2013-01-25 19:48:57

by Thomas Pedersen

Subject: [PATCH] cfg80211: don't dereference NULL chan

The patch "cfg80211: check radar interface combinations"
would dereference chan even though this may be NULL. Fix a
page fault when adding a new interface by adding a
short-circuit check for NULL.

Signed-off-by: Thomas Pedersen <[email protected]>
---

No action required for this to make it into 3.8, right?

net/wireless/util.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/wireless/util.c b/net/wireless/util.c
index 1c2795d..d1decbc 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -1212,7 +1212,8 @@ int cfg80211_can_use_iftype_chan(struct cfg80211_registered_device *rdev,
case NL80211_IFTYPE_MESH_POINT:
case NL80211_IFTYPE_P2P_GO:
case NL80211_IFTYPE_WDS:
- radar_required = !!(chan->flags & IEEE80211_CHAN_RADAR);
+ radar_required = !!(chan &&
+ chan->flags & IEEE80211_CHAN_RADAR);
break;
case NL80211_IFTYPE_P2P_CLIENT:
case NL80211_IFTYPE_STATION:
--
1.7.10.4

2013-01-25 19:57:35

by Johannes Berg

Subject: Re: [PATCH] cfg80211: don't dereference NULL chan

On Fri, 2013-01-25 at 11:47 -0800, Thomas Pedersen wrote:
> The patch "cfg80211: check radar interface combinations"
> would dereference chan even though this may be NULL. Fix a
> page fault when adding a new interface by adding a
> short-circuit check for NULL.
>
> Signed-off-by: Thomas Pedersen <[email protected]>
> ---
>
> No action required for this to make it into 3.8, right?

It doesn't have to go to 3.8 since the original patch isn't going there,
and I already have the same fix:
683d41ae6755e6ae297ec09603c229795ab9566e

johannes

2013-01-25 20:33:45

by Thomas Pedersen

Subject: Re: [PATCH] cfg80211: don't dereference NULL chan

On Fri, Jan 25, 2013 at 11:57 AM, Johannes Berg
<[email protected]> wrote:
> On Fri, 2013-01-25 at 11:47 -0800, Thomas Pedersen wrote:
>> The patch "cfg80211: check radar interface combinations"
>> would dereference chan even though this may be NULL. Fix a
>> page fault when adding a new interface by adding a
>> short-circuit check for NULL.
>>
>> Signed-off-by: Thomas Pedersen <[email protected]>
>> ---
>>
>> No action required for this to make it into 3.8, right?
>
> It doesn't have to go to 3.8 since the original patch isn't going there,

Oh then -next would be 3.9, duh.

> and I already have the same fix:
> 683d41ae6755e6ae297ec09603c229795ab9566e

Thanks!

--
Thomas