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From:   gregory.greenman@intel.com
To:     johannes@sipsolutions.net
Cc:     linux-wireless@vger.kernel.org,
        Johannes Berg <johannes.berg@intel.com>,
        Roee Goldfiner <roee.h.goldfiner@intel.com>,
        Gregory Greenman <gregory.greenman@intel.com>
Subject: [PATCH 16/19] wifi: iwlwifi: mvm: avoid baid size integer overflow
Date:   Tue, 20 Jun 2023 13:04:02 +0300
Message-Id: <20230620125813.f428c856030d.I2c2bb808e945adb71bc15f5b2bac2d8957ea90eb@changeid>
In-Reply-To: <20230620100405.45117-1-gregory.greenman@intel.com>
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From: Johannes Berg <johannes.berg@intel.com>

Roee reported various hard-to-debug crashes with pings in
EHT aggregation scenarios. Enabling KASAN showed that we
access the BAID allocation out of bounds, and looking at
the code a bit shows that since the reorder buffer entry
(struct iwl_mvm_reorder_buf_entry) is 128 bytes if debug
such as lockdep is enabled, then staring from an agg size
512 we overflow the size calculation, and allocate a much
smaller structure than we should, causing slab corruption
once we initialize this.

Fix this by simply using u32 instead of u16.

Reported-by: Roee Goldfiner <roee.h.goldfiner@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
---
 drivers/net/wireless/intel/iwlwifi/mvm/sta.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
index 37a52ffa8897..3b9a343d4f67 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
@@ -2885,7 +2885,7 @@ int iwl_mvm_sta_rx_agg(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
 	}
 
 	if (iwl_mvm_has_new_rx_api(mvm) && start) {
-		u16 reorder_buf_size = buf_size * sizeof(baid_data->entries[0]);
+		u32 reorder_buf_size = buf_size * sizeof(baid_data->entries[0]);
 
 		/* sparse doesn't like the __align() so don't check */
 #ifndef __CHECKER__
-- 
2.38.1