airo: fix setting zero length WEP key

Patch prevents call set_wep_key() with zero key length. That fix long
standing regression since commit c0380693520b1a1e4f756799a0edc379378b462a
"airo: clean up WEP key operations". Additionally print call trace when
someone will try to use improper parameters, and remove key.len = 0
assignment, because it is in not possible code path.

Reported-by: Chris Siebenmann <cks-rhbugzilla@cs.toronto.edu>
Bisected-by: Chris Siebenmann <cks-rhbugzilla@cs.toronto.edu>
Tested-by: Chris Siebenmann <cks@cs.toronto.edu>
Cc: Dan Williams <dcbw@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 18 insertions, 16 deletions

diff --git a/drivers/net/wireless/airo.c b/drivers/net/wireless/airo.c
index 4331d675fcc6..2a9f029a3c74 100644
--- a/drivers/net/wireless/airo.c
+++ b/drivers/net/wireless/airo.c
@@ -5254,11 +5254,7 @@ static int set_wep_key(struct airo_info *ai, u16 index, const char *key,
         WepKeyRid wkr;
         int rc;
 
-        if (keylen == 0) {
-                airo_print_err(ai->dev->name, "%s: key length to set was zero",
-                               __func__);
-                return -1;
-        }
+        WARN_ON(keylen == 0);
 
         memset(&wkr, 0, sizeof(wkr));
         wkr.len = cpu_to_le16(sizeof(wkr));
@@ -6405,11 +6401,7 @@ static int airo_set_encode(struct net_device *dev,
                 if (dwrq->length > MIN_KEY_SIZE)
                         key.len = MAX_KEY_SIZE;
                 else
-                        if (dwrq->length > 0)
-                                key.len = MIN_KEY_SIZE;
-                        else
-                                /* Disable the key */
-                                key.len = 0;
+                        key.len = MIN_KEY_SIZE;
                 /* Check if the key is not marked as invalid */
                 if(!(dwrq->flags & IW_ENCODE_NOKEY)) {
                         /* Cleanup */
@@ -6590,12 +6582,22 @@ static int airo_set_encodeext(struct net_device *dev,
                 default:
                         return -EINVAL;
                 }
-                /* Send the key to the card */
-                rc = set_wep_key(local, idx, key.key, key.len, perm, 1);
-                if (rc < 0) {
-                        airo_print_err(local->dev->name, "failed to set WEP key"
-                                       " at index %d: %d.", idx, rc);
-                        return rc;
+                if (key.len == 0) {
+                        rc = set_wep_tx_idx(local, idx, perm, 1);
+                        if (rc < 0) {
+                                airo_print_err(local->dev->name,
+                                               "failed to set WEP transmit index to %d: %d.",
+                                               idx, rc);
+                                return rc;
+                        }
+                } else {
+                        rc = set_wep_key(local, idx, key.key, key.len, perm, 1);
+                        if (rc < 0) {
+                                airo_print_err(local->dev->name,
+                                               "failed to set WEP key at index %d: %d.",
+                                               idx, rc);
+                                return rc;
+                        }
                 }
         }