From: Srinivas Dasari <[email protected]>

commit d7f13f7450369281a5d0ea463cc69890a15923ae upstream.

validate_scan_freqs() retrieves frequencies from attributes
nested in the attribute NL80211_ATTR_SCAN_FREQUENCIES with
nla_get_u32(), which reads 4 bytes from each attribute
without validating the size of data received. Attributes
nested in NL80211_ATTR_SCAN_FREQUENCIES don't have an nla policy.

Validate size of each attribute before parsing to avoid potential buffer
overread.

Fixes: 2a519311926 ("cfg80211/nl80211: scanning (and mac80211 update to use 
it)")
Cc: [email protected]
Signed-off-by: Srinivas Dasari <[email protected]>
Signed-off-by: Jouni Malinen <[email protected]>
Signed-off-by: Johannes Berg <[email protected]>
Signed-off-by: Willy Tarreau <[email protected]>
---
 net/wireless/nl80211.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 32c5443..67705d7 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -5044,6 +5044,10 @@ static int validate_scan_freqs(struct nlattr *freqs)
        struct nlattr *attr1, *attr2;
        int n_channels = 0, tmp1, tmp2;
 
+       nla_for_each_nested(attr1, freqs, tmp1)
+               if (nla_len(attr1) != sizeof(u32))
+                       return 0;
+
        nla_for_each_nested(attr1, freqs, tmp1) {
                n_channels++;
                /*
-- 
2.8.0.rc2.1.gbe9624a

Reply via email to