Re: [PATCH net-next] rtnetlink: Move ifm in valid_fdb_dump_legacy to closer to use

[David Miller]

From: David Ahern 
Date: Mon,  8 Oct 2018 13:57:24 -0700

> From: David Ahern 
> 
> Move setting of local variable ifm to after the message parsing in
> valid_fdb_dump_legacy. Avoid potential future use of unchecked variable.
> 
> Fixes: 8dfbda19a21b ("rtnetlink: Move input checking for rtnl_fdb_dump to 
> helper")
> Reported-by: Christian Brauner 
> Signed-off-by: David Ahern 

Applied.

[PATCH net-next] rtnetlink: Move ifm in valid_fdb_dump_legacy to closer to use

[David Ahern]

From: David Ahern 

Move setting of local variable ifm to after the message parsing in
valid_fdb_dump_legacy. Avoid potential future use of unchecked variable.

Fixes: 8dfbda19a21b ("rtnetlink: Move input checking for rtnl_fdb_dump to 
helper")
Reported-by: Christian Brauner 
Signed-off-by: David Ahern 
---
 net/core/rtnetlink.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 6406e26171ff..46328a10034a 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -3857,7 +3857,6 @@ static int valid_fdb_dump_legacy(const struct nlmsghdr 
*nlh,
 int *br_idx, int *brport_idx,
 struct netlink_ext_ack *extack)
 {
-   struct ifinfomsg *ifm = nlmsg_data(nlh);
struct nlattr *tb[IFLA_MAX+1];
int err;
 
@@ -3871,6 +3870,8 @@ static int valid_fdb_dump_legacy(const struct nlmsghdr 
*nlh,
if (nlmsg_len(nlh) != sizeof(struct ndmsg) &&
(nlmsg_len(nlh) != sizeof(struct ndmsg) +
 nla_attr_size(sizeof(u32 {
+   struct ifinfomsg *ifm;
+
err = nlmsg_parse(nlh, sizeof(struct ifinfomsg), tb, IFLA_MAX,
  ifla_policy, extack);
if (err < 0) {
@@ -3880,6 +3881,7 @@ static int valid_fdb_dump_legacy(const struct nlmsghdr 
*nlh,
*br_idx = nla_get_u32(tb[IFLA_MASTER]);
}
 
+   ifm = nlmsg_data(nlh);
*brport_idx = ifm->ifi_index;
}
return 0;
-- 
2.11.0