[ OK ] Started Network Time Synchronization. [ OK ] Started Raise network interfaces. [ OK ] Reached target Network. Starting Permit User Sessions... Starting OpenBSD Secure Shell server... [ OK ] Started Permit User Sessions. [ OK ] Started OpenBSD Secure Shell server. [ 14.192222][ C1] random: crng init done [ 14.193914][ C1] random: 7 urandom warning(s) missed due to ratelimiting Warning: Permanently added '10.128.0.3' (ECDSA) to the list of known hosts. [* ] A start job is running for dev-ttyS0.device (8s / 1min 30s) [** ] A start job is running for dev-ttyS0.device (9s / 1min 30s) [*** ] A start job is running for dev-ttyS0.device (9s / 1min 30s) [ *** ] A start job is running for dev-ttyS0.device (10s / 1min 30s) [ *** ] A start job is running for dev-ttyS0.device (10s / 1min 30s) [ ***] A start job is running for dev-ttyS0.device (11s / 1min 30s) [ **] A start job is running for dev-ttyS0.device (12s / 1min 30s) [ *] A start job is running for dev-ttyS0.device (12s / 1min 30s) [ **] A start job is running for dev-ttyS0.device (13s / 1min 30s) [ ***] A start job is running for dev-ttyS0.device (13s / 1min 30s)[ 20.008681][ T22] audit: type=1400 audit(1588839589.433:8): avc: denied { execmem } for pid=404 comm="syz-executor748" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 20.018476][ T413] cgroup1: Unknown subsys name 'perf_event' [ 20.034266][ T415] cgroup1: Unknown subsys name 'perf_event' [ 20.038890][ T412] cgroup1: Unknown subsys name 'perf_event' [ 20.042050][ T416] cgroup1: Unknown subsys name 'perf_event' executing program executing program [ 20.047950][ T414] cgroup1: Unknown subsys name 'perf_event' [ 20.053715][ T415] cgroup1: Unknown subsys name 'net_cls' [ 20.062479][ T412] cgroup1: Unknown subsys name 'net_cls' [ 20.066122][ T417] cgroup1: Unknown subsys name 'perf_event' [ 20.071026][ T413] cgroup1: Unknown subsys name 'net_cls' [ 20.076868][ T416] cgroup1: Unknown subsys name 'net_cls' [ 20.082582][ T414] cgroup1: Unknown subsys name 'net_cls' [ 20.087995][ T417] cgroup1: Unknown subsys name 'net_cls' executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ *** ] A start job is running for dev-ttyS0.device (14s / 1min 30s) [ *** ] A start job is running for dev-ttyS0.device (14s / 1min 30s) [*** ] A start job is running for dev-ttyS0.device (15s / 1min 30s) [** ] A start job is running for dev-ttyS0.device (15s / 1min 30s) [* ] A start job is running for dev-ttyS0.device (16s / 1min 30s)[ 22.708817][ T647] ================================================================== [ 22.716914][ T647] BUG: KASAN: use-after-free in free_netdev+0x176/0x300 [ 22.723831][ T647] Read of size 8 at addr ffff8881cac55538 by task syz-executor748/647 [ 22.731958][ T647] [ 22.734276][ T647] CPU: 1 PID: 647 Comm: syz-executor748 Not tainted 5.4.39-syzkaller-00066-g8c464aedacd3 #0 [ 22.744317][ T647] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 22.754351][ T647] Call Trace: [ 22.757734][ T647] dump_stack+0x14a/0x1ce [ 22.762040][ T647] ? show_regs_print_info+0x12/0x12 [ 22.767209][ T647] ? printk+0xd2/0x114 [ 22.771250][ T647] print_address_description+0x93/0x620 [ 22.776955][ T647] ? slab_free_freelist_hook+0xd0/0x150 [ 22.782476][ T647] ? call_rcu+0x10/0x10 [ 22.786631][ T647] __kasan_report+0x16d/0x1e0 [ 22.791285][ T647] ? free_netdev+0x176/0x300 [ 22.795853][ T647] kasan_report+0x34/0x60 [ 22.800156][ T647] free_netdev+0x176/0x300 [ 22.804545][ T647] netdev_run_todo+0xc38/0xe90 [ 22.809281][ T647] ? netdev_refcnt_read+0x1a0/0x1a0 [ 22.814449][ T647] ? mutex_trylock+0xb0/0xb0 [ 22.819024][ T647] rtnetlink_rcv_msg+0x9a0/0xc60 [ 22.823931][ T647] ? rtnetlink_bind+0x80/0x80 [ 22.828591][ T647] ? unwind_get_return_address+0x48/0x90 [ 22.834190][ T647] ? arch_stack_walk+0xd8/0x120 [ 22.839010][ T647] ? stack_trace_save+0x123/0x1f0 [ 22.844015][ T647] ? stack_trace_snprint+0x150/0x150 [ 22.849271][ T647] ? rhashtable_jhash2+0x1cf/0x2f0 [ 22.854352][ T647] ? jhash+0x740/0x740 [ 22.858509][ T647] ? rht_key_hashfn+0x157/0x240 [ 22.863340][ T647] ? deferred_put_nlk_sk+0x210/0x210 [ 22.868601][ T647] ? jhash+0x740/0x740 [ 22.872641][ T647] ? netlink_hash+0xd0/0xd0 [ 22.877131][ T647] ? __sys_sendmsg+0x2d5/0x3c0 [ 22.882060][ T647] ? do_syscall_64+0xcb/0x150 [ 22.886710][ T647] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 22.892756][ T647] ? __rcu_read_lock+0x50/0x50 [ 22.897492][ T647] netlink_rcv_skb+0x200/0x480 [ 22.902240][ T647] ? rtnetlink_bind+0x80/0x80 [ 22.906886][ T647] ? netlink_ack+0xa90/0xa90 [ 22.911446][ T647] ? __rcu_read_lock+0x50/0x50 [ 22.916178][ T647] ? selinux_vm_enough_memory+0x170/0x170 [ 22.921865][ T647] ? netlink_trim+0x10a/0x230 [ 22.926525][ T647] netlink_unicast+0x8ad/0xa50 [ 22.931268][ T647] ? netlink_detachskb+0x60/0x60 [ 22.936178][ T647] ? __virt_addr_valid+0x1fd/0x290 [ 22.941262][ T647] netlink_sendmsg+0x9de/0xd80 [ 22.946101][ T647] ? netlink_getsockopt+0x8e0/0x8e0 [ 22.951275][ T647] ? import_iovec+0x1c2/0x380 [ 22.955933][ T647] ? security_socket_sendmsg+0xad/0xc0 [ 22.961363][ T647] ? netlink_getsockopt+0x8e0/0x8e0 [ 22.966530][ T647] ____sys_sendmsg+0x58a/0x8d0 [ 22.971266][ T647] ? __sys_sendmsg_sock+0x2b0/0x2b0 [ 22.976434][ T647] __sys_sendmsg+0x2d5/0x3c0 [ 22.980995][ T647] ? ____sys_sendmsg+0x8d0/0x8d0 [ 22.986079][ T647] ? fput_many+0x42/0x1a0 [ 22.990390][ T647] do_syscall_64+0xcb/0x150 [ 22.994879][ T647] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 23.000757][ T647] RIP: 0033:0x447db9 [ 23.004644][ T647] Code: e8 3c e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab 06 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 23.024230][ T647] RSP: 002b:00007f83f92e2ce8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 23.032610][ T647] RAX: ffffffffffffffda RBX: 00000000006ddc68 RCX: 0000000000447db9 [ 23.040659][ T647] RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000005 [ 23.048599][ T647] RBP: 00000000006ddc60 R08: 0000000000000000 R09: 0000000000000000 [ 23.056538][ T647] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006ddc6c [ 23.064492][ T647] R13: 00007ffe7c73456f R14: 00007f83f92e39c0 R15: 20c49ba5e353f7cf [ 23.072448][ T647] [ 23.074750][ T647] Allocated by task 647: [ 23.078964][ T647] __kasan_kmalloc+0x12c/0x1c0 [ 23.083697][ T647] __kmalloc+0xf7/0x2d0 [ 23.087821][ T647] sk_prot_alloc+0xd6/0x290 [ 23.092291][ T647] sk_alloc+0x2e/0x2e0 [ 23.096429][ T647] tun_chr_open+0x77/0x4a0 [ 23.100827][ T647] misc_open+0x356/0x3d0 [ 23.105038][ T647] chrdev_open+0x585/0x640 [ 23.109422][ T647] do_dentry_open+0x8f7/0x1070 [ 23.114155][ T647] path_openat+0x12db/0x3d10 [ 23.118711][ T647] do_filp_open+0x20d/0x440 [ 23.123184][ T647] do_sys_open+0x387/0x7d0 [ 23.127583][ T647] do_syscall_64+0xcb/0x150 [ 23.132056][ T647] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 23.137927][ T647] [ 23.140224][ T647] Freed by task 644: [ 23.144087][ T647] __kasan_slab_free+0x181/0x230 [ 23.149007][ T647] slab_free_freelist_hook+0xd0/0x150 [ 23.154360][ T647] kfree+0x12b/0x600 [ 23.158223][ T647] __sk_destruct+0x3f9/0x480 [ 23.162785][ T647] tun_chr_close+0xb4/0xd0 [ 23.167167][ T647] __fput+0x27d/0x6c0 [ 23.171133][ T647] task_work_run+0x176/0x1a0 [ 23.175689][ T647] prepare_exit_to_usermode+0x286/0x2e0 [ 23.181203][ T647] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 23.187060][ T647] [ 23.189361][ T647] The buggy address belongs to the object at ffff8881cac55000 [ 23.189361][ T647] which belongs to the cache kmalloc-2k of size 2048 [ 23.203394][ T647] The buggy address is located 1336 bytes inside of [ 23.203394][ T647] 2048-byte region [ffff8881cac55000, ffff8881cac55800) [ 23.216801][ T647] The buggy address belongs to the page: [ 23.222414][ T647] page:ffffea00072b1400 refcount:1 mapcount:0 mapping:ffff8881da80c000 index:0x0 compound_mapcount: 0 [ 23.233408][ T647] flags: 0x8000000000010200(slab|head) [ 23.238837][ T647] raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881da80c000 [ 23.247389][ T647] raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000 [ 23.256047][ T647] page dumped because: kasan: bad access detected [ 23.262431][ T647] [ 23.264739][ T647] Memory state around the buggy address: [ 23.270340][ T647] ffff8881cac55400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 23.279323][ T647] ffff8881cac55480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 23.287366][ T647] >ffff8881cac55500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 23.295393][ T647] ^ [ 23.301254][ T647] ffff8881cac55580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb executing program executing program executing program executing program [ 23.309285][ T647] ffff8881cac55600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 23.317337][ T647] ================================================================== [ 23.325363][ T647] Disabling lock debugging due to kernel taint executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program