[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.15.196' (ECDSA) to the list of known hosts. syzkaller login: [ 42.969688][ T7027] IPVS: ftp: loaded support on port[0] = 21 [ 42.970873][ T7021] IPVS: ftp: loaded support on port[0] = 21 [ 42.979237][ T7029] IPVS: ftp: loaded support on port[0] = 21 [ 42.989255][ T7024] IPVS: ftp: loaded support on port[0] = 21 [ 43.002745][ T7028] IPVS: ftp: loaded support on port[0] = 21 [ 43.013629][ T7026] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 45.766141][ T7277] ================================================================== [ 45.774486][ T7277] BUG: KASAN: use-after-free in free_netdev+0x186/0x380 [ 45.781403][ T7277] Read of size 8 at addr ffff8880a28cc6f8 by task syz-executor933/7277 [ 45.789612][ T7277] [ 45.791932][ T7277] CPU: 0 PID: 7277 Comm: syz-executor933 Not tainted 5.7.0-rc5-syzkaller #0 [ 45.800573][ T7277] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.810600][ T7277] Call Trace: [ 45.814214][ T7277] dump_stack+0x1e9/0x30e [ 45.818521][ T7277] print_address_description+0x74/0x5c0 [ 45.824039][ T7277] ? vprintk_emit+0x342/0x3c0 [ 45.828699][ T7277] ? printk+0x62/0x83 [ 45.832664][ T7277] ? trace_irq_disable_rcuidle+0x1f/0x1d0 [ 45.838360][ T7277] __kasan_report+0x103/0x1a0 [ 45.843030][ T7277] ? free_netdev+0x186/0x380 [ 45.847603][ T7277] ? free_netdev+0x186/0x380 [ 45.852167][ T7277] kasan_report+0x4d/0x80 [ 45.856472][ T7277] ? free_netdev+0x186/0x380 [ 45.861038][ T7277] ? netdev_run_todo+0xaca/0xcb0 [ 45.865970][ T7277] ? rtnetlink_rcv_msg+0x890/0xd40 [ 45.871109][ T7277] ? lock_acquire+0x169/0x480 [ 45.875779][ T7277] ? rcu_lock_acquire+0x5/0x30 [ 45.880808][ T7277] ? check_preemption_disabled+0x40/0x240 [ 45.886510][ T7277] ? debug_smp_processor_id+0x5/0x20 [ 45.891781][ T7277] ? netlink_rcv_skb+0x190/0x3a0 [ 45.896692][ T7277] ? rtnetlink_bind+0x80/0x80 [ 45.901523][ T7277] ? netlink_unicast+0x786/0x940 [ 45.906440][ T7277] ? netlink_sendmsg+0xa57/0xd70 [ 45.911361][ T7277] ? netlink_getsockopt+0x9e0/0x9e0 [ 45.916592][ T7277] ? ____sys_sendmsg+0x4f9/0x7c0 [ 45.921537][ T7277] ? import_iovec+0x12a/0x2c0 [ 45.926207][ T7277] ? __sys_sendmsg+0x2a6/0x360 [ 45.931063][ T7277] ? check_preemption_disabled+0x40/0x240 [ 45.936877][ T7277] ? rcu_read_lock_sched_held+0x106/0x170 [ 45.942573][ T7277] ? __fpregs_load_activate+0x168/0x1f0 [ 45.948101][ T7277] ? trace_irq_disable_rcuidle+0x1f/0x1d0 [ 45.953804][ T7277] ? entry_SYSCALL_64_after_hwframe+0x3e/0xb3 [ 45.959848][ T7277] ? do_syscall_64+0xf3/0x1b0 [ 45.964509][ T7277] ? entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 45.970552][ T7277] [ 45.972855][ T7277] Allocated by task 7274: [ 45.977171][ T7277] __kasan_kmalloc+0x114/0x160 [ 45.982617][ T7277] __kmalloc+0x24b/0x330 [ 45.986929][ T7277] sk_prot_alloc+0xa7/0x2b0 [ 45.991580][ T7277] sk_alloc+0x35/0x990 [ 45.995621][ T7277] tun_chr_open+0x77/0x470 [ 46.000046][ T7277] misc_open+0x346/0x3c0 [ 46.004291][ T7277] chrdev_open+0x498/0x580 [ 46.008689][ T7277] do_dentry_open+0x82e/0x10b0 [ 46.013425][ T7277] path_openat+0x2790/0x38b0 [ 46.017993][ T7277] do_filp_open+0x191/0x3a0 [ 46.022617][ T7277] do_sys_openat2+0x463/0x770 [ 46.027266][ T7277] __x64_sys_openat+0x1c8/0x1f0 [ 46.032088][ T7277] do_syscall_64+0xf3/0x1b0 [ 46.036572][ T7277] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 46.042443][ T7277] [ 46.044755][ T7277] Freed by task 7275: [ 46.048718][ T7277] __kasan_slab_free+0x125/0x190 [ 46.053625][ T7277] kfree+0x10a/0x220 [ 46.057501][ T7277] __sk_destruct+0x61d/0x740 [ 46.062063][ T7277] tun_chr_close+0x113/0x130 [ 46.066641][ T7277] __fput+0x2ed/0x750 [ 46.070593][ T7277] task_work_run+0x147/0x1d0 [ 46.075151][ T7277] get_signal+0x1cae/0x1d60 [ 46.079638][ T7277] do_signal+0x33/0x610 [ 46.083773][ T7277] prepare_exit_to_usermode+0x32a/0x600 [ 46.089301][ T7277] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 46.096128][ T7277] [ 46.098435][ T7277] The buggy address belongs to the object at ffff8880a28cc000 [ 46.098435][ T7277] which belongs to the cache kmalloc-4k of size 4096 [ 46.112459][ T7277] The buggy address is located 1784 bytes inside of [ 46.112459][ T7277] 4096-byte region [ffff8880a28cc000, ffff8880a28cd000) [ 46.126075][ T7277] The buggy address belongs to the page: [ 46.131695][ T7277] page:ffffea00028a3300 refcount:1 mapcount:0 mapping:000000000d52f25f index:0x0 head:ffffea00028a3300 order:1 compound_mapcount:0 [ 46.145120][ T7277] flags: 0xfffe0000010200(slab|head) [ 46.150387][ T7277] raw: 00fffe0000010200 ffffea00028cd208 ffffea00022fb188 ffff8880aa402000 [ 46.158952][ T7277] raw: 0000000000000000 ffff8880a28cc000 0000000100000001 0000000000000000 [ 46.167523][ T7277] page dumped because: kasan: bad access detected [ 46.173902][ T7277] [ 46.176223][ T7277] Memory state around the buggy address: [ 46.181847][ T7277] ffff8880a28cc580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.189878][ T7277] ffff8880a28cc600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.197925][ T7277] >ffff8880a28cc680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.205955][ T7277] ^ [ 46.213900][ T7277] ffff8880a28cc700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.222204][ T7277] ffff8880a28cc780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.230247][ T7277] ================================================================== [ 46.238277][ T7277] Disabling lock debugging due to kernel taint [ 46.256002][ T7277] Kernel panic - not syncing: panic_on_warn set ... [ 46.263383][ T7277] CPU: 1 PID: 7277 Comm: syz-executor933 Tainted: G B 5.7.0-rc5-syzkaller #0 [ 46.273670][ T7277] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.283735][ T7277] Call Trace: [ 46.287012][ T7277] dump_stack+0x1e9/0x30e [ 46.291331][ T7277] panic+0x264/0x7a0 [ 46.295219][ T7277] ? trace_hardirqs_on+0x30/0x70 [ 46.300569][ T7277] __kasan_report+0x191/0x1a0 [ 46.305238][ T7277] ? free_netdev+0x186/0x380 [ 46.309830][ T7277] ? free_netdev+0x186/0x380 [ 46.314409][ T7277] kasan_report+0x4d/0x80 [ 46.318721][ T7277] ? free_netdev+0x186/0x380 [ 46.330149][ T7277] ? netdev_run_todo+0xaca/0xcb0 [ 46.335128][ T7277] ? rtnetlink_rcv_msg+0x890/0xd40 [ 46.340236][ T7277] ? lock_acquire+0x169/0x480 [ 46.344912][ T7277] ? rcu_lock_acquire+0x5/0x30 [ 46.349668][ T7277] ? check_preemption_disabled+0x40/0x240 [ 46.355471][ T7277] ? debug_smp_processor_id+0x5/0x20 [ 46.360743][ T7277] ? netlink_rcv_skb+0x190/0x3a0 [ 46.365677][ T7277] ? rtnetlink_bind+0x80/0x80 [ 46.371307][ T7277] ? netlink_unicast+0x786/0x940 [ 46.376237][ T7277] ? netlink_sendmsg+0xa57/0xd70 [ 46.381236][ T7277] ? netlink_getsockopt+0x9e0/0x9e0 [ 46.386411][ T7277] ? ____sys_sendmsg+0x4f9/0x7c0 [ 46.391344][ T7277] ? import_iovec+0x12a/0x2c0 [ 46.396036][ T7277] ? __sys_sendmsg+0x2a6/0x360 [ 46.400787][ T7277] ? check_preemption_disabled+0x40/0x240 [ 46.406505][ T7277] ? rcu_read_lock_sched_held+0x106/0x170 [ 46.412557][ T7277] ? __fpregs_load_activate+0x168/0x1f0 [ 46.418075][ T7277] ? trace_irq_disable_rcuidle+0x1f/0x1d0 [ 46.423779][ T7277] ? entry_SYSCALL_64_after_hwframe+0x3e/0xb3 [ 46.429824][ T7277] ? do_syscall_64+0xf3/0x1b0 [ 46.435257][ T7277] ? entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 46.442689][ T7277] Kernel Offset: disabled [ 46.447109][ T7277] Rebooting in 86400 seconds..