Messages in this thread | | | Date | Fri, 13 Oct 2023 09:56:49 +0100 | Subject | Re: [PATCH] tipc: Fix uninit-value access in tipc_nl_node_get_link() | From | Vadim Fedorenko <> |
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On 13/10/2023 08:04, Ma Ke wrote: > Names must be null-terminated strings. If a name which is not > null-terminated is passed through netlink, strstr() and similar > functions can cause buffer overrun. This patch fixes this issue > by returning -EINVAL if a non-null-terminated name is passed. > > Signed-off-by: Ma Ke <make_ruc2021@163.com> > --- > net/tipc/node.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/net/tipc/node.c b/net/tipc/node.c > index 3105abe97bb9..a02bcd7e07d3 100644 > --- a/net/tipc/node.c > +++ b/net/tipc/node.c > @@ -2519,6 +2519,9 @@ int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info) > return -EINVAL; > > name = nla_data(attrs[TIPC_NLA_LINK_NAME]); > + if (name[strnlen(name, > + nla_len(attrs[TIPC_NLA_LINK_NAME]))] != '\0') > + return -EINVAL;
The better choice would be to use strncmp() with limit of TIPC_MAX_LINK_NAME in tipc_node_find_by_name(). This patch fixes tipc_nl_node_get_link(), but the same pattern is used in tipc_nl_node_set_link() and tipc_nl_node_reset_link_stats(), these functions also need improvements. Changes to strncmp() and strnstr() will fix all spots.
> > msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); > if (!msg.skb)
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