[PATCH AUTOSEL 4.19 150/177] iwlwifi: mvm: fix unaligned read of rx_pkt_status

Sasha Levin
2019-12-10T21:37:59Z

From: Wang Xuerui <wangxuerui@qiniu.com>

[ 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 <wangxuerui@qiniu.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 bfb163419c679..e6a67bc022090 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/rx.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/rx.c
@@ -62,6 +62,7 @@
* (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"
@@ -360,7 +361,7 @@ 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