* [PATCH] net: bridge: fix potential NULL pointer dereference
@ 2017-06-05 21:30 Gustavo A. R. Silva
2017-06-05 22:05 ` Nikolay Aleksandrov
0 siblings, 1 reply; 6+ messages in thread
From: Gustavo A. R. Silva @ 2017-06-05 21:30 UTC (permalink / raw)
To: Stephen Hemminger, David S. Miller
Cc: bridge, netdev, linux-kernel, Gustavo A. R. Silva
Add NULL check before dereferencing pointer _p_ inside br_afspec().
Addresses-Coverity-ID: 1401872
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
---
net/bridge/br_netlink.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 1e63ec4..ad85a9c 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -776,7 +776,7 @@ int br_setlink(struct net_device *dev, struct nlmsghdr *nlh, u16 flags)
goto out;
}
- if (afspec) {
+ if (p && afspec) {
err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
afspec, RTM_SETLINK);
}
--
2.5.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] net: bridge: fix potential NULL pointer dereference
2017-06-05 21:30 [PATCH] net: bridge: fix potential NULL pointer dereference Gustavo A. R. Silva
@ 2017-06-05 22:05 ` Nikolay Aleksandrov
2017-06-05 22:26 ` [PATCH net] net: bridge: fix a null pointer dereference in br_afspec Nikolay Aleksandrov
2017-06-06 3:13 ` [PATCH] net: bridge: fix potential NULL pointer dereference Gustavo A. R. Silva
0 siblings, 2 replies; 6+ messages in thread
From: Nikolay Aleksandrov @ 2017-06-05 22:05 UTC (permalink / raw)
To: Gustavo A. R. Silva, Stephen Hemminger, David S. Miller
Cc: bridge, netdev, roopa
On 06/06/17 00:30, Gustavo A. R. Silva wrote:
> Add NULL check before dereferencing pointer _p_ inside br_afspec().
>
> Addresses-Coverity-ID: 1401872
> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
> ---
> net/bridge/br_netlink.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
> index 1e63ec4..ad85a9c 100644
> --- a/net/bridge/br_netlink.c
> +++ b/net/bridge/br_netlink.c
> @@ -776,7 +776,7 @@ int br_setlink(struct net_device *dev, struct nlmsghdr *nlh, u16 flags)
> goto out;
> }
>
> - if (afspec) {
> + if (p && afspec) {
> err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
> afspec, RTM_SETLINK);
> }
>
While I see a possible issue with the new bridge tunnel code (+CC Roopa), this is
the wrong fix because there are legitimate use cases where p is null and br_afspec
is called.
We need to change the p->flags check in br_afspec()'s IFLA_BRIDGE_VLAN_TUNNEL_INFO case
to check for a NULL p first.
Thanks for the report!
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH net] net: bridge: fix a null pointer dereference in br_afspec
2017-06-05 22:05 ` Nikolay Aleksandrov
@ 2017-06-05 22:26 ` Nikolay Aleksandrov
2017-06-06 5:28 ` Roopa Prabhu
2017-06-06 20:06 ` David Miller
2017-06-06 3:13 ` [PATCH] net: bridge: fix potential NULL pointer dereference Gustavo A. R. Silva
1 sibling, 2 replies; 6+ messages in thread
From: Nikolay Aleksandrov @ 2017-06-05 22:26 UTC (permalink / raw)
To: netdev; +Cc: roopa, davem, stephen, garsilva, bridge, Nikolay Aleksandrov
We might call br_afspec() with p == NULL which is a valid use case if
the action is on the bridge device itself, but the bridge tunnel code
dereferences the p pointer without checking, so check if p is null
first.
Reported-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Fixes: efa5356b0d97 ("bridge: per vlan dst_metadata netlink support")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
---
net/bridge/br_netlink.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 1e63ec466d7c..3bcda556971e 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -595,7 +595,7 @@ static int br_afspec(struct net_bridge *br,
err = 0;
switch (nla_type(attr)) {
case IFLA_BRIDGE_VLAN_TUNNEL_INFO:
- if (!(p->flags & BR_VLAN_TUNNEL))
+ if (!p || !(p->flags & BR_VLAN_TUNNEL))
return -EINVAL;
err = br_parse_vlan_tunnel_info(attr, &tinfo_curr);
if (err)
--
2.1.4
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH net] net: bridge: fix a null pointer dereference in br_afspec
2017-06-05 22:26 ` [PATCH net] net: bridge: fix a null pointer dereference in br_afspec Nikolay Aleksandrov
@ 2017-06-06 5:28 ` Roopa Prabhu
2017-06-06 20:06 ` David Miller
1 sibling, 0 replies; 6+ messages in thread
From: Roopa Prabhu @ 2017-06-06 5:28 UTC (permalink / raw)
To: Nikolay Aleksandrov
Cc: netdev@vger.kernel.org, bridge, garsilva, davem@davemloft.net
On Mon, Jun 5, 2017 at 3:26 PM, Nikolay Aleksandrov
<nikolay@cumulusnetworks.com> wrote:
> We might call br_afspec() with p == NULL which is a valid use case if
> the action is on the bridge device itself, but the bridge tunnel code
> dereferences the p pointer without checking, so check if p is null
> first.
>
> Reported-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
> Fixes: efa5356b0d97 ("bridge: per vlan dst_metadata netlink support")
> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Thanks Nikolay.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH net] net: bridge: fix a null pointer dereference in br_afspec
2017-06-05 22:26 ` [PATCH net] net: bridge: fix a null pointer dereference in br_afspec Nikolay Aleksandrov
2017-06-06 5:28 ` Roopa Prabhu
@ 2017-06-06 20:06 ` David Miller
1 sibling, 0 replies; 6+ messages in thread
From: David Miller @ 2017-06-06 20:06 UTC (permalink / raw)
To: nikolay; +Cc: netdev, roopa, stephen, garsilva, bridge
From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Date: Tue, 6 Jun 2017 01:26:24 +0300
> We might call br_afspec() with p == NULL which is a valid use case if
> the action is on the bridge device itself, but the bridge tunnel code
> dereferences the p pointer without checking, so check if p is null
> first.
>
> Reported-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
> Fixes: efa5356b0d97 ("bridge: per vlan dst_metadata netlink support")
> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Applied and queued up for -stable, thanks Nikolay.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] net: bridge: fix potential NULL pointer dereference
2017-06-05 22:05 ` Nikolay Aleksandrov
2017-06-05 22:26 ` [PATCH net] net: bridge: fix a null pointer dereference in br_afspec Nikolay Aleksandrov
@ 2017-06-06 3:13 ` Gustavo A. R. Silva
1 sibling, 0 replies; 6+ messages in thread
From: Gustavo A. R. Silva @ 2017-06-06 3:13 UTC (permalink / raw)
To: Nikolay Aleksandrov
Cc: Stephen Hemminger, David S. Miller, bridge, netdev, roopa
Hi Nikolay,
Quoting Nikolay Aleksandrov <nikolay@cumulusnetworks.com>:
> On 06/06/17 00:30, Gustavo A. R. Silva wrote:
>> Add NULL check before dereferencing pointer _p_ inside br_afspec().
>>
>> Addresses-Coverity-ID: 1401872
>> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
>> ---
>> net/bridge/br_netlink.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
>> index 1e63ec4..ad85a9c 100644
>> --- a/net/bridge/br_netlink.c
>> +++ b/net/bridge/br_netlink.c
>> @@ -776,7 +776,7 @@ int br_setlink(struct net_device *dev, struct
>> nlmsghdr *nlh, u16 flags)
>> goto out;
>> }
>>
>> - if (afspec) {
>> + if (p && afspec) {
>> err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
>> afspec, RTM_SETLINK);
>> }
>>
>
> While I see a possible issue with the new bridge tunnel code (+CC
> Roopa), this is
> the wrong fix because there are legitimate use cases where p is null
> and br_afspec
> is called.
> We need to change the p->flags check in br_afspec()'s
> IFLA_BRIDGE_VLAN_TUNNEL_INFO case
> to check for a NULL p first.
>
You're right. I got it.
> Thanks for the report!
Sure thing, glad to help.
Thank you!
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-06-06 20:06 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-06-05 21:30 [PATCH] net: bridge: fix potential NULL pointer dereference Gustavo A. R. Silva
2017-06-05 22:05 ` Nikolay Aleksandrov
2017-06-05 22:26 ` [PATCH net] net: bridge: fix a null pointer dereference in br_afspec Nikolay Aleksandrov
2017-06-06 5:28 ` Roopa Prabhu
2017-06-06 20:06 ` David Miller
2017-06-06 3:13 ` [PATCH] net: bridge: fix potential NULL pointer dereference Gustavo A. R. Silva
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