Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1e9cd487 authored by Anant Thazhemadam's avatar Anant Thazhemadam Committed by Greg Kroah-Hartman
Browse files

nl80211: validate key indexes for cfg80211_registered_device 



commit 2d9463083ce92636a1bdd3e30d1236e3e95d859e upstream

syzbot discovered a bug in which an OOB access was being made because
an unsuitable key_idx value was wrongly considered to be acceptable
while deleting a key in nl80211_del_key().

Since we don't know the cipher at the time of deletion, if
cfg80211_validate_key_settings() were to be called directly in
nl80211_del_key(), even valid keys would be wrongly determined invalid,
and deletion wouldn't occur correctly.
For this reason, a new function - cfg80211_valid_key_idx(), has been
created, to determine if the key_idx value provided is valid or not.
cfg80211_valid_key_idx() is directly called in 2 places -
nl80211_del_key(), and cfg80211_validate_key_settings().

Reported-by: default avatar <syzbot+49d4cab497c2142ee170@syzkaller.appspotmail.com>
Tested-by: default avatar <syzbot+49d4cab497c2142ee170@syzkaller.appspotmail.com>
Suggested-by: default avatarJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarAnant Thazhemadam <anant.thazhemadam@gmail.com>
Link: https://lore.kernel.org/r/20201204215825.129879-1-anant.thazhemadam@gmail.com


Cc: stable@vger.kernel.org
[also disallow IGTK key IDs if no IGTK cipher is supported]
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarZubin Mithra <zsm@chromium.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 3f9186ee

net/wireless/core.h

+2 −0
Original line number Original line Diff line number Diff line
@@ -404,6 +404,8 @@ void cfg80211_sme_abandon_assoc(struct wireless_dev *wdev); 




/* internal helpers */

/* internal helpers */

bool cfg80211_supported_cipher_suite(struct wiphy *wiphy, u32 cipher);

bool cfg80211_supported_cipher_suite(struct wiphy *wiphy, u32 cipher);

bool cfg80211_valid_key_idx(struct cfg80211_registered_device *rdev,

			    int key_idx, bool pairwise);

int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,

int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,

				   struct key_params *params, int key_idx,

				   struct key_params *params, int key_idx,

				   bool pairwise, const u8 *mac_addr);

				   bool pairwise, const u8 *mac_addr);

net/wireless/nl80211.c

+4 −3
Original line number Original line Diff line number Diff line
@@ -3624,9 +3624,6 @@ static int nl80211_del_key(struct sk_buff *skb, struct genl_info *info) 
	if (err)

	if (err)

		return err;

		return err;





	if (key.idx < 0)

		return -EINVAL;



	if (info->attrs[NL80211_ATTR_MAC])

	if (info->attrs[NL80211_ATTR_MAC])

		mac_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);

		mac_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
@@ -3642,6 +3639,10 @@ static int nl80211_del_key(struct sk_buff *skb, struct genl_info *info) 
	    key.type != NL80211_KEYTYPE_GROUP)

	    key.type != NL80211_KEYTYPE_GROUP)

		return -EINVAL;

		return -EINVAL;





	if (!cfg80211_valid_key_idx(rdev, key.idx,

				    key.type == NL80211_KEYTYPE_PAIRWISE))

		return -EINVAL;



	if (!rdev->ops->del_key)

	if (!rdev->ops->del_key)

		return -EOPNOTSUPP;

		return -EOPNOTSUPP;

net/wireless/util.c

+38 −1
Original line number Original line Diff line number Diff line
@@ -214,11 +214,48 @@ bool cfg80211_supported_cipher_suite(struct wiphy *wiphy, u32 cipher) 
	return false;

	return false;

}

}





static bool

cfg80211_igtk_cipher_supported(struct cfg80211_registered_device *rdev)

{

	struct wiphy *wiphy = &rdev->wiphy;

	int i;



	for (i = 0; i < wiphy->n_cipher_suites; i++) {

		switch (wiphy->cipher_suites[i]) {

		case WLAN_CIPHER_SUITE_AES_CMAC:

		case WLAN_CIPHER_SUITE_BIP_CMAC_256:

		case WLAN_CIPHER_SUITE_BIP_GMAC_128:

		case WLAN_CIPHER_SUITE_BIP_GMAC_256:

			return true;

		}

	}



	return false;

}



bool cfg80211_valid_key_idx(struct cfg80211_registered_device *rdev,

			    int key_idx, bool pairwise)

{

	int max_key_idx;



	if (pairwise)

		max_key_idx = 3;

	else if (cfg80211_igtk_cipher_supported(rdev))

		max_key_idx = 5;

	else

		max_key_idx = 3;



	if (key_idx < 0 || key_idx > max_key_idx)

		return false;



	return true;

}



int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,

int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,

				   struct key_params *params, int key_idx,

				   struct key_params *params, int key_idx,

				   bool pairwise, const u8 *mac_addr)

				   bool pairwise, const u8 *mac_addr)

{

{

	if (key_idx < 0 || key_idx > 5)

	if (!cfg80211_valid_key_idx(rdev, key_idx, pairwise))

		return -EINVAL;

		return -EINVAL;





	if (!pairwise && mac_addr && !(rdev->wiphy.flags & WIPHY_FLAG_IBSS_RSN))

	if (!pairwise && mac_addr && !(rdev->wiphy.flags & WIPHY_FLAG_IBSS_RSN))