[ OK ] Started OpenBSD Secure Shell server. [ OK ] Started Getty on tty5. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty4. [ OK ] Started getty on tty2-tty6 if dbus and logind are not available. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.127' (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 syzkaller login: [ 48.922689][ T6822] ================================================================== [ 48.930968][ T6822] BUG: KASAN: use-after-free in tipc_nl_node_dump_monitor_peer+0x566/0x590 [ 48.939596][ T6822] Read of size 2 at addr ffff88809eee8814 by task syz-executor875/6822 [ 48.947809][ T6822] [ 48.950123][ T6822] CPU: 0 PID: 6822 Comm: syz-executor875 Not tainted 5.8.0-rc3-syzkaller #0 [ 48.958773][ T6822] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.968802][ T6822] Call Trace: [ 48.972070][ T6822] dump_stack+0x1f0/0x31e [ 48.976380][ T6822] print_address_description+0x66/0x5a0 [ 48.981900][ T6822] ? vprintk_emit+0x342/0x3c0 [ 48.986566][ T6822] ? printk+0x62/0x83 [ 48.990545][ T6822] ? vprintk_emit+0x339/0x3c0 [ 48.995212][ T6822] kasan_report+0x132/0x1d0 [ 48.999691][ T6822] ? tipc_nl_node_dump_monitor_peer+0x566/0x590 [ 49.005914][ T6822] ? __mutex_lock_common+0x582/0x2fc0 [ 49.011272][ T6822] tipc_nl_node_dump_monitor_peer+0x566/0x590 [ 49.017321][ T6822] genl_lock_dumpit+0x86/0xa0 [ 49.021975][ T6822] netlink_dump+0x4be/0x10d0 [ 49.026562][ T6822] ? __netlink_dump_start+0x530/0x700 [ 49.031926][ T6822] __netlink_dump_start+0x538/0x700 [ 49.037121][ T6822] genl_rcv_msg+0xb03/0xe00 [ 49.041603][ T6822] ? genl_rcv_msg+0xe00/0xe00 [ 49.046266][ T6822] ? genl_start+0x570/0x570 [ 49.050739][ T6822] ? genl_lock_dumpit+0xa0/0xa0 [ 49.055568][ T6822] netlink_rcv_skb+0x190/0x3a0 [ 49.060332][ T6822] ? genl_unbind+0x270/0x270 [ 49.064905][ T6822] genl_rcv+0x24/0x40 [ 49.068876][ T6822] netlink_unicast+0x786/0x940 [ 49.073626][ T6822] netlink_sendmsg+0xa57/0xd70 [ 49.078391][ T6822] ? netlink_getsockopt+0x9e0/0x9e0 [ 49.083586][ T6822] ____sys_sendmsg+0x519/0x800 [ 49.088330][ T6822] ? import_iovec+0x12a/0x2c0 [ 49.092988][ T6822] __sys_sendmsg+0x2b1/0x360 [ 49.097562][ T6822] ? do_raw_spin_unlock+0x134/0x8d0 [ 49.102781][ T6822] ? lock_is_held_type+0x87/0xe0 [ 49.107697][ T6822] ? lock_is_held_type+0x87/0xe0 [ 49.112613][ T6822] ? rcu_read_lock_sched_held+0x2f/0xa0 [ 49.118134][ T6822] ? lock_is_held_type+0x87/0xe0 [ 49.123050][ T6822] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.129091][ T6822] do_syscall_64+0x73/0xe0 [ 49.133485][ T6822] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.139358][ T6822] RIP: 0033:0x4452a9 [ 49.143248][ T6822] Code: Bad RIP value. [ 49.147295][ T6822] RSP: 002b:00007ffd9993f498 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 49.155711][ T6822] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004452a9 [ 49.163661][ T6822] RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000003 [ 49.171654][ T6822] RBP: 000000000000bf02 R08: 0000000000000000 R09: 00000000004002e0 [ 49.179622][ T6822] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402440 [ 49.187570][ T6822] R13: 00000000004024d0 R14: 0000000000000000 R15: 0000000000000000 [ 49.195523][ T6822] [ 49.197840][ T6822] Allocated by task 6823: [ 49.202145][ T6822] __kasan_kmalloc+0x103/0x140 [ 49.207235][ T6822] __alloc_skb+0xde/0x4f0 [ 49.211572][ T6822] netlink_sendmsg+0x7b2/0xd70 [ 49.216319][ T6822] ____sys_sendmsg+0x519/0x800 [ 49.221104][ T6822] __sys_sendmsg+0x2b1/0x360 [ 49.225673][ T6822] do_syscall_64+0x73/0xe0 [ 49.230066][ T6822] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.235924][ T6822] [ 49.238229][ T6822] Freed by task 6823: [ 49.242185][ T6822] __kasan_slab_free+0x114/0x170 [ 49.247095][ T6822] kfree+0x10a/0x220 [ 49.250963][ T6822] __kfree_skb+0x56/0x1c0 [ 49.255266][ T6822] netlink_unicast+0x78e/0x940 [ 49.260000][ T6822] netlink_sendmsg+0xa57/0xd70 [ 49.264744][ T6822] ____sys_sendmsg+0x519/0x800 [ 49.269515][ T6822] __sys_sendmsg+0x2b1/0x360 [ 49.274089][ T6822] do_syscall_64+0x73/0xe0 [ 49.278489][ T6822] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.284375][ T6822] [ 49.286680][ T6822] The buggy address belongs to the object at ffff88809eee8800 [ 49.286680][ T6822] which belongs to the cache kmalloc-512 of size 512 [ 49.300702][ T6822] The buggy address is located 20 bytes inside of [ 49.300702][ T6822] 512-byte region [ffff88809eee8800, ffff88809eee8a00) [ 49.314299][ T6822] The buggy address belongs to the page: [ 49.319911][ T6822] page:ffffea00027bba00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 49.328989][ T6822] flags: 0xfffe0000000200(slab) [ 49.333830][ T6822] raw: 00fffe0000000200 ffffea0002884148 ffffea000288a3c8 ffff8880aa400a80 [ 49.342395][ T6822] raw: 0000000000000000 ffff88809eee8000 0000000100000004 0000000000000000 [ 49.350948][ T6822] page dumped because: kasan: bad access detected [ 49.357352][ T6822] [ 49.359671][ T6822] Memory state around the buggy address: [ 49.365291][ T6822] ffff88809eee8700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc executing program executing program [ 49.373356][ T6822] ffff88809eee8780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 49.381390][ T6822] >ffff88809eee8800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 49.389432][ T6822] ^ [ 49.393994][ T6822] ffff88809eee8880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 49.402041][ T6822] ffff88809eee8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 49.410073][ T6822] ================================================================== [ 49.418104][ T6822] Disabling lock debugging due to kernel taint [ 49.429271][ T6822] Kernel panic - not syncing: panic_on_warn set ... [ 49.435882][ T6822] CPU: 0 PID: 6822 Comm: syz-executor875 Tainted: G B 5.8.0-rc3-syzkaller #0 [ 49.445933][ T6822] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.455978][ T6822] Call Trace: [ 49.459257][ T6822] dump_stack+0x1f0/0x31e [ 49.463567][ T6822] panic+0x264/0x7a0 [ 49.467437][ T6822] ? trace_hardirqs_on+0x30/0x80 [ 49.472356][ T6822] kasan_report+0x1c9/0x1d0 [ 49.476888][ T6822] ? tipc_nl_node_dump_monitor_peer+0x566/0x590 [ 49.483124][ T6822] ? __mutex_lock_common+0x582/0x2fc0 [ 49.488482][ T6822] tipc_nl_node_dump_monitor_peer+0x566/0x590 [ 49.494539][ T6822] genl_lock_dumpit+0x86/0xa0 [ 49.499199][ T6822] netlink_dump+0x4be/0x10d0 [ 49.503767][ T6822] ? __netlink_dump_start+0x530/0x700 [ 49.509118][ T6822] __netlink_dump_start+0x538/0x700 [ 49.514290][ T6822] genl_rcv_msg+0xb03/0xe00 [ 49.518765][ T6822] ? genl_rcv_msg+0xe00/0xe00 [ 49.523409][ T6822] ? genl_start+0x570/0x570 [ 49.527896][ T6822] ? genl_lock_dumpit+0xa0/0xa0 [ 49.532750][ T6822] netlink_rcv_skb+0x190/0x3a0 [ 49.537487][ T6822] ? genl_unbind+0x270/0x270 [ 49.542048][ T6822] genl_rcv+0x24/0x40 [ 49.546002][ T6822] netlink_unicast+0x786/0x940 [ 49.550762][ T6822] netlink_sendmsg+0xa57/0xd70 [ 49.555498][ T6822] ? netlink_getsockopt+0x9e0/0x9e0 [ 49.560668][ T6822] ____sys_sendmsg+0x519/0x800 [ 49.565420][ T6822] ? import_iovec+0x12a/0x2c0 [ 49.570098][ T6822] __sys_sendmsg+0x2b1/0x360 [ 49.574695][ T6822] ? do_raw_spin_unlock+0x134/0x8d0 [ 49.579891][ T6822] ? lock_is_held_type+0x87/0xe0 [ 49.584815][ T6822] ? lock_is_held_type+0x87/0xe0 [ 49.589720][ T6822] ? rcu_read_lock_sched_held+0x2f/0xa0 [ 49.595256][ T6822] ? lock_is_held_type+0x87/0xe0 [ 49.600182][ T6822] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.606228][ T6822] do_syscall_64+0x73/0xe0 [ 49.610620][ T6822] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.616504][ T6822] RIP: 0033:0x4452a9 [ 49.620368][ T6822] Code: Bad RIP value. [ 49.624404][ T6822] RSP: 002b:00007ffd9993f498 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 49.632784][ T6822] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004452a9 [ 49.640726][ T6822] RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000003 [ 49.648681][ T6822] RBP: 000000000000bf02 R08: 0000000000000000 R09: 00000000004002e0 [ 49.656641][ T6822] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402440 [ 49.664594][ T6822] R13: 00000000004024d0 R14: 0000000000000000 R15: 0000000000000000 [ 49.673603][ T6822] Kernel Offset: disabled [ 49.677919][ T6822] Rebooting in 86400 seconds..