[ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty1. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.199' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 60.159619][ T6985] ================================================================== [ 60.168011][ T6985] BUG: KASAN: use-after-free in tipc_nl_node_dump_link+0xdd6/0xdf0 [ 60.175909][ T6985] Read of size 2 at addr ffff88809f17d814 by task syz-executor915/6985 [ 60.184152][ T6985] [ 60.186611][ T6985] CPU: 0 PID: 6985 Comm: syz-executor915 Not tainted 5.8.0-rc2-syzkaller #0 [ 60.195266][ T6985] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.205314][ T6985] Call Trace: executing program [ 60.208608][ T6985] dump_stack+0x18f/0x20d [ 60.212960][ T6985] ? tipc_nl_node_dump_link+0xdd6/0xdf0 [ 60.218706][ T6985] ? tipc_nl_node_dump_link+0xdd6/0xdf0 [ 60.224244][ T6985] print_address_description.constprop.0.cold+0xae/0x436 [ 60.231261][ T6985] ? tipc_nl_node_dump_link+0x279/0xdf0 [ 60.236812][ T6985] ? vprintk_func+0x97/0x1a6 [ 60.241412][ T6985] ? tipc_nl_node_dump_link+0xdd6/0xdf0 [ 60.246955][ T6985] kasan_report.cold+0x1f/0x37 [ 60.251707][ T6985] ? tipc_nl_node_dump_link+0xdd6/0xdf0 [ 60.257248][ T6985] tipc_nl_node_dump_link+0xdd6/0xdf0 [ 60.262611][ T6985] ? __mutex_lock+0x626/0x10d0 [ 60.267461][ T6985] ? tipc_nl_node_reset_link_stats+0xb40/0xb40 [ 60.273641][ T6985] ? check_preemption_disabled+0x38/0x220 [ 60.279379][ T6985] ? rcu_read_lock_sched_held+0x3a/0xb0 [ 60.284922][ T6985] ? kmem_cache_alloc_node_trace+0x3b0/0x400 [ 60.290999][ T6985] ? __kmalloc_node_track_caller+0x38/0x60 [ 60.296794][ T6985] ? kasan_unpoison_shadow+0x33/0x40 [ 60.302080][ T6985] ? __phys_addr+0x9a/0x110 [ 60.306579][ T6985] ? memset+0x20/0x40 [ 60.310555][ T6985] genl_lock_dumpit+0x7f/0xb0 [ 60.315362][ T6985] netlink_dump+0x4cd/0xf60 [ 60.319859][ T6985] ? netlink_insert+0x1670/0x1670 [ 60.324878][ T6985] ? __mutex_unlock_slowpath+0xe2/0x610 [ 60.330471][ T6985] ? genl_start+0x45a/0x6e0 [ 60.334991][ T6985] __netlink_dump_start+0x643/0x900 [ 60.340175][ T6985] ? genl_rcv_msg+0x9e0/0x9e0 [ 60.344842][ T6985] ? tipc_nl_node_reset_link_stats+0xb40/0xb40 [ 60.351128][ T6985] genl_family_rcv_msg_dumpit+0x2ac/0x310 [ 60.356858][ T6985] ? genl_rcv+0x40/0x40 [ 60.361017][ T6985] ? mutex_lock_io_nested+0xf60/0xf60 [ 60.366379][ T6985] ? mark_lock+0xbc/0x1710 [ 60.370786][ T6985] ? genl_rcv_msg+0x9e0/0x9e0 [ 60.375452][ T6985] ? genl_unlock+0x20/0x20 [ 60.379942][ T6985] ? genl_parallel_done+0x170/0x170 [ 60.385128][ T6985] ? __radix_tree_lookup+0x1f3/0x290 [ 60.390427][ T6985] genl_rcv_msg+0x797/0x9e0 [ 60.394966][ T6985] ? genl_family_rcv_msg_attrs_parse.isra.0+0x310/0x310 [ 60.401896][ T6985] ? lock_acquire+0x1f1/0xad0 [ 60.406562][ T6985] ? genl_rcv+0x15/0x40 [ 60.410708][ T6985] ? lock_release+0x8d0/0x8d0 [ 60.415379][ T6985] netlink_rcv_skb+0x15a/0x430 [ 60.420132][ T6985] ? genl_family_rcv_msg_attrs_parse.isra.0+0x310/0x310 [ 60.427052][ T6985] ? netlink_ack+0xa10/0xa10 [ 60.431633][ T6985] genl_rcv+0x24/0x40 [ 60.435609][ T6985] netlink_unicast+0x533/0x7d0 [ 60.440378][ T6985] ? netlink_attachskb+0x810/0x810 [ 60.445477][ T6985] ? _copy_from_iter_full+0x247/0x890 [ 60.450934][ T6985] ? __phys_addr+0x9a/0x110 [ 60.455424][ T6985] ? __phys_addr_symbol+0x2c/0x70 [ 60.460434][ T6985] ? __check_object_size+0x171/0x3e4 [ 60.465726][ T6985] netlink_sendmsg+0x856/0xd90 [ 60.470589][ T6985] ? netlink_unicast+0x7d0/0x7d0 [ 60.475535][ T6985] ? netlink_unicast+0x7d0/0x7d0 [ 60.480484][ T6985] sock_sendmsg+0xcf/0x120 [ 60.484891][ T6985] ____sys_sendmsg+0x6e8/0x810 [ 60.489753][ T6985] ? kernel_sendmsg+0x50/0x50 [ 60.494415][ T6985] ? do_recvmmsg+0x6d0/0x6d0 [ 60.498992][ T6985] ? find_held_lock+0x2d/0x110 [ 60.503743][ T6985] ? lockdep_hardirqs_on_prepare+0x590/0x590 [ 60.509896][ T6985] ? lock_downgrade+0x820/0x820 [ 60.514832][ T6985] ___sys_sendmsg+0xf3/0x170 [ 60.519409][ T6985] ? sendmsg_copy_msghdr+0x160/0x160 [ 60.524681][ T6985] ? debug_object_active_state+0x260/0x350 [ 60.530475][ T6985] ? lock_downgrade+0x820/0x820 [ 60.535319][ T6985] ? _raw_spin_unlock_irqrestore+0x62/0xe0 [ 60.541110][ T6985] ? lockdep_hardirqs_on_prepare+0x3a2/0x590 [ 60.547106][ T6985] ? _raw_spin_unlock_irqrestore+0x9b/0xe0 [ 60.552928][ T6985] ? debug_object_active_state+0x260/0x350 [ 60.558720][ T6985] ? trace_hardirqs_off+0x27/0x210 [ 60.563820][ T6985] ? __fget_light+0x215/0x280 [ 60.568501][ T6985] __sys_sendmsg+0xe5/0x1b0 [ 60.572999][ T6985] ? __sys_sendmsg_sock+0xb0/0xb0 [ 60.578030][ T6985] ? check_preemption_disabled+0x38/0x220 [ 60.583770][ T6985] ? do_syscall_64+0x1c/0xe0 [ 60.588371][ T6985] ? lockdep_hardirqs_on_prepare+0x3a2/0x590 [ 60.594451][ T6985] do_syscall_64+0x60/0xe0 [ 60.598861][ T6985] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 60.604740][ T6985] RIP: 0033:0x4456f9 [ 60.608614][ T6985] Code: Bad RIP value. [ 60.612780][ T6985] RSP: 002b:00007ffd27fd9638 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 60.621216][ T6985] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004456f9 [ 60.629211][ T6985] RDX: 0000000020004014 RSI: 00000000200000c0 RDI: 0000000000000003 [ 60.637170][ T6985] RBP: 000000000000eae6 R08: 0000000000000000 R09: 00000000004002e0 [ 60.645129][ T6985] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402890 [ 60.653088][ T6985] R13: 0000000000402920 R14: 0000000000000000 R15: 0000000000000000 [ 60.661055][ T6985] [ 60.663371][ T6985] Allocated by task 6984: [ 60.667688][ T6985] save_stack+0x1b/0x40 [ 60.671833][ T6985] __kasan_kmalloc.constprop.0+0xc2/0xd0 [ 60.677450][ T6985] __alloc_skb+0xae/0x550 [ 60.681775][ T6985] netlink_sendmsg+0x94f/0xd90 [ 60.686546][ T6985] sock_sendmsg+0xcf/0x120 [ 60.690959][ T6985] ____sys_sendmsg+0x6e8/0x810 [ 60.695719][ T6985] ___sys_sendmsg+0xf3/0x170 [ 60.700294][ T6985] __sys_sendmsg+0xe5/0x1b0 [ 60.704802][ T6985] do_syscall_64+0x60/0xe0 [ 60.709217][ T6985] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 60.715098][ T6985] [ 60.717411][ T6985] Freed by task 6984: [ 60.721380][ T6985] save_stack+0x1b/0x40 [ 60.725644][ T6985] __kasan_slab_free+0xf5/0x140 [ 60.730488][ T6985] kfree+0x103/0x2c0 [ 60.734381][ T6985] skb_release_data+0x6d9/0x910 [ 60.739226][ T6985] consume_skb+0xc2/0x160 [ 60.743542][ T6985] netlink_unicast+0x53b/0x7d0 [ 60.748291][ T6985] netlink_sendmsg+0x856/0xd90 [ 60.753092][ T6985] sock_sendmsg+0xcf/0x120 [ 60.757490][ T6985] ____sys_sendmsg+0x6e8/0x810 [ 60.762248][ T6985] ___sys_sendmsg+0xf3/0x170 [ 60.766831][ T6985] __sys_sendmsg+0xe5/0x1b0 [ 60.771322][ T6985] do_syscall_64+0x60/0xe0 [ 60.775726][ T6985] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 60.781602][ T6985] [ 60.783921][ T6985] The buggy address belongs to the object at ffff88809f17d800 [ 60.783921][ T6985] which belongs to the cache kmalloc-1k of size 1024 [ 60.797968][ T6985] The buggy address is located 20 bytes inside of [ 60.797968][ T6985] 1024-byte region [ffff88809f17d800, ffff88809f17dc00) [ 60.811348][ T6985] The buggy address belongs to the page: [ 60.816969][ T6985] page:ffffea00027c5f40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 60.826057][ T6985] flags: 0xfffe0000000200(slab) [ 60.830979][ T6985] raw: 00fffe0000000200 ffffea000258d608 ffffea00029e00c8 ffff8880aa000c40 [ 60.839637][ T6985] raw: 0000000000000000 ffff88809f17d000 0000000100000002 0000000000000000 [ 60.848293][ T6985] page dumped because: kasan: bad access detected [ 60.854714][ T6985] [ 60.857100][ T6985] Memory state around the buggy address: [ 60.862896][ T6985] ffff88809f17d700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 60.870943][ T6985] ffff88809f17d780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 60.878991][ T6985] >ffff88809f17d800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.887039][ T6985] ^ [ 60.891630][ T6985] ffff88809f17d880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.899776][ T6985] ffff88809f17d900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.907930][ T6985] ================================================================== [ 60.915973][ T6985] Disabling lock debugging due to kernel taint [ 60.932011][ T6985] Kernel panic - not syncing: panic_on_warn set ... [ 60.938594][ T6985] CPU: 0 PID: 6985 Comm: syz-executor915 Tainted: G B 5.8.0-rc2-syzkaller #0 [ 60.948747][ T6985] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.959008][ T6985] Call Trace: [ 60.962307][ T6985] dump_stack+0x18f/0x20d [ 60.966645][ T6985] ? tipc_nl_node_dump_link+0xd40/0xdf0 [ 60.972321][ T6985] panic+0x2e3/0x75c [ 60.976215][ T6985] ? __warn_printk+0xf3/0xf3 [ 60.980793][ T6985] ? preempt_schedule_common+0x59/0xc0 [ 60.986233][ T6985] ? tipc_nl_node_dump_link+0xdd6/0xdf0 [ 60.991889][ T6985] ? preempt_schedule_thunk+0x16/0x18 [ 60.997246][ T6985] ? trace_hardirqs_on+0x55/0x220 [ 61.002253][ T6985] ? tipc_nl_node_dump_link+0xdd6/0xdf0 [ 61.007778][ T6985] ? tipc_nl_node_dump_link+0xdd6/0xdf0 [ 61.013468][ T6985] end_report+0x4d/0x53 [ 61.017610][ T6985] kasan_report.cold+0xd/0x37 [ 61.022289][ T6985] ? tipc_nl_node_dump_link+0xdd6/0xdf0 [ 61.027815][ T6985] tipc_nl_node_dump_link+0xdd6/0xdf0 [ 61.033175][ T6985] ? __mutex_lock+0x626/0x10d0 [ 61.037931][ T6985] ? tipc_nl_node_reset_link_stats+0xb40/0xb40 [ 61.044072][ T6985] ? check_preemption_disabled+0x38/0x220 [ 61.049916][ T6985] ? rcu_read_lock_sched_held+0x3a/0xb0 [ 61.055447][ T6985] ? kmem_cache_alloc_node_trace+0x3b0/0x400 [ 61.061412][ T6985] ? __kmalloc_node_track_caller+0x38/0x60 [ 61.067203][ T6985] ? kasan_unpoison_shadow+0x33/0x40 [ 61.072476][ T6985] ? __phys_addr+0x9a/0x110 [ 61.076984][ T6985] ? memset+0x20/0x40 [ 61.080966][ T6985] genl_lock_dumpit+0x7f/0xb0 [ 61.085629][ T6985] netlink_dump+0x4cd/0xf60 [ 61.090133][ T6985] ? netlink_insert+0x1670/0x1670 [ 61.095253][ T6985] ? __mutex_unlock_slowpath+0xe2/0x610 [ 61.100783][ T6985] ? genl_start+0x45a/0x6e0 [ 61.105270][ T6985] __netlink_dump_start+0x643/0x900 [ 61.110600][ T6985] ? genl_rcv_msg+0x9e0/0x9e0 [ 61.115267][ T6985] ? tipc_nl_node_reset_link_stats+0xb40/0xb40 [ 61.121401][ T6985] genl_family_rcv_msg_dumpit+0x2ac/0x310 [ 61.127101][ T6985] ? genl_rcv+0x40/0x40 [ 61.131362][ T6985] ? mutex_lock_io_nested+0xf60/0xf60 [ 61.136787][ T6985] ? mark_lock+0xbc/0x1710 [ 61.141188][ T6985] ? genl_rcv_msg+0x9e0/0x9e0 [ 61.145850][ T6985] ? genl_unlock+0x20/0x20 [ 61.150256][ T6985] ? genl_parallel_done+0x170/0x170 [ 61.155452][ T6985] ? __radix_tree_lookup+0x1f3/0x290 [ 61.160732][ T6985] genl_rcv_msg+0x797/0x9e0 [ 61.165224][ T6985] ? genl_family_rcv_msg_attrs_parse.isra.0+0x310/0x310 [ 61.172141][ T6985] ? lock_acquire+0x1f1/0xad0 [ 61.176811][ T6985] ? genl_rcv+0x15/0x40 [ 61.180957][ T6985] ? lock_release+0x8d0/0x8d0 [ 61.185618][ T6985] netlink_rcv_skb+0x15a/0x430 [ 61.190376][ T6985] ? genl_family_rcv_msg_attrs_parse.isra.0+0x310/0x310 [ 61.197533][ T6985] ? netlink_ack+0xa10/0xa10 [ 61.202111][ T6985] genl_rcv+0x24/0x40 [ 61.206075][ T6985] netlink_unicast+0x533/0x7d0 [ 61.210909][ T6985] ? netlink_attachskb+0x810/0x810 [ 61.216005][ T6985] ? _copy_from_iter_full+0x247/0x890 [ 61.221358][ T6985] ? __phys_addr+0x9a/0x110 [ 61.225874][ T6985] ? __phys_addr_symbol+0x2c/0x70 [ 61.230883][ T6985] ? __check_object_size+0x171/0x3e4 [ 61.236160][ T6985] netlink_sendmsg+0x856/0xd90 [ 61.240921][ T6985] ? netlink_unicast+0x7d0/0x7d0 [ 61.245845][ T6985] ? netlink_unicast+0x7d0/0x7d0 [ 61.250781][ T6985] sock_sendmsg+0xcf/0x120 [ 61.255193][ T6985] ____sys_sendmsg+0x6e8/0x810 [ 61.259941][ T6985] ? kernel_sendmsg+0x50/0x50 [ 61.264602][ T6985] ? do_recvmmsg+0x6d0/0x6d0 [ 61.269247][ T6985] ? find_held_lock+0x2d/0x110 [ 61.273994][ T6985] ? lockdep_hardirqs_on_prepare+0x590/0x590 [ 61.279976][ T6985] ? lock_downgrade+0x820/0x820 [ 61.284824][ T6985] ___sys_sendmsg+0xf3/0x170 [ 61.289573][ T6985] ? sendmsg_copy_msghdr+0x160/0x160 [ 61.294874][ T6985] ? debug_object_active_state+0x260/0x350 [ 61.300669][ T6985] ? lock_downgrade+0x820/0x820 [ 61.305507][ T6985] ? _raw_spin_unlock_irqrestore+0x62/0xe0 [ 61.311295][ T6985] ? lockdep_hardirqs_on_prepare+0x3a2/0x590 [ 61.317262][ T6985] ? _raw_spin_unlock_irqrestore+0x9b/0xe0 [ 61.323053][ T6985] ? debug_object_active_state+0x260/0x350 [ 61.328911][ T6985] ? trace_hardirqs_off+0x27/0x210 [ 61.334010][ T6985] ? __fget_light+0x215/0x280 [ 61.338674][ T6985] __sys_sendmsg+0xe5/0x1b0 [ 61.343161][ T6985] ? __sys_sendmsg_sock+0xb0/0xb0 [ 61.348290][ T6985] ? check_preemption_disabled+0x38/0x220 [ 61.354003][ T6985] ? do_syscall_64+0x1c/0xe0 [ 61.358582][ T6985] ? lockdep_hardirqs_on_prepare+0x3a2/0x590 [ 61.364546][ T6985] do_syscall_64+0x60/0xe0 [ 61.368948][ T6985] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 61.374822][ T6985] RIP: 0033:0x4456f9 [ 61.378794][ T6985] Code: Bad RIP value. [ 61.382916][ T6985] RSP: 002b:00007ffd27fd9638 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 61.391524][ T6985] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004456f9 [ 61.399478][ T6985] RDX: 0000000020004014 RSI: 00000000200000c0 RDI: 0000000000000003 [ 61.407431][ T6985] RBP: 000000000000eae6 R08: 0000000000000000 R09: 00000000004002e0 [ 61.415428][ T6985] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402890 [ 61.423388][ T6985] R13: 0000000000402920 R14: 0000000000000000 R15: 0000000000000000 [ 61.432726][ T6985] Kernel Offset: disabled [ 61.437052][ T6985] Rebooting in 86400 seconds..