Re: [syzbot] BUG: Address fc00:: on device lo is missing its host route.
From: syzbot
Date: Thu Aug 20 2026 - 18:10:06 EST
syzbot has found a reproducer for the following issue on:
HEAD commit: 9d2ed026f031 Merge tag 'sysctl-7.03-rc1' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10661e79580000
kernel config: https://syzkaller.appspot.com/x/.config?x=996f19b48f3c7123
dashboard link: https://syzkaller.appspot.com/bug?extid=ded267b328e950a7c0c4
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10d20415580000
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-9d2ed026.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/dbab070bbde5/vmlinux-9d2ed026.xz
kernel image: https://storage.googleapis.com/syzbot-assets/857014a70033/bzImage-9d2ed026.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ded267b328e950a7c0c4@xxxxxxxxxxxxxxxxxxxxxxxxx
netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
IPv6: BUG: Address fc00:: on device lo is missing its host route.
netdevsim netdevsim0 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim0 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim0 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim0 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
bridge_slave_1: left allmulticast mode
bridge_slave_1: left promiscuous mode
bridge0: port 2(bridge_slave_1) entered disabled state
bridge_slave_0: left allmulticast mode
bridge_slave_0: left promiscuous mode
bridge0: port 1(bridge_slave_0) entered disabled state
bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
bond0 (unregistering): Released all slaves
hsr_slave_0: left promiscuous mode
hsr_slave_1: left promiscuous mode
batman_adv: batadv0: Interface deactivated: batadv_slave_0
batman_adv: batadv0: Removing interface: batadv_slave_0
batman_adv: batadv0: Interface deactivated: batadv_slave_1
batman_adv: batadv0: Removing interface: batadv_slave_1
veth1_macvtap: left promiscuous mode
veth0_macvtap: left promiscuous mode
veth1_vlan: left promiscuous mode
veth0_vlan: left promiscuous mode
team0 (unregistering): Port device team_slave_1 removed
team0 (unregistering): Port device team_slave_0 removed
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If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.