/10 06:34:43 fuzzer started 2019/10/10 06:34:47 dialing manager at 10.128.0.26:33811 2019/10/10 06:34:48 syscalls: 2412 2019/10/10 06:34:48 code coverage: enabled 2019/10/10 06:34:48 comparison tracing: CONFIG_KCOV_ENABLE_COMPARISONS is not enabled 2019/10/10 06:34:48 extra coverage: enabled 2019/10/10 06:34:48 setuid sandbox: enabled 2019/10/10 06:34:48 namespace sandbox: enabled 2019/10/10 06:34:48 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/10 06:34:48 fault injection: enabled 2019/10/10 06:34:48 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/10 06:34:48 net packet injection: enabled 2019/10/10 06:34:48 net device setup: enabled 2019/10/10 06:34:48 concurrency sanitizer: /sys/kernel/debug/kcsan does not exist syzkaller login: [ 107.271674][T12818] ===================================================== [ 107.278692][T12818] BUG: KMSAN: use-after-free in kfree_skb+0x473/0x4c0 [ 107.285459][T12818] CPU: 1 PID: 12818 Comm: syz-fuzzer Not tainted 5.4.0-rc2+ #0 [ 107.292997][T12818] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 107.303050][T12818] Call Trace: [ 107.306363][T12818] dump_stack+0x191/0x1f0 [ 107.310715][T12818] kmsan_report+0x153/0x2c0 [ 107.315247][T12818] __msan_warning+0x73/0xe0 [ 107.319763][T12818] kmem_cache_free+0x3df/0x2b70 [ 107.324618][T12818] ? kmsan_internal_set_origin+0x6a/0xb0 [ 107.330341][T12818] ? kfree_skb+0x473/0x4c0 [ 107.334770][T12818] ? kmsan_internal_unpoison_shadow+0x42/0x80 [ 107.340869][T12818] kfree_skb+0x473/0x4c0 [ 107.345119][T12818] ? packet_rcv_spkt+0x68d/0x7c0 [ 107.350067][T12818] packet_rcv_spkt+0x68d/0x7c0 [ 107.354841][T12818] ? packet_rcv+0x2110/0x2110 [ 107.359503][T12818] dev_queue_xmit_nit+0x1125/0x1200 [ 107.364708][T12818] dev_hard_start_xmit+0x21e/0xab0 [ 107.369816][T12818] ? kmsan_get_shadow_origin_ptr+0x6e/0x4c0 [ 107.375699][T12818] sch_direct_xmit+0x56c/0x18c0 [ 107.380540][T12818] __dev_queue_xmit+0x212d/0x4200 [ 107.385565][T12818] dev_queue_xmit+0x4b/0x60 [ 107.390047][T12818] ip_finish_output2+0x20d6/0x25d0 [ 107.395148][T12818] ? __msan_metadata_ptr_for_load_2+0x10/0x20 [ 107.401193][T12818] ? nf_ct_deliver_cached_events+0x4d5/0x6e0 [ 107.407161][T12818] __ip_finish_output+0xaf8/0xda0 [ 107.412168][T12818] ip_finish_output+0x2db/0x420 [ 107.417014][T12818] ip_output+0x541/0x610 [ 107.421254][T12818] ? ip_mc_finish_output+0x6d0/0x6d0 [ 107.426528][T12818] ? ip_finish_output+0x420/0x420 [ 107.431535][T12818] __ip_queue_xmit+0x1caf/0x21f0 [ 107.436467][T12818] ? kmsan_get_shadow_origin_ptr+0x6e/0x4c0 [ 107.442361][T12818] ? __msan_metadata_ptr_for_load_8+0x10/0x20 [ 107.448425][T12818] ? should_fail+0x1d2/0xa50 [ 107.453022][T12818] ip_queue_xmit+0xcc/0xf0 [ 107.457424][T12818] ? tcp_v4_inbound_md5_hash+0xd10/0xd10 [ 107.463040][T12818] __tcp_transmit_skb+0x40e3/0x5d90 [ 107.468235][T12818] __tcp_send_ack+0x701/0x840 [ 107.472897][T12818] tcp_send_ack+0x68/0x90 [ 107.477218][T12818] tcp_cleanup_rbuf+0x764/0x800 [ 107.482049][T12818] tcp_recvmsg+0x334d/0x4ff0 [ 107.486652][T12818] ? kmsan_get_shadow_origin_ptr+0x6e/0x4c0 [ 107.492526][T12818] ? tcp_mmap+0x150/0x150 [ 107.496845][T12818] ? tcp_mmap+0x150/0x150 [ 107.501165][T12818] inet_recvmsg+0x237/0x7d0 [ 107.505651][T12818] ? kmsan_get_shadow_origin_ptr+0x6e/0x4c0 [ 107.511522][T12818] ? inet_sendpage+0x2c0/0x2c0 [ 107.516318][T12818] ? inet_sendpage+0x2c0/0x2c0 [ 107.521074][T12818] sock_read_iter+0x5be/0x660 [ 107.525747][T12818] ? kernel_sock_ip_overhead+0x340/0x340 [ 107.531361][T12818] __vfs_read+0xa67/0xc90 [ 107.535684][T12818] vfs_read+0x359/0x6f0 [ 107.539871][T12818] ksys_read+0x265/0x430 [ 107.544098][T12818] __se_sys_read+0x92/0xb0 [ 107.548494][T12818] __x64_sys_read+0x4a/0x70 [ 107.553029][T12818] do_syscall_64+0xb6/0x160 [ 107.557514][T12818] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 107.563383][T12818] RIP: 0033:0x47fd44 [ 107.567257][T12818] Code: ff ff cc cc cc cc e8 9b 40 fb ff 48 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 45 31 d2 45 31 c0 45 31 c9 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 [ 107.586848][T12818] RSP: 002b:000000c42017b710 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 107.595253][T12818] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047fd44 [ 107.603221][T12818] RDX: 0000000000001000 RSI: 000000c4203b2000 RDI: 0000000000000003 [ 107.611210][T12818] RBP: 000000c42017b760 R08: 0000000000000000 R09: 0000000000000000 [ 107.619342][T12818] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004 [ 107.627306][T12818] R13: 0000000000000004 R14: 0000000000000040 R15: ffffffffffffffff [ 107.635265][T12818] [ 107.637580][T12818] Uninit was stored to memory at: [ 107.642585][T12818] kmsan_internal_chain_origin+0xde/0x190 [ 107.648289][T12818] __msan_chain_origin+0x6b/0xe0 [ 107.653201][T12818] ___slab_alloc+0x1dbc/0x1fb0 [ 107.657941][T12818] kmem_cache_alloc+0xade/0xd10 [ 107.662772][T12818] skb_clone+0x326/0x5d0 [ 107.667081][T12818] dev_queue_xmit_nit+0x539/0x1200 [ 107.672177][T12818] dev_hard_start_xmit+0x21e/0xab0 [ 107.677272][T12818] sch_direct_xmit+0x56c/0x18c0 [ 107.682106][T12818] __dev_queue_xmit+0x212d/0x4200 [ 107.687140][T12818] dev_queue_xmit+0x4b/0x60 [ 107.691651][T12818] ip_finish_output2+0x20d6/0x25d0 [ 107.696761][T12818] __ip_finish_output+0xaf8/0xda0 [ 107.701766][T12818] ip_finish_output+0x2db/0x420 [ 107.706599][T12818] ip_output+0x541/0x610 [ 107.710837][T12818] __ip_queue_xmit+0x1caf/0x21f0 [ 107.715781][T12818] ip_queue_xmit+0xcc/0xf0 [ 107.720179][T12818] __tcp_transmit_skb+0x40e3/0x5d90 [ 107.725358][T12818] __tcp_send_ack+0x701/0x840 [ 107.730044][T12818] tcp_send_ack+0x68/0x90 [ 107.734361][T12818] tcp_cleanup_rbuf+0x764/0x800 [ 107.739196][T12818] tcp_recvmsg+0x334d/0x4ff0 [ 107.743799][T12818] inet_recvmsg+0x237/0x7d0 [ 107.748294][T12818] sock_read_iter+0x5be/0x660 [ 107.752951][T12818] __vfs_read+0xa67/0xc90 [ 107.757263][T12818] vfs_read+0x359/0x6f0 [ 107.761398][T12818] ksys_read+0x265/0x430 [ 107.765621][T12818] __se_sys_read+0x92/0xb0 [ 107.770019][T12818] __x64_sys_read+0x4a/0x70 [ 107.774506][T12818] do_syscall_64+0xb6/0x160 [ 107.778997][T12818] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 107.784868][T12818] [ 107.787176][T12818] Uninit was created at: [ 107.791403][T12818] kmsan_internal_poison_shadow+0x60/0x120 [ 107.797195][T12818] kmsan_slab_free+0x8d/0x100 [ 107.801852][T12818] kmem_cache_free_bulk+0x3ad9/0x3f10 [ 107.807237][T12818] __kfree_skb_flush+0xb0/0x100 [ 107.812071][T12818] net_rx_action+0x1a5e/0x1aa0 [ 107.816856][T12818] __do_softirq+0x4a1/0x83a [ 107.821370][T12818] irq_exit+0x230/0x280 [ 107.825506][T12818] do_IRQ+0x123/0x360 [ 107.829490][T12818] ret_from_intr+0x0/0x33 [ 107.833805][T12818] default_idle+0x53/0x90 [ 107.838132][T12818] arch_cpu_idle+0x25/0x30 [ 107.842533][T12818] do_idle+0x1d5/0x780 [ 107.846586][T12818] cpu_startup_entry+0x45/0x50 [ 107.851509][T12818] start_secondary+0x389/0x480 [ 107.856258][T12818] secondary_startup_64+0xa4/0xb0 [ 107.861261][T12818] ===================================================== [ 107.868178][T12818] Disabling lock debugging due to kernel taint [ 107.874312][T12818] Kernel panic - not syncing: panic_on_warn set ... [ 107.880890][T12818] CPU: 1 PID: 12818 Comm: syz-fuzzer Tainted: G B 5.4.0-rc2+ #0 [ 107.889838][T12818] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 107.900154][T12818] Call Trace: [ 107.903560][T12818] dump_stack+0x191/0x1f0 [ 107.907887][T12818] panic+0x3c9/0xc1e [ 107.911790][T12818] kmsan_report+0x2bb/0x2c0 [ 107.916292][T12818] __msan_warning+0x73/0xe0 [ 107.920798][T12818] kmem_cache_free+0x3df/0x2b70 [ 107.925651][T12818] ? kmsan_internal_set_origin+0x6a/0xb0 [ 107.931283][T12818] ? kfree_skb+0x473/0x4c0 [ 107.935700][T12818] ? kmsan_internal_unpoison_shadow+0x42/0x80 [ 107.941766][T12818] kfree_skb+0x473/0x4c0 [ 107.945992][T12818] ? packet_rcv_spkt+0x68d/0x7c0 [ 107.950916][T12818] packet_rcv_spkt+0x68d/0x7c0 [ 107.955672][T12818] ? packet_rcv+0x2110/0x2110 [ 107.960336][T12818] dev_queue_xmit_nit+0x1125/0x1200 [ 107.965532][T12818] dev_hard_start_xmit+0x21e/0xab0 [ 107.970636][T12818] ? kmsan_get_shadow_origin_ptr+0x6e/0x4c0 [ 107.976548][T12818] sch_direct_xmit+0x56c/0x18c0 [ 107.981413][T12818] __dev_queue_xmit+0x212d/0x4200 [ 107.986437][T12818] dev_queue_xmit+0x4b/0x60 [ 107.990964][T12818] ip_finish_output2+0x20d6/0x25d0 [ 107.996069][T12818] ? __msan_metadata_ptr_for_load_2+0x10/0x20 [ 108.002124][T12818] ? nf_ct_deliver_cached_events+0x4d5/0x6e0 [ 108.008101][T12818] __ip_finish_output+0xaf8/0xda0 [ 108.013119][T12818] ip_finish_output+0x2db/0x420 [ 108.017966][T12818] ip_output+0x541/0x610 [ 108.022204][T12818] ? ip_mc_finish_output+0x6d0/0x6d0 [ 108.028359][T12818] ? ip_finish_output+0x420/0x420 [ 108.033720][T12818] __ip_queue_xmit+0x1caf/0x21f0 [ 108.038696][T12818] ? kmsan_get_shadow_origin_ptr+0x6e/0x4c0 [ 108.044599][T12818] ? __msan_metadata_ptr_for_load_8+0x10/0x20 [ 108.050664][T12818] ? should_fail+0x1d2/0xa50 [ 108.055266][T12818] ip_queue_xmit+0xcc/0xf0 [ 108.059678][T12818] ? tcp_v4_inbound_md5_hash+0xd10/0xd10 [ 108.065308][T12818] __tcp_transmit_skb+0x40e3/0x5d90 [ 108.070564][T12818] __tcp_send_ack+0x701/0x840 [ 108.075289][T12818] tcp_send_ack+0x68/0x90 [ 108.079636][T12818] tcp_cleanup_rbuf+0x764/0x800 [ 108.084493][T12818] tcp_recvmsg+0x334d/0x4ff0 [ 108.089293][T12818] ? kmsan_get_shadow_origin_ptr+0x6e/0x4c0 [ 108.095195][T12818] ? tcp_mmap+0x150/0x150 [ 108.099525][T12818] ? tcp_mmap+0x150/0x150 [ 108.103850][T12818] inet_recvmsg+0x237/0x7d0 [ 108.108394][T12818] ? kmsan_get_shadow_origin_ptr+0x6e/0x4c0 [ 108.114599][T12818] ? inet_sendpage+0x2c0/0x2c0 [ 108.119382][T12818] ? inet_sendpage+0x2c0/0x2c0 [ 108.124151][T12818] sock_read_iter+0x5be/0x660 [ 108.128867][T12818] ? kernel_sock_ip_overhead+0x340/0x340 [ 108.134514][T12818] __vfs_read+0xa67/0xc90 [ 108.139362][T12818] vfs_read+0x359/0x6f0 [ 108.143649][T12818] ksys_read+0x265/0x430 [ 108.148024][T12818] __se_sys_read+0x92/0xb0 [ 108.152593][T12818] __x64_sys_read+0x4a/0x70 [ 108.157102][T12818] do_syscall_64+0xb6/0x160 [ 108.161613][T12818] entry_SYSCALL_64_after_hwframe+0x63/0xe7 [ 108.167682][T12818] RIP: 0033:0x47fd44 [ 108.171582][T12818] Code: ff ff cc cc cc cc e8 9b 40 fb ff 48 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 45 31 d2 45 31 c0 45 31 c9 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 [ 108.191290][T12818] RSP: 002b:000000c42017b710 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 108.199845][T12818] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047fd44 [ 108.207823][T12818] RDX: 0000000000001000 RSI: 000000c4203b2000 RDI: 0000000000000003 [ 108.216303][T12818] RBP: 000000c42017b760 R08: 0000000000000000 R09: 0000000000000000 [ 108.224285][T12818] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004 [ 108.232612][T12818] R13: 0000000000000004 R14: 0000000000000040 R15: ffffffffffffffff [ 108.242401][T12818] Kernel Offset: disabled [ 108.246980][T12818] Rebooting in 86400 seconds..