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authorJohannes Berg <johannes.berg@intel.com>2016-09-28 21:44:57 (GMT)
committerJohannes Berg <johannes.berg@intel.com>2016-09-28 21:55:23 (GMT)
commit8f7d99ba85d4d7118a6cf2d0ed9c2ff8e6528679 (patch)
treebaabc7b1c604ee8a97b5dd5833d0569e7fc44b43
parent8564e38206de2ff005a27c8d7c2ce3869a44f0dd (diff)
downloadlinux-8f7d99ba85d4d7118a6cf2d0ed9c2ff8e6528679.tar.xz
cfg80211: wext: really don't store non-WEP keys
Jouni reported that during (repeated) wext_pmf test runs (from the wpa_supplicant hwsim test suite) the kernel crashes. The reason is that after the key is set, the wext code still unnecessarily stores it into the key cache. Despite smatch pointing out an overflow, I failed to identify the possibility for this in the code and missed it during development of the earlier patch series. In order to fix this, simply check that we never store anything but WEP keys into the cache, adding a comment as to why that's enough. Also, since the cache is still allocated early even if it won't be used in many cases, add a comment explaining why - otherwise we'd have to roll back key settings to the driver in case of allocation failures, which is far more difficult. Fixes: 89b706fb28e4 ("cfg80211: reduce connect key caching struct size") Reported-by: Jouni Malinen <j@w1.fi> Bisected-by: Jouni Malinen <j@w1.fi> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
-rw-r--r--net/wireless/wext-compat.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
index 7b97d43..2b096c0 100644
--- a/net/wireless/wext-compat.c
+++ b/net/wireless/wext-compat.c
@@ -406,6 +406,10 @@ static int __cfg80211_set_encryption(struct cfg80211_registered_device *rdev,
if (pairwise && !addr)
return -EINVAL;
+ /*
+ * In many cases we won't actually need this, but it's better
+ * to do it first in case the allocation fails. Don't use wext.
+ */
if (!wdev->wext.keys) {
wdev->wext.keys = kzalloc(sizeof(*wdev->wext.keys),
GFP_KERNEL);
@@ -493,7 +497,13 @@ static int __cfg80211_set_encryption(struct cfg80211_registered_device *rdev,
if (err)
return err;
- if (!addr) {
+ /*
+ * We only need to store WEP keys, since they're the only keys that
+ * can be be set before a connection is established and persist after
+ * disconnecting.
+ */
+ if (!addr && (params->cipher == WLAN_CIPHER_SUITE_WEP40 ||
+ params->cipher == WLAN_CIPHER_SUITE_WEP104)) {
wdev->wext.keys->params[idx] = *params;
memcpy(wdev->wext.keys->data[idx],
params->key, params->key_len);