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[4/4] cfg80211: Validate frequencies nested in NL80211_ATTR_SCAN_FREQUENCIES

Message ID 1499381022-5389-4-git-send-email-jouni@qca.qualcomm.com (mailing list archive)
State Accepted
Delegated to: Johannes Berg
Headers show

Commit Message

Jouni Malinen July 6, 2017, 10:43 p.m. UTC 
From: Srinivas Dasari <dasaris@qti.qualcomm.com>

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@vger.kernel.org
Signed-off-by: Srinivas Dasari <dasaris@qti.qualcomm.com>
Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
---
 net/wireless/nl80211.c | 3 +++
 1 file changed, 3 insertions(+)
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Patch

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 0a63b95..740d3c1 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -6469,6 +6469,9 @@  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++;
 		/*