[PATCH] iwlwifi: mvm: fix an unaligned access

[PATCH] iwlwifi: mvm: fix an unaligned access

[wangxuerui]

From: Wang Xuerui <wangxuerui@qiniu.com>

Tested with a Wireless AC 7265 on a MIPS box, confirmed to fix the
unaligned accesses.

Signed-off-by: Wang Xuerui <wangxuerui@qiniu.com>
---
 drivers/net/wireless/intel/iwlwifi/mvm/rx.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rx.c b/drivers/net/wireless/intel/iwlwifi/mvm/rx.c
index 6653a238f32e..a155e816262e 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/rx.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/rx.c
@@ -57,6 +57,7 @@
  * (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"
@@ -355,8 +356,8 @@ 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 *)
-		(pkt->data + sizeof(*rx_res) + len));
+	rx_pkt_status = le32_to_cpu(get_unaligned((__le32 *)
+		(pkt->data + sizeof(*rx_res) + len)));
 
 	/* Dont use dev_alloc_skb(), we'll have enough headroom once
 	 * ieee80211_hdr pulled.
-- 
2.16.1

Re: [PATCH] iwlwifi: mvm: fix an unaligned access

[Jonas Gorski]

Hi,

On Mon, 18 Feb 2019 at 19:40, <wangxuerui@qiniu.com> wrote:
>
> From: Wang Xuerui <wangxuerui@qiniu.com>
>
> Tested with a Wireless AC 7265 on a MIPS box, confirmed to fix the
> unaligned accesses.
>
> Signed-off-by: Wang Xuerui <wangxuerui@qiniu.com>
> ---
>  drivers/net/wireless/intel/iwlwifi/mvm/rx.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rx.c b/drivers/net/wireless/intel/iwlwifi/mvm/rx.c
> index 6653a238f32e..a155e816262e 100644
> --- a/drivers/net/wireless/intel/iwlwifi/mvm/rx.c
> +++ b/drivers/net/wireless/intel/iwlwifi/mvm/rx.c
> @@ -57,6 +57,7 @@
>   * (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"
> @@ -355,8 +356,8 @@ 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 *)
> -               (pkt->data + sizeof(*rx_res) + len));
> +       rx_pkt_status = le32_to_cpu(get_unaligned((__le32 *)
> +               (pkt->data + sizeof(*rx_res) + len)));

There's get_unaligned_le32() for that purpose.


Regards
Jonas

[PATCH v2] iwlwifi: mvm: fix unaligned read of rx_pkt_status

[Wang Xuerui]

Fixed redundant calls per review.

Sorry for the delay; I inadvertently broke my test box and it took some
time to fix.

[PATCH] iwlwifi: mvm: fix unaligned read of rx_pkt_status

[Wang Xuerui]

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>
Tested-by: Wang Xuerui <wangxuerui@qiniu.com>
---
 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 6653a238f32e..a9f35799e532 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/rx.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/rx.c
@@ -57,6 +57,7 @@
  * (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"
@@ -355,7 +356,7 @@ 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
-- 
2.16.1

Re: [PATCH] iwlwifi: mvm: fix unaligned read of rx_pkt_status

[Luca Coelho]

On Sat, 2019-02-23 at 16:35 +0800, Wang Xuerui wrote:
> 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>
> Tested-by: Wang Xuerui <wangxuerui@qiniu.com>
> ---

Thanks! I have applied this to our internal tree and it will reach the
mainline following our normal upstreaming process.

--
Cheers,
Luca.