On Mon, 15 Jul 2019 20:04:30 +0200 Matteo Croce <mcr...@redhat.com> wrote:
> iproute has an utility function which checks if a string is a prefix for > another one, to allow use of abbreviated commands, e.g. 'addr' or 'a' > instead of 'address'. > > This routine unfortunately considers an empty string as prefix > of any pattern, leading to undefined behaviour when an empty > argument is passed to ip: > > # ip '' > 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group > default qlen 1000 > link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 > inet 127.0.0.1/8 scope host lo > valid_lft forever preferred_lft forever > inet6 ::1/128 scope host > valid_lft forever preferred_lft forever > > # tc '' > qdisc noqueue 0: dev lo root refcnt 2 > > # ip address add 192.0.2.0/24 '' 198.51.100.1 dev dummy0 > # ip addr show dev dummy0 > 6: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default > qlen 1000 > link/ether 02:9d:5e:e9:3f:c0 brd ff:ff:ff:ff:ff:ff > inet 192.0.2.0/24 brd 198.51.100.1 scope global dummy0 > valid_lft forever preferred_lft forever > > Rewrite matches() so it takes care of an empty input, and doesn't > scan the input strings three times: the actual implementation > does 2 strlen and a memcpy to accomplish the same task. > > Signed-off-by: Matteo Croce <mcr...@redhat.com> Thanks for following up. Applied
