netlink.LinkSubscribe panics on UniFi Cloud Gateway Fiber

[cuonglm]

Hello,

Our project use netlink library to monitor network changes, the code is straight and simple:

https://github.com/Control-D-Inc/ctrld/blob/b9ece6d7b902e9a53f0e1e7618f6bd92eeae2b04/cmd/cli/netlink_linux.go#L14

However, on Ubiquiti Cloud Gateway Fiber device, we received report from our users that the binary panic with this stacktrace:

Jun 29 07:19:57 UCG-Fiber ctrld[1750167]: Jun 29 07:19:57.286 INF [e322ab] REPLY: upstream.0 -> [Edited IP]:33378 (UCG-Fiber): NOERROR
Jun 29 07:19:57 UCG-Fiber ctrld[1750167]: Jun 29 07:19:57.286 DBG [e322ab] received response of 78 bytes in 61.225646ms
Jun 29 07:19:57 UCG-Fiber ctrld[1750167]: panic: runtime error: slice bounds out of range [:16] with capacity 4
Jun 29 07:19:57 UCG-Fiber ctrld[1750167]: goroutine 123 [running]:
Jun 29 07:19:57 UCG-Fiber ctrld[1750167]: github.com/vishvananda/netlink/nl.DeserializeIfInfomsg(...)
Jun 29 07:19:57 UCG-Fiber ctrld[1750167]:         /go/pkg/mod/github.com/vishvananda/[email protected]/nl/nl_linux.go:165
Jun 29 07:19:57 UCG-Fiber ctrld[1750167]: github.com/vishvananda/netlink.linkSubscribeAt.func2()
Jun 29 07:19:57 UCG-Fiber ctrld[1750167]:         /go/pkg/mod/github.com/vishvananda/[email protected]/link_linux.go:2152 +0x2d8
Jun 29 07:19:57 UCG-Fiber ctrld[1750167]: created by github.com/vishvananda/netlink.linkSubscribeAt in goroutine 119
Jun 29 07:19:57 UCG-Fiber ctrld[1750167]:         /go/pkg/mod/github.com/vishvananda/[email protected]/link_linux.go:2120 +0x2b0
Jun 29 07:19:57 UCG-Fiber systemd[1]: ctrld.service: Main process exited, code=exited, status=2/INVALIDARGUMENT
Jun 29 07:19:57 UCG-Fiber systemd[1]: ctrld.service: Failed with result 'exit-code'.
Jun 29 07:19:57 UCG-Fiber systemd[1]: ctrld.service: Consumed 1.029s CPU time.
Jun 29 07:21:57 UCG-Fiber systemd[1]: ctrld.service: Scheduled restart job, restart counter is at 2.
Jun 29 07:21:57 UCG-Fiber systemd[1]: Stopped A highly configurable, multi-protocol DNS forwarding proxy.
Jun 29 07:21:57 UCG-Fiber systemd[1]: ctrld.service: Consumed 1.029s CPU time.
Jun 29 07:21:57 UCG-Fiber systemd[1]: Started A highly configurable, multi-protocol DNS forwarding proxy.

It seems to me that either netlink does not handle the message correctly, or the kernel on Ubiquiti Cloud Gateway Fiber may return an invalid message.