2011-03-26 18:27:09

by Mariusz Kozlowski

Subject: [PATCH] cfg80211:: fix possible NULL pointer dereference

In cfg80211_inform_bss_frame() wiphy is first dereferenced on privsz
initialisation and then it is checked for NULL. This patch fixes that.

Signed-off-by: Mariusz Kozlowski <[email protected]>
---
net/wireless/scan.c | 13 ++++++++++---
1 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index ea427f4..300c11d 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -585,16 +585,23 @@ cfg80211_inform_bss_frame(struct wiphy *wiphy,
struct cfg80211_internal_bss *res;
size_t ielen = len - offsetof(struct ieee80211_mgmt,
u.probe_resp.variable);
- size_t privsz = wiphy->bss_priv_size;
+ size_t privsz;
+
+ if (WARN_ON(!mgmt))
+ return NULL;
+
+ if (WARN_ON(!wiphy))
+ return NULL;

if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC &&
(signal < 0 || signal > 100)))
return NULL;

- if (WARN_ON(!mgmt || !wiphy ||
- len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
+ if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable)))
return NULL;

+ privsz = wiphy->bss_priv_size;
+
res = kzalloc(sizeof(*res) + privsz + ielen, gfp);
if (!res)
return NULL;
--
1.7.0.4

2011-03-27 09:18:31

by Johannes Berg

Subject: Re: [PATCH] cfg80211:: fix possible NULL pointer dereference

On Sat, 2011-03-26 at 19:26 +0100, Mariusz Kozlowski wrote:
> In cfg80211_inform_bss_frame() wiphy is first dereferenced on privsz
> initialisation and then it is checked for NULL. This patch fixes that.
>
> Signed-off-by: Mariusz Kozlowski <[email protected]>

Acked-by: Johannes Berg <[email protected]>

Thanks!

johannes