Subject: [PATCH AUTOSEL 5.4 291/350] iwlwifi: mvm: fix unaligned read of rx_pkt_status

From: Sasha Levin <[email-masked]>
Date: Tue, 10 Dec 2019 16:06:36 -0500

From: Wang Xuerui <[email-masked]>

[ Upstream commit c5aaa8be29b25dfe1731e9a8b19fd91b7b789ee3 ]

This is present since the introduction of iwlmvm.
Example stack trace on MIPS:

[<ffffffffc0789328>] iwl_mvm_rx_rx_mpdu+0xa8/0xb88 [iwlmvm]
[<ffffffffc0632b40>] iwl_pcie_rx_handle+0x420/0xc48 [iwlwifi]

Tested with a Wireless AC 7265 for ~6 months, confirmed to fix the
problem. No other unaligned accesses are spotted yet.

Signed-off-by: Wang Xuerui <[email-masked]>
Signed-off-by: Luca Coelho <[email-masked]>
Signed-off-by: Kalle Valo <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 drivers/net/wireless/intel/iwlwifi/mvm/rx.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rx.c b/drivers/net/wireless/intel/iwlwifi/mvm/rx.c
index 0ad8ed23a4558..5ee33c8ae9d24 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/rx.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/rx.c
@@ -60,6 +60,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *****************************************************************************/
+#include <asm/unaligned.h>
 #include <linux/etherdevice.h>
 #include <linux/skbuff.h>
 #include "iwl-trans.h"
@@ -357,7 +358,7 @@ void iwl_mvm_rx_rx_mpdu(struct iwl_mvm *mvm, struct napi_struct *napi,
 	rx_res = (struct iwl_rx_mpdu_res_start *)pkt->data;
 	hdr = (struct ieee80211_hdr *)(pkt->data + sizeof(*rx_res));
 	len = le16_to_cpu(rx_res->byte_count);
-	rx_pkt_status = le32_to_cpup((__le32 *)
+	rx_pkt_status = get_unaligned_le32((__le32 *)
 		(pkt->data + sizeof(*rx_res) + len));
 
 	/* Dont use dev_alloc_skb(), we'll have enough headroom once
-- 
2.20.1