> Is this safe?
>
> if (strncmp(G.iface, RTA_DATA(attr), len) == 0)
>
> What if RTA_DATA(attr) = "if", len = 2, and G.iface = "if0"?
> Or does kernel pass attr with NUL included?
>
> --
> vda
>
>
>
Yes, it is not safe. It needs to compare their lengths:
int iface_len = strlen(G.iface);
if (iface_len == len && strncmp(G.iface, RTA_DATA(attr), len) == 0)
Attached is a patch. Thanks.
--
max
diff --git a/networking/ifplugd.c b/networking/ifplugd.c
index f398cca..8e21e7c 100644
--- a/networking/ifplugd.c
+++ b/networking/ifplugd.c
@@ -485,8 +485,10 @@ static smallint detect_link(void)
static NOINLINE int check_existence_through_netlink(void)
{
+ int iface_len;
char replybuf[1024];
+ iface_len = strlen(G.iface);
while (1) {
struct nlmsghdr *mhdr;
ssize_t bytes;
@@ -527,7 +529,9 @@ static NOINLINE int check_existence_through_netlink(void)
if (len > IFNAMSIZ)
len = IFNAMSIZ;
- if (strncmp(G.iface, RTA_DATA(attr), len) == 0) {
+ if (iface_len == len &&
+ strncmp(G.iface, RTA_DATA(attr), len) == 0
+ ) {
G.iface_exists = (mhdr->nlmsg_type == RTM_NEWLINK);
}
}
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