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authorLin Ma <linma@zju.edu.cn>2023-07-26 10:53:14 +0300
committerJakub Kicinski <kuba@kernel.org>2023-07-28 03:14:01 +0300
commitd73ef2d69c0dba5f5a1cb9600045c873bab1fb7f (patch)
treea7b16251ebaadfff4ebfe14b31042f9e77e251d5 /net/core
parent57012c57536f8814dec92e74197ee96c3498d24e (diff)
downloadlinux-d73ef2d69c0dba5f5a1cb9600045c873bab1fb7f.tar.xz
rtnetlink: let rtnl_bridge_setlink checks IFLA_BRIDGE_MODE length
There are totally 9 ndo_bridge_setlink handlers in the current kernel, which are 1) bnxt_bridge_setlink, 2) be_ndo_bridge_setlink 3) i40e_ndo_bridge_setlink 4) ice_bridge_setlink 5) ixgbe_ndo_bridge_setlink 6) mlx5e_bridge_setlink 7) nfp_net_bridge_setlink 8) qeth_l2_bridge_setlink 9) br_setlink. By investigating the code, we find that 1-7 parse and use nlattr IFLA_BRIDGE_MODE but 3 and 4 forget to do the nla_len check. This can lead to an out-of-attribute read and allow a malformed nlattr (e.g., length 0) to be viewed as a 2 byte integer. To avoid such issues, also for other ndo_bridge_setlink handlers in the future. This patch adds the nla_len check in rtnl_bridge_setlink and does an early error return if length mismatches. To make it works, the break is removed from the parsing for IFLA_BRIDGE_FLAGS to make sure this nla_for_each_nested iterates every attribute. Fixes: b1edc14a3fbf ("ice: Implement ice_bridge_getlink and ice_bridge_setlink") Fixes: 51616018dd1b ("i40e: Add support for getlink, setlink ndo ops") Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lin Ma <linma@zju.edu.cn> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Hangbin Liu <liuhangbin@gmail.com> Link: https://lore.kernel.org/r/20230726075314.1059224-1-linma@zju.edu.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/rtnetlink.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 3ad4e030846d..aef25aa5cf1d 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -5140,13 +5140,17 @@ static int rtnl_bridge_setlink(struct sk_buff *skb, struct nlmsghdr *nlh,
br_spec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_AF_SPEC);
if (br_spec) {
nla_for_each_nested(attr, br_spec, rem) {
- if (nla_type(attr) == IFLA_BRIDGE_FLAGS) {
+ if (nla_type(attr) == IFLA_BRIDGE_FLAGS && !have_flags) {
if (nla_len(attr) < sizeof(flags))
return -EINVAL;
have_flags = true;
flags = nla_get_u16(attr);
- break;
+ }
+
+ if (nla_type(attr) == IFLA_BRIDGE_MODE) {
+ if (nla_len(attr) < sizeof(u16))
+ return -EINVAL;
}
}
}