hostap: avoid uninitialized variable use in hfa384x_get_rid

commit 48dc5fb3ba53b20418de8514700f63d88c5de3a3 upstream.

The driver reads a value from hfa384x_from_bap(), which may fail,
and then assigns the value to a local variable. gcc detects that
in in the failure case, the 'rlen' variable now contains
uninitialized data:

In file included from ../drivers/net/wireless/intersil/hostap/hostap_pci.c:220:0:
drivers/net/wireless/intersil/hostap/hostap_hw.c: In function 'hfa384x_get_rid':
drivers/net/wireless/intersil/hostap/hostap_hw.c:842:5: warning: 'rec' may be used uninitialized in this function [-Wmaybe-uninitialized]
  if (le16_to_cpu(rec.len) == 0) {

This restructures the function as suggested by Russell King, to
make it more readable and get more reliable error handling, by
handling each failure mode using a goto.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/drivers/net/wireless/hostap/hostap_hw.c b/drivers/net/wireless/hostap/hostap_hw.c
index 6307a4e36c850c972e84974243f7f65de21724ee..f8639003da95c2eff55a079a8a03e12471175c56 100644 (file)
--- a/drivers/net/wireless/hostap/hostap_hw.c
+++ b/drivers/net/wireless/hostap/hostap_hw.c
@@ -836,25 +836,30 @@ static int hfa384x_get_rid(struct net_device *dev, u16 rid, void *buf, int len,
        spin_lock_bh(&local->baplock);
 
        res = hfa384x_setup_bap(dev, BAP0, rid, 0);
-       if (!res)
-               res = hfa384x_from_bap(dev, BAP0, &rec, sizeof(rec));
+       if (res)
+               goto unlock;
+
+       res = hfa384x_from_bap(dev, BAP0, &rec, sizeof(rec));
+       if (res)
+               goto unlock;
 
        if (le16_to_cpu(rec.len) == 0) {
                /* RID not available */
                res = -ENODATA;
+               goto unlock;
        }
 
        rlen = (le16_to_cpu(rec.len) - 1) * 2;
-       if (!res && exact_len && rlen != len) {
+       if (exact_len && rlen != len) {
                printk(KERN_DEBUG "%s: hfa384x_get_rid - RID len mismatch: "
                       "rid=0x%04x, len=%d (expected %d)\n",
                       dev->name, rid, rlen, len);
                res = -ENODATA;
        }
 
-       if (!res)
-               res = hfa384x_from_bap(dev, BAP0, buf, len);
+       res = hfa384x_from_bap(dev, BAP0, buf, len);
 
+unlock:
        spin_unlock_bh(&local->baplock);
        mutex_unlock(&local->rid_bap_mtx);