| Message ID | 20171011182144.08ffc990@xeon-e3 |
|---|---|
| State | RFC, archived |
| Delegated to: | stephen hemminger |
| Headers | show |
| Series | [RFC] iproute2: reject zero length strings for matches | expand |
diff --git a/lib/utils.c b/lib/utils.c index ac155bf5a044..b68a2e0f4a07 100644 --- a/lib/utils.c +++ b/lib/utils.c @@ -733,7 +733,7 @@ int matches(const char *cmd, const char *pattern) { int len = strlen(cmd); - if (len > strlen(pattern)) + if (len == 0 || len > strlen(pattern)) return -1; return memcmp(pattern, cmd, len); }
The ip commands use the function matches() to allow for abbreviations like: $ ip l $ ip r But the function does not check for zero length strings which is potentially error prone (but might also break some power users assumptions). For example: $ 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 This patch checks for zero length strings and never matches the option. $ ip "" Object "" is unknown, try "ip help".