[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [ 8.132313][ T22] audit: type=1400 audit(1583584048.375:10): avc: denied { watch } for pid=1795 comm="restorecond" path="/root/.ssh" dev="sda1" ino=16179 scontext=system_u:system_r:kernel_t:s0 tcontext=unconfined_u:object_r:ssh_home_t:s0 tclass=dir permissive=1 [ 8.136726][ T22] audit: type=1400 audit(1583584048.375:11): avc: denied { watch } for pid=1795 comm="restorecond" path="/etc/selinux/restorecond.conf" dev="sda1" ino=2280 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 10.921214][ T22] audit: type=1400 audit(1583584051.155:12): avc: denied { map } for pid=1864 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 Warning: Permanently added '10.128.0.241' (ECDSA) to the list of known hosts. [ 22.809593][ T22] audit: type=1400 audit(1583584063.045:13): avc: denied { map } for pid=1882 comm="syz-executor878" path="/root/syz-executor878224149" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 22.834303][ T22] audit: type=1400 audit(1583584063.075:14): avc: denied { create } for pid=1890 comm="syz-executor878" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 executing program executing program [ 22.863427][ T22] audit: type=1400 audit(1583584063.075:15): avc: denied { write } for pid=1889 comm="syz-executor878" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 [ 22.888275][ T22] audit: type=1400 audit(1583584063.075:16): avc: denied { read } for pid=1889 comm="syz-executor878" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 24.691509][ T2020] ================================================================== [ 24.699650][ T2020] BUG: KASAN: use-after-free in free_netdev+0x186/0x300 [ 24.706622][ T2020] Read of size 8 at addr ffff8881cdaf54f0 by task syz-executor878/2020 [ 24.714928][ T2020] [ 24.717293][ T2020] CPU: 1 PID: 2020 Comm: syz-executor878 Not tainted 5.4.24-syzkaller-00181-g3334f0da669e #0 [ 24.727630][ T2020] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 24.737676][ T2020] Call Trace: [ 24.740988][ T2020] dump_stack+0x1b0/0x228 [ 24.745307][ T2020] ? show_regs_print_info+0x18/0x18 [ 24.750486][ T2020] ? vprintk_func+0x105/0x110 [ 24.755144][ T2020] ? printk+0xc0/0x109 [ 24.759410][ T2020] print_address_description+0x96/0x5d0 [ 24.764937][ T2020] ? devkmsg_release+0x127/0x127 [ 24.769913][ T2020] ? call_rcu+0x10/0x10 [ 24.774050][ T2020] __kasan_report+0x14b/0x1c0 [ 24.778706][ T2020] ? free_netdev+0x186/0x300 [ 24.783277][ T2020] kasan_report+0x26/0x50 [ 24.787587][ T2020] __asan_report_load8_noabort+0x14/0x20 [ 24.793198][ T2020] free_netdev+0x186/0x300 [ 24.797596][ T2020] netdev_run_todo+0xbc4/0xe00 [ 24.802339][ T2020] ? netdev_refcnt_read+0x1c0/0x1c0 [ 24.807520][ T2020] ? mutex_trylock+0xb0/0xb0 [ 24.812091][ T2020] ? netlink_net_capable+0x124/0x160 [ 24.817356][ T2020] rtnetlink_rcv_msg+0x963/0xc20 [ 24.822273][ T2020] ? is_bpf_text_address+0x2c8/0x2e0 [ 24.827543][ T2020] ? __kernel_text_address+0x9a/0x110 [ 24.832986][ T2020] ? rtnetlink_bind+0x80/0x80 [ 24.837698][ T2020] ? arch_stack_walk+0x98/0xe0 [ 24.842444][ T2020] ? __rcu_read_lock+0x50/0x50 [ 24.847303][ T2020] ? avc_has_perm_noaudit+0x2fc/0x3f0 [ 24.852703][ T2020] ? rhashtable_jhash2+0x1f1/0x330 [ 24.857794][ T2020] ? jhash+0x750/0x750 [ 24.861844][ T2020] ? rht_key_hashfn+0x157/0x240 [ 24.866721][ T2020] ? deferred_put_nlk_sk+0x200/0x200 [ 24.872035][ T2020] ? __alloc_skb+0x109/0x540 [ 24.876609][ T2020] ? jhash+0x750/0x750 [ 24.880947][ T2020] ? netlink_hash+0xd0/0xd0 [ 24.885610][ T2020] ? avc_has_perm+0x15f/0x260 [ 24.890373][ T2020] ? __rcu_read_lock+0x50/0x50 [ 24.895349][ T2020] netlink_rcv_skb+0x1f0/0x460 [ 24.900102][ T2020] ? rtnetlink_bind+0x80/0x80 [ 24.904772][ T2020] ? netlink_ack+0xa80/0xa80 [ 24.909346][ T2020] ? netlink_autobind+0x1c0/0x1c0 [ 24.914354][ T2020] ? __rcu_read_lock+0x50/0x50 [ 24.919188][ T2020] ? selinux_vm_enough_memory+0x160/0x160 [ 24.924938][ T2020] rtnetlink_rcv+0x1c/0x20 [ 24.929376][ T2020] netlink_unicast+0x87c/0xa20 [ 24.934122][ T2020] ? netlink_detachskb+0x60/0x60 [ 24.939128][ T2020] ? security_netlink_send+0xab/0xc0 [ 24.944403][ T2020] netlink_sendmsg+0x9a7/0xd40 [ 24.949154][ T2020] ? netlink_getsockopt+0x900/0x900 [ 24.954369][ T2020] ? security_socket_sendmsg+0xad/0xc0 [ 24.959874][ T2020] ? netlink_getsockopt+0x900/0x900 [ 24.965058][ T2020] ____sys_sendmsg+0x56f/0x860 [ 24.969807][ T2020] ? __sys_sendmsg_sock+0x2a0/0x2a0 [ 24.975108][ T2020] ? __fdget+0x17c/0x200 [ 24.979364][ T2020] __sys_sendmsg+0x26a/0x350 [ 24.983935][ T2020] ? errseq_set+0x102/0x140 [ 24.988417][ T2020] ? ____sys_sendmsg+0x860/0x860 [ 24.993336][ T2020] ? __rcu_read_lock+0x50/0x50 [ 24.998133][ T2020] ? alloc_file_pseudo+0x282/0x310 [ 25.003272][ T2020] ? __kasan_check_write+0x14/0x20 [ 25.008376][ T2020] ? __kasan_check_write+0x14/0x20 [ 25.013601][ T2020] ? __fpregs_load_activate+0x2fc/0x3b0 [ 25.019217][ T2020] ? switch_fpu_return+0x10/0x10 [ 25.024182][ T2020] ? __kasan_check_read+0x11/0x20 [ 25.029213][ T2020] ? fput_many+0x47/0x1a0 [ 25.033557][ T2020] __x64_sys_sendmsg+0x7f/0x90 [ 25.038341][ T2020] do_syscall_64+0xc0/0x100 [ 25.042866][ T2020] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 25.048739][ T2020] RIP: 0033:0x4483b9 [ 25.052618][ T2020] Code: e8 ac e7 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 4b 06 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 25.072206][ T2020] RSP: 002b:00007f11fb1cbd98 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 25.080683][ T2020] RAX: ffffffffffffffda RBX: 00000000006e3a28 RCX: 00000000004483b9 [ 25.088917][ T2020] RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000005 [ 25.097099][ T2020] RBP: 00000000006e3a20 R08: 0000000000000000 R09: 0000000000000000 [ 25.105223][ T2020] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006e3a2c [ 25.113424][ T2020] R13: 0000003065736f72 R14: 0000000000000000 R15: 0000000000000000 [ 25.121500][ T2020] [ 25.123814][ T2020] Allocated by task 2020: [ 25.128134][ T2020] __kasan_kmalloc+0x117/0x1b0 [ 25.132917][ T2020] kasan_kmalloc+0x9/0x10 [ 25.137283][ T2020] __kmalloc+0x102/0x310 [ 25.141510][ T2020] sk_prot_alloc+0x11c/0x2f0 [ 25.146083][ T2020] sk_alloc+0x35/0x300 [ 25.150154][ T2020] tun_chr_open+0x7b/0x4a0 [ 25.154565][ T2020] misc_open+0x3ea/0x440 [ 25.158863][ T2020] chrdev_open+0x60a/0x670 [ 25.163261][ T2020] do_dentry_open+0x8f7/0x1070 [ 25.168008][ T2020] vfs_open+0x73/0x80 [ 25.172148][ T2020] path_openat+0x1681/0x42d0 [ 25.176719][ T2020] do_filp_open+0x1f7/0x430 [ 25.181203][ T2020] do_sys_open+0x36f/0x7a0 [ 25.185602][ T2020] __x64_sys_openat+0xa2/0xb0 [ 25.190348][ T2020] do_syscall_64+0xc0/0x100 [ 25.194834][ T2020] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 25.200702][ T2020] [ 25.203012][ T2020] Freed by task 2019: [ 25.206977][ T2020] __kasan_slab_free+0x168/0x220 [ 25.212185][ T2020] kasan_slab_free+0xe/0x10 [ 25.216720][ T2020] kfree+0x170/0x6d0 [ 25.220597][ T2020] __sk_destruct+0x45f/0x4e0 [ 25.225168][ T2020] __sk_free+0x35d/0x430 [ 25.229392][ T2020] sk_free+0x45/0x50 [ 25.233268][ T2020] __tun_detach+0x15d0/0x1a40 [ 25.237926][ T2020] tun_chr_close+0xb8/0xd0 [ 25.242323][ T2020] __fput+0x295/0x710 [ 25.246285][ T2020] ____fput+0x15/0x20 [ 25.250250][ T2020] task_work_run+0x176/0x1a0 [ 25.254824][ T2020] prepare_exit_to_usermode+0x2d8/0x370 [ 25.260609][ T2020] syscall_return_slowpath+0x6f/0x500 [ 25.265960][ T2020] do_syscall_64+0xe8/0x100 [ 25.270548][ T2020] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 25.276564][ T2020] [ 25.278875][ T2020] The buggy address belongs to the object at ffff8881cdaf5000 [ 25.278875][ T2020] which belongs to the cache kmalloc-2k of size 2048 [ 25.293245][ T2020] The buggy address is located 1264 bytes inside of [ 25.293245][ T2020] 2048-byte region [ffff8881cdaf5000, ffff8881cdaf5800) [ 25.306672][ T2020] The buggy address belongs to the page: [ 25.312496][ T2020] page:ffffea000736bc00 refcount:1 mapcount:0 mapping:ffff8881da802800 index:0x0 compound_mapcount: 0 [ 25.323408][ T2020] flags: 0x8000000000010200(slab|head) [ 25.328882][ T2020] raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881da802800 [ 25.337623][ T2020] raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000 [ 25.346354][ T2020] page dumped because: kasan: bad access detected [ 25.352907][ T2020] [ 25.355221][ T2020] Memory state around the buggy address: [ 25.360839][ T2020] ffff8881cdaf5380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 25.368927][ T2020] ffff8881cdaf5400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 25.376976][ T2020] >ffff8881cdaf5480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 25.385023][ T2020] ^ executing program executing program executing program [ 25.392948][ T2020] ffff8881cdaf5500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 25.401084][ T2020] ffff8881cdaf5580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 25.409362][ T2020] ================================================================== [ 25.417541][ T2020] 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