From: Srinivas Dasari <dasaris@xxxxxxxxxxxxxxxx> 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: stable@xxxxxxxxxxxxxxx Signed-off-by: Srinivas Dasari <dasaris@xxxxxxxxxxxxxxxx> Signed-off-by: Jouni Malinen <jouni@xxxxxxxxxxxxxxxx> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Willy Tarreau <w@xxxxxx> --- 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